0000000000464742

AUTHOR

Romuald Lepers

Réponses cardiovasculaires lors de la distribution du courrier postal avec un vélo à assistance électrique

Cette etude a evalue les reponses cardiovasculaires lors de la distribution du courrier postal. Vingt-deux facteurs ont ete testes sur deux journees de travail, l’une realisee avec un velo electrique (VE), l’autre avec un velo traditionnel (VT). Les resultats ont montre une diminution significative (p < 0,05) de la frequence cardiaque moyenne avec l’utilisation d’un VE (90 ± 15 bpm) en comparaison d’un VT (94 ± 14 bpm), dont l’importance semble dependante du type de tournee realisee (type Pavillon vs. type Centre-ville). La duree de travail (≈ 660 min) et la depense energetique (≈ 330 Kcal) n’etaient pas affectees par le type de velo utilise. Le VE semble donc etre une alternative interessa…

research product

Differences in gender and performance in off-road triathlon.

The aims of this study were: (1) to examine performance trends and compare elite male and female athletes at the off-road triathlon (1.5-km swim, 30-km mountain biking, and 11-km trail running) world championships since its inception in 1996, and (2) to compare gender-related differences between off-road triathlon and conventional road-based triathlon. Linear regression analyses and ANOVA were used to examine performance trends and differences between the sexes. Elite male performance times stabilized over the 2005-2009 period, whereas elite female performance times continued to improve, especially for the run leg. Differences in performance times between the sexes were less marked in swimm…

research product

Neuromuscular Fatigue Following Isometric Contractions with Similar Torque Time Integral

International audience; Torque time integral (TTI) is the combination of intensity and duration of a contraction. The aim of this study was to compare neuromuscular alterations following different isometric sub-maximal contractions of the knee extensor muscles but with similar TTI. Sixteen participants performed 3 sustained contractions at different intensities (25 %, 50 %, and 75 % of Maximal Voluntary Contraction (MVC) torque) with different durations (68.5 +/- 33.4 s, 35.1 +/- 16.8 s and 24.8 +/- 12.9 s, respectively) but similar TTI value. MVC torque, maximal voluntary activation level (VAL), M-wave characteristics and potentiated doublet amplitude were assessed before and immediately a…

research product

Analysis of ultra-triathlon performances

Romuald Lepers1, Beat Knechtle2,3, Patrizia Knechtle2, Thomas Rosemann2 1INSERM U887, Faculty of Sport Sciences, University of Burgundy, Dijon, France; 2Institute of General Practice and Health Services Research, University of Zurich, Switzerland; 3Gesundheitszentrum St Gallen, St Gallen, Switzerland Abstract: Despite increased interest in ultra-endurance events, little research has examined ultra-triathlon performance. The aims of this study were: (i) to compare swimming, cycling, running, and overall performances in three ultra-distance triathlons, double Ironman distance triathlon (2IMT) (7.6 km swimming, 360 km cycling, and 84.4 km running), triple Ironman distance triathlon (3IMT) (11.…

research product

Differences in cardiorespiratory and neuromuscular responses between voluntary and stimulated contractions of the quadriceps femoris muscle.

The aim of this study was to compare respiratory gas exchange variables and muscle fatigue between equal-intensity (i.e., same force output) electrostimulated and voluntary contractions of the quadriceps muscle (46+/-10% of maximal voluntary force). Twelve healthy men served as volunteers. Oxygen consumption, ventilation and respiratory exchange ratio were recorded during the exercise bouts. Muscle fatigue was quantified as the exercise-induced reduction in maximal voluntary force. The average oxygen consumption (11+/-3 versus 8+/-2 mL min(-1)kg(-1)), ventilation (23+/-4 versus 16+/-2 L min(-1)) and respiratory exchange ratio (0.96+/-0.02 versus 0.85+/-0.01) were significantly higher during…

research product

Comparison of the 45-Second/15-Second Intermittent Running Field Test and the Continuous Treadmill Test

Purposes:To compare the physiological responses and maximal aerobic running velocity (MAV) during an incremental intermittent (45-s run/15-s rest) field test (45-15FIT) vs an incremental continuous treadmill test (TR) and to demonstrate that the MAV obtained during 45-15FIT (MAV45-15) was relevant to elicit a high percentage of maximal oxygen uptake (VO2max) during a 30-s/30-s intermittent training session.Methods:Oxygen uptake (VO2), heart rate (HR), and lactate concentration ([La]) were measured in 20 subjects during 2 maximal incremental tests and four 15-min intermittent tests. The time spent above 90% and 95% VO2max (t90% and t95% VO2max, respectively) was determined.Results:Maximal ph…

research product

Sex differences in 24-hour ultra-marathon performance - A retrospective data analysis from 1977 to 2012

OBJECTIVES: This study examined the changes in running performance and the sex differences between women and men in 24-hour ultra-marathons held worldwide from 1977 to 2012. METHOD: Changes in running speed and ages of the fastest 24-hour ultra-marathoners were determined using single- and multi-level regression analyses. RESULTS: From 1977 to 2012, the sex differences in 24-hour ultra-marathon performance were 4.6±0.5% for all women and men, 13.3% for the annual fastest finishers, 12.9±0.8% for the top 10 and 12.2±0.4% for the top 100 finishers. Over time, the sex differences decreased for the annual fastest finishers to 17%, for the annual 10 fastest finishers to 11.3±2.2% and for the ann…

research product

Participation and performance trends in 100-km ultra-marathons worldwide

The aims of the present study were to (1) investigate the participation trends for the origin of athletes competing in 100-km ultra-marathons and (2) determine the nationalities of athletes achieving the fastest 100-km race times worldwide. Race times and nationality from 112,283 athletes (15,204 women and 97,079 men) from 102 countries who completed a 100-km ultra-marathon worldwide between 1998 and 2011 were investigated using single- and multi-level regression analyses. The number of finishers increased exponentially, both for women and men. Most of the finishers (73.5%) were from Europe, in particular, France (30.4%). The number of finishers from Japan, Germany, Italy, Poland and the Un…

research product

Changes in neuromuscular function after tasks involving control of EMG versus torque feedback of the same duration.

This study was designed to compare alterations in neuromuscular function after two tasks of similar duration involving the control of (1) torque level fixed at 40% maximal voluntary contraction (MVC) torque (torque task) and (2) EMG level when exerting 40% MVC torque on the knee extensor muscles. Ten healthy subjects volunteered to participate in two testing sessions separated by approximately 2 h. Contraction duration for the EMG task was fixed for each subject to the time to task failure of the torque task (104+/-20s). MVC, maximal voluntary activation level, muscle compound action potential (M-wave), peak twitch and potentiated peak doublet were assessed before and immediately after each…

research product

Influence d'une supplémentation en vitamines sur le rendement de la locomotion après une épreuve d'ultratrail

International audience; Aim: The purpose of this study was to study changes in gross efficiency of locomotion after a prolonged trail running race (3000 m up and 300 m down). The second purpose was to investigate the effectiveness of supplementation in vitamin on gross efficiency variability.Materials and methods: Twenty-two well-trained endurance runners took part in this study. They had to perform four sub maximal tests before, 24, 48 and 72 hours after the race in order to estimate gross efficiency of locomotion and a maximal contraction test in the same period. They were divided in two groups either with supplementation (Isoxan Endurance ®) or without (placebo).Results: In both groups w…

research product

Central alterations of neuromuscular function and feedback from group III-IV muscle afferents following exhaustive high-intensity one-leg dynamic exercise

The aims of this investigation were to describe the central alterations of neuromuscular function induced by exhaustive high-intensity one-leg dynamic exercise (OLDE, study 1) and to indirectly quantify feedback from group III-IV muscle afferents via muscle occlusion (MO, study 2) in healthy adult male humans. We hypothesized that these central alterations and their recovery are associated with changes in afferent feedback. Both studies consisted of two time-to-exhaustion tests at 85% peak power output. In study 1, voluntary activation level (VAL), M-wave, cervicomedullary motor evoked potential (CMEP), motor evoked potential (MEP), and MEP cortical silent period (CSP) of the knee extensor…

research product

The effects of course length on freestyle swimming speed in elite female and male swimmers - a comparison of swimmers at national and international level

Abstract Freestyle swimming performance over 50 m, 100 m, 200 m, 400 m, 800 m and 1,500 m was compared on short (25 m) and long (50 m) course for 92,196 national swimmers (i.e. annual high score list Switzerland) and 1,104 international swimmers (i.e. finalists FINA World Championships) from 2000 to 2012. National and international swimmers of both sexes were on average 2.0 ± 0.6% faster on short than on long course. Sex-related differences in swimming speed were greater on short than on long course for international and national swimmers from 50 m to 800 m. Freestyle swimming performance improved across years for international swimmers in both short- and long-course whereas only male natio…

research product

Effect of mental fatigue on speed–accuracy trade-off

International audience; The aim of this study was to investigate the effects of mental fatigue on the duration of actual and imagined goal-directed arm movements involving speed-accuracy trade-off. Ten participants performed actual and imagined point-to-point arm movements as accurately and as fast as possible, before and after a 90-min sustained cognitive task inducing mental fatigue, and before and after viewing a neutral control task (documentary movie) that did not induce mental fatigue. Target width and center-to-center target distance were varied, resulting in five different indexes of difficulty. Prior to mental fatigue, actual and imagined movement duration increased with the diffic…

research product

Differences in Participation and Performance Trends in Age Group Half and Full Marathoners

International audience; Recent studies investigated participation and performance trends in age group half marathoners and full marathoners for a single event. The present study investigated participation and performance trends in age group athletes in all half marathons and full marathons held in a single country during a given period of time. Changes in running performance and age of 226,754 half marathoners and 86,419 full marathoners competing in Switzerland between 2000 and 2010 were analyzed using linear regression analyses. The number of half marathoners increased (P < 0.01) from 2000 to 2010 for both men (+231%) and women (+299%). In contrast, the number of male and female full mara…

research product

Age group athletes in inline skating: decrease in overall and increase in master athlete participation in the longest inline skating race in Europe - the Inline One-Eleven

Uwe Teutsch,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: Participation and performance trends in age group athletes have been investigated in endurance and ultraendurance races in swimming, cycling, running, and triathlon, but not in long-distance inline skating. The aim of this study was to investigate trends in participation, age, and performance in the longest inline race in Europe, the Inline One-E…

research product

Performance characteristics of Parkour practitioners: Who are the traceurs?

International audience; Parkour is a modern physical activity that consists of using the environment, mostly urban, as a playground of obstacles. The aims of this study were (i) to investigate age, anthropometric and training characteristics of Parkour practitioners, called ‘traceurs’ and (ii) to assess jump performances and muscular characteristics of traceurs, compared to those of gymnasts and power athletes. The mean age of the population of traceurs studied (n = 130) was 19.4 ± 4.3 years, women represented 12.4% of the total field and mean training volume was 8.1 ± 0.5 hours/week. Vertical and long jump performances were analysed on smaller samples of participants (four groups, n = 15 p…

research product

The age-related performance decline in ultraendurance mountain biking

Haupt, Samuel | Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph Alexander | Rosemann, Thomas | Lepers, Romuald; International audience; ''The age-related changes in ultraendurance performance have been previously examined for running and triathlon but not mountain biking. The aims of this study were (i) to describe the performance trends and (ii) to analyze the age-related performance decline in ultraendurance mountain biking in a 120-km ultraendurance mountain bike race the Swiss Bike Masters from 1995 to 2009 in 9,325 male athletes. The mean (+/- SD) race time decreased from 590 +/- 80 min to 529 +/- 88 min for overall finishers and from 415 +/- 8 min to 359 +/- 16 min for the top …

research product

Performance of Kenyan athletes in mountain versus flat marathon running - An example in Switzerland

Harm, C., Knechtle, B., Rust, A.C., Rosemann, T., Lepers, R. & Onywera, V. (2013). Performance of Kenyan athletes in mountain versus flat marathon running - An example in Switzerland. J. Hum. Sport Exerc., 8(4), pp.881-893. The purpose of this study was to compare running performance of Kenyans in a flat city marathon and a mountain marathon in Switzerland. Running times of top three overall Kenyan runners were compared with running times of top three overall runners of other nations in a mountain and a flat marathon held in Switzerland between 2003 and 2011. In the mountain marathon top three male Kenyans achieved with 199±23min the 11th fastest running time behind athletes from Italy (177…

research product

Assessment of the rate of force development scaling factor for the hip muscles

Introduction: The aim of this study was to evaluate test feasibility, validity, and reproducibility of the rate of force development scaling factor (RFD-SF) for the hip muscles. Methods: Feasibility was assessed as the testing compliance, validity as the ability to compute the RFD-SF from a linear regression, and reproducibility with a test–retest design in 20 healthy subjects. Reliability and agreement (reproducibility) were evaluated using intraclass correlation coefficient (ICC3,1) and percent standard error of measurement (SEM), respectively. Results: The RFD-SF testing protocol was completed successfully by all subjects, although the analysis had to be modified for hip rotators. Reliab…

research product

The effects of mental fatigue on sport-related performance

International audience; Mental fatigue is known to increase subjective feelings of fatigue and to decrease cognitive performance, but its impact on physical performance remains poorly understood. The aim of this chapter was to review the results of 29 studies published between 2009 and April 2018 and focusing on the impact of mental fatigue on sport-related performance. Taken all studies together, it appears that mental fatigue impairs endurance performance, motor skills performance and decision-making performance. However, maximal force production is not reduced in the presence of mental fatigue. These observations suggest that mental fatigue impairs sport-related performance during exerci…

research product

Time course of central and peripheral fatigue differs when maintaining a constant-EMG task vs. a constant-torque task

research product

Central European triathletes dominate Double Iron ultratriathlon – analysis of participation and performance 1985–2011

Katrin Sigg,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Patrizia Knechtle,2 Romuald Lepers,3 Thomas Rosemann11Institute of General Practice and Health Services Research, University of Zurich, Zurich; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: A recent study showed that European triathletes performed faster in Double Iron ultratriathlons than North American athletes. The present study analyzed triathletes participating in Double Iron ultratriathlons to determine the origin of the fastest Double Iron ultratriathletes, focusing on European countries.Methods: Participation and perf…

research product

Will women soon outperform men in open-water ultra-distance swimming in the ‘Maratona del Golfo Capri-Napoli’?

Abstract This study investigated the change in sex differences across years in ultra-distance swimming performances at the 36-km ‘Maratona del Golfo Capri-Napoli’ race held from 1954 to 2013. Changes in swimming performance of 662 men and 228 women over the 59-year period were investigated using linear, non-linear and hierarchical regression analyses. Race times of the annual fastest swimmers decreased linearly for women from 731 min to 391 min (r 2  = 0.60, p &lt; 0.0001) and for men from 600 min to 373 min (r 2  = 0.30, p &lt; 0.0001). Race times of the annual top three swimmers decreased linearly between 1963 and 2013 for women from 736.8 ± 78.4 min to 396.6 ± 4.5 min (r 2  = 0.58, p &lt…

research product

Participation and performance trends in ultra-triathlons from 1985 to 2009

We examined the changes in participation and performance trends in ultra-triathlons, from the Double Iron (7.6 km swimming, 360 km cycling, 84.4 km running) to the Deca Iron (38 km swimming, 1800 km cycling, 422 km running), between 1985 (first year of a Double Iron) and 2009 (25 years). The mean finish rate for all distances and races was 75.8%. Women accounted for ∼8-10% of the ultra-triathlons starters. For Double and Triple Iron, the number of finishers per year increased, from 17 to 98 and from 7 to 41, respectively. In the Deca Iron, the finishers per race have remained <20 since the first event was held, up to 2009. Concerning World best performances, the men were ∼19% faster than th…

research product

Sex difference in race performance and age of peak performance in the Ironman Triathlon World Championship from 1983 to 2012

Abstract Background The fastest Ironman race times in ‘Ironman Hawaii’ were achieved in very recent years. This study investigated the change in sex difference in both race performance and the age of peak performance across years in the top ten athletes for split disciplines and overall race time in the ‘Ironman Hawaii’ between 1983 and 2012. Methods Changes in split times, overall race times, and age of athletes across years for the top ten overall and the fastest swimmers, cyclists, and runners were investigated using regression analyses and analyses of variance. Results Between 1983 and 2012, the overall top ten men and women finishers improved their swimming (only men), cycling, running…

research product

Stability of pedalling mechanics during a prolonged cycling exercise performed at different cadences.

The aim of this study was to analyse the effect of pedalling rate on the pattern of mechanical torque application and on neuromuscular fatigue during prolonged cycling exercise. Eleven well-trained individuals performed three 1-h pedalling sessions, at 50 rev.min-1, 110 rev.min-1 and a freely chosen cadence, at an intensity corresponding to 65% of their maximal aerobic power. The mechanical torque applied on the right pedal was recorded for 30 s every 5 min while pedalling. Contractile and neural properties of the quadriceps and hamstring muscles were analysed before and immediately after each of the three pedalling sessions. The post-exercise reduction in knee extensors maximal voluntary c…

research product

Muscle activation during cycling at different cadences: Effect of maximal strength capacity

International audience; The purpose of this study was to examine the influence of maximal strength capacity on muscle activation, during cycling, at three selected cadences: a low cadence (50 rpm), a high cadence (110 rpm) and the freely chosen cadence (FCC). Two groups of trained cyclists were selected on the basis of the different maximal isokinetic voluntary contraction values (MVCi) of their lower extremity muscles as follow: Fmin (lower MVCi group) and Fmax (higher MVCi group). All subjects performed three 4-min cycling exercises at a power output corresponding to 80 % of the ventilatory threshold under the three cadences. Neuromuscular activity of vastus lateralis (VL), rectus femoris…

research product

Estimation of Muscular Fatigue under Electromyostimulation Using CWT

International audience; The aims of this study are to investigate muscular fatigue and to propose a new fatigue index based on the continuous wavelet transform (CWT) which is compared to the standard fatigue indexes from literature. Fatigue indexes are all based on the electrical activity of muscles (electromyogram) acquired during an electrically stimulated contraction thanks to two modules (electromyostimulation + electromyography recording) that can analyze EMG signals in real time during electromyostimulation. The extracted parameters are compared with each other and their sensitivity to noise is studied. The effect of truncation of M waves is then investigated, enlightening the robustn…

research product

Best performances by men and women open-water swimmers during the ‘English Channel Swim’ from 1900 to 2010

Eichenberger, Evelyn | Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph Alexander | Rosemann, Thomas | Lepers, Romuald; International audience; ''Little research has examined ultra-endurance swimming performances. The 'English Channel Swim', where swimmers have to cover a distance of 32 km between England and France represents a unique long-distance, open-water, sea-swimming challenge, and each year swimmers from all over the world try to succeed in this challenge. The best times in minutes and the nationality of successful men and women swimmers were analysed from 1900 to 2010. A total of 1,533 swimmers (455 women and 1,078 men) from more than 40 countries have successfully completed…

research product

Central Contribution to Electrically Induced Fatigue depends on Stimulation Frequency

International audience; PURPOSE: This study analyzed the impact of several protocols of neuromuscular electrical stimulation (NMES), matched with a similar total torque-time integral, on muscle activation pathways and neuromuscular fatigue.METHODS: Ten young healthy participants (age: 24.6 +/- 4.2) performed 3 randomized NMES sessions on the triceps surae muscles with 20 Hz, 60 Hz or 100 Hz stimulation frequencies (pulse duration: 1 ms), with pulse amplitude (IES) set at 20 % of isometric maximal voluntary contraction (MVC). Muscle activity during NMES was assessed by means of the twitch, the soleus H-reflex and M wave responses evoked by single muscle stimulation at IES. Neuromuscular fati…

research product

Masters athletes: Age is just a number

research product

Multi axis representation and Euclidean distance of muscle fatigue indexes during evoked contractions

International audience; In this article, we proposed a new representation of muscular fatigue during evoked muscle contractions based on fatigue indexes such as peak to peak amplitude, RMS of the M wave, mean and median frequency and fatigue index calculated from continuous wavelet transform (I CWT). These new representations of muscle fatigue using multi axis represented and Euclidean distance give better insights on changes in physiological characteristics during muscle fatigue. This technique provides a fatigue index using several muscle characteristics. The use of other kinds of fatigue characteristics as force could also be possible.

research product

''Limits in endurance performance of octogenarian athletes''

TO THE EDITOR: A recent study of Trappe et al. (3) showed that the aerobic power of octogenarian lifelong endurance athletes was approximately double that of untrained octogenarians (38 vs. 21 ml·kg 1 ·min 1 ). These remarkable aerobic capacities are the highest ever recorded in this age group. However, the impact of the identified physiological capacities on actual endurance performances has not been addressed, as no running performance indicators of the octogenarian athletes were provided in this study. We hereby suggest that, although trained octogenarian athletes can achieve levels of aerobic fitness well above their untrained counterpart, as a group they actually have not yet reached t…

research product

Vitamin and Mineral Supplementation and Neuromuscular Recovery after a Running Race

International audience; Purpose: This double-blind study investigated the effects of vitamin and mineral complex supplementation on the neuromuscular function of the knee-extensor muscles after a prolonged trail running race. Methods: Twenty-two well-trained endurance runners took either placebo (Pl group) or vitamins and minerals (Vm group) for 21 d before the race and for 2 d after the race. Maximal voluntary contractions (MVC) and surface EMG activity of the vastus lateralis (VL) muscle were recorded before (pre) and 1 h (post), 24 h (post 24) and 48 h (post 48) after the race. Central activation ratio (CAR), neural (M-wave), and contractile (muscular twitch) properties of the quadriceps…

research product

Predictor variables of performance in recreational male long-distance inline skaters.

We investigated the associations between selected anthropometric and training characteristics with race time in 84 recreational male long-distance inline skaters at the longest inline marathon in Europe, the 'Inline One-eleven' over 111 km in Switzerland, using bi- and multivariate analysis. The mean (s) race time was 264 (41) min. The bivariate analysis showed that age (r = 0.30), body mass (r = 0.42), body mass index (r = 0.35), circumference of upper arm (r = 0.32), circumference of thigh (r = 0.29), circumference of calf (r = 0.38), skin-fold of thigh (r = 0.22), skin-fold of calf (r = 0.27), the sum of skin-folds (r = 0.43), percent body fat (r = 0.45), duration per training unit in in…

research product

Age of peak swim speed and sex difference in performance in medley and freestyle swimming – a comparison between 200 m and 400 m in Swiss elite swimmers

Vaso, M., Knechtle, B., Rust, C.A., Rosemann, T. & Lepers, R. (2013). Age of peak swim speed and sex difference in performance in medley and freestyle swimming ‐ A comparison between 200 m and 400 m in Swiss elite swimmers. J. Hum. Sport Exerc., 8(3), pp.954-965. The aims of the present study were to examine (i) the age of peak swim speed and (ii) the sex difference in peak swim times in 200m and 400m medley versus freestyle. Swim times and ages of 5,524 swimmers (2,785 males and 2,739 females) from the Swiss high score list from 2006 to 2010 were analyzed using one-way analysis of variance (ANOVA). The age of peak swim speed was younger for females (~20-21 years) compared to males (~22-25 …

research product

Predictor variables for a 100-km race time in male ultra-marathoners.

In 169 male 100-km ultra-marathoners, the variables of anthropometry, training, and prerace experience, in order to predict race time, were investigated. In the bivariate analysis, age ( r = .24), body mass ( r = .20), Body Mass Index ( r = .29), circumference of upper arm ( r = .26), percent body fat (r = .45), mean weekly running hours ( r = –.21), mean weekly running kilometers ( r = –.43), mean speed in training ( r = –.56), personal best time in a marathon ( r = .65), the number of finished 100-km ultra-runs ( r = .24), and the personal best time in a 100-km ultra-run ( r = .72) were associated with race time. Stepwise multiple regression showed that training speed ( p &lt; .0001), me…

research product

Changes in breaststroke swimming performances in national and international athletes competing between 1994 and 2011 -a comparison with freestyle swimming performances.

Abstract Background The purpose of the present study was to analyse potential changes in performance of elite breaststroke swimmers competing at national and international level and to compare to elite freestyle swimming performance. Methods Temporal trends in performance of elite breaststroke swimmers were analysed from records of the Swiss Swimming Federation and the FINA (Fédération Internationale de Natation) World Swimming Championships during the 1994–2011 period. Swimming speeds of elite female and male breaststroke swimmers competing in 50 m, 100 m, and 200 m were examined using linear regression, non-linear regression and analysis of variance. Results of breaststroke swimmers were …

research product

European dominance in multistage ultramarathons: an analysis of finisher rate and performance trends from 1992 to 2010

Mohannad Abou Shoak,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Romuald Lepers,3 Thomas Rosemann11Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: Participation and performance trends regarding the nationality of ultraendurance athletes have been investigated in the triathlon, but not in running. The present study aimed to identify the countries in which multistage ultramarathons were held around the world and the nationalities of successful finishers.Methods: Finisher rates and…

research product

Réponse physiologique et temps d’effort maximal lors d’exercices intermittents courus à la vitesse maximale aérobie

Le but de cette etude etait de comparer les reponses physiologiques et la duree d’exercice (i.e. le nombre maximal de repetitions) lors de trois types d’exercices intermittents courus a la vitesse maximale aerobie (VMA). Dix-huit sujets masculins sportifs ont realise, a une semaine d’intervalle, trois exercices intermittents de type 15 s-15 s, 30 s-30 s et 60 s-60 s. Au cours de ces exercices, la consommation maximale d’oxygene , la frequence cardiaque, la lactatemie ([La]), le quotient respiratoire et la duree totale d’exercice (tlim) ont ete mesures. Le tlim etait significativement (p < 0,01) plus long lors de l’exercice 30 s-30 s (1270 ± 390 s) par rapport a l’exercice 15 s-15 s (953 ± 2…

research product

Intérêts et limites de la neurostimulation percutanée dans l’évaluation de la fatigue musculaire

La stimulation electrique nerveuse percutanee peut etre appliquee sur des muscles au repos ou lors de contractions volontaires pour examiner les mecanismes peripheriques et centraux de production de force a travers l’analyse de traces de force et de l’EMG evoque. La neurostimulation est largement utilisee pour evaluer la fonction neuromusculaire, pendant et apres un exercice fatigant, mais certaines precautions sont necessaires. L’analyse des caracteristiques de la secousse mecanique doit etre associee a celles de l’onde musculaire (onde M) pour investiguer pleinement le processus excitation-contraction. L’amplitude de la secousse pouvant etre influencee par des processus de fatigue et la p…

research product

Effet de l'imagerie motrice prolongée sur la preception de l'effort et ses corrélats neuronaux

National audience

research product

Time Course of Neuromuscular Alterations during a Prolonged Running Exercise

PLACE, N., R. LEPERS, G. DELEY, and G. Y. MILLET. Time Course of Neuromuscular Alterations during a Prolonged Running Exercise. Med. Sci. Sports Exerc., Vol. 36, No. 8, pp. 1347–1356, 2004. Purpose: This study investigated the time course of contractile and neural alterations of knee extensor (KE) muscles during a long-duration running exercise. Methods: Nine well-trained triathletes and endurance runners sustained 55% of their maximal aerobic velocity (MAV) on a motorized treadmill for a period of 5 h. Maximal voluntary contraction (MVC), maximal voluntary activation level (%VA), and electrically evoked contractions (single and tetanic stimulations) of KE muscles were evaluated before, aft…

research product

Analysis of swimming performance in FINA World Cup long-distance open water races

International audience; BACKGROUND: Age and peak performance in ultra-endurance athletes have been mainly investigated in long-distance runners and triathletes, but not for long-distance swimmers. The present study investigated the age and swimming performance of elite ultra-distance swimmers competing in the 5-, 10- and 25-km Fédération Internationale de Natation (FINA) World Cup swimming events. METHODS: The associations of age and swimming speed in elite male and female swimmers competing in World Cup events of 5-, 10- and 25-km events from 2000 to 2012 were analysed using single and multi-level regression analyses. RESULTS: During the studied period, the swimming speed of the annual top…

research product

Effet de l’imagerie motrice prolongée sur la perception de l’effort et ses corrélats neuronaux

International audience

research product

Changes in cortico-spinal excitability following uphill versus downhill treadmill exercise

International audience; An acute bout of aerobic exercise induces neuroplasticity in the motor cortex. Moreover, paired associative stimulation (PAS) is known to induce neuroplasticity in M1. However, the possible influence of the type of exercise on the neuroplastic changes remains unknown. The present study investigated the effects of two different modes of muscle contraction produced during locomotor exercise on changes in corticospinal (CS) excitability. Subjects performed two 30-min treadmill exercises at an intensity corresponding to 60% of their maximal heart rate with either a +10% (uphill) or -10% (downhill) slope. These exercises were followed or not by paired associative stimulat…

research product

Reduced performance difference between sexes in master mountain and city marathon running

Matthias A Zingg,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers3 1Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, France Background: The performance in master marathoners has been investigated in flat city marathons but not in mountain marathons. This study examined changes in the sex differences in performance across time in female and male master runners competing in a mountain marathon compared to a flat city marathon. Methods: The association between age and perform…

research product

Freestyle versus butterfly swimming performance – effects of age and sex

AbstractPurpose. Recent studies have suggested that the age of peak freestyle swimming speed is reached earlier in life in women than in men. However, no study has investigated the age of peak swimming speed in other swimming styles such as butterfly. The aims of the present study were to investigate the age of peak swimming speed in elite male and female butterfly and freestyle swimmers at the national level (Switzerland) and the sex differences in both the age of peak swimming speed and swimming speed for both swimming styles. Methods. Results of the elite Swiss swimmers between 2006 and 2010 were analysed using one-way analysis of variance. Results. In butterfly, women achieved peak swim…

research product

A comparison of medley and freestyle performance for national and international swimmers between 1994 and 2011.

Christof Buhl,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3Faculty of Sport Sciences, University of Burgundy, Dijon, FranceAbstract: The change in swim performance over time has been investigated for freestyle, but not for other strokes, such as in the medley. The aim of the study was to examine changes in 200 m and 400 m swim performances in medley swimmers at national (Switzerland) and international level (world championship finals) from 1994 to 2011. The 200 m and 400 m freestyle per…

research product

''Sex Differences In Ultra-triathlon Performance At Increasing Race Distance''

Ruest, Christoph Alexander | Knechtle, Beat | Knechtle, Patrizia | Rosemann, Thomas | Lepers, Romuald; International audience; ''It has been argued that women should be able to outrun men in ultra-endurance distances. The present study investigated the sex difference in overall race times and split times between elite female and male Ironman triathletes competing in Ironman Hawaii (3.8 km swimming, 180 km cycling, and 42.195 km running) and Double Iron ultra-triathletes (7.6 km swimming, 360 km cycling, and 84.4 km running). Data from 20,638 athletes, including 5,163 women and 15,475 men competing in Ironman Hawaii and from 143 women and 1,252 men competing in Double Iron ultra-triathlon ra…

research product

Rehabilitation and return to sport after bilateral open surgery for femoroacetabular impingement in a professional ice hockey player: A case report

International audience; Background: The aim of this case report was to describe the rehabilitation and return to sport of a professional ice hockey player with symptomatic femoroacetabular impingement (FM) after bilateral open hip surgery.Case description: A 21-year-old professional ice hockey player with symptomatic FAT underwent bilateral surgical hip dislocations within a 6-week time period. After the second surgery (right hip), he experienced right hip pain due to iliotibial band dehiscence, which required additional revision surgery. The athlete underwent a standardized rehabilitation protocol. Hip muscle strength was objectively assessed during rehabilitation.Outcomes: Iliotibial band…

research product

A comparison of performance of Deca Iron and Triple Deca Iron ultra-triathletes

This study intended to compare the performance of ultra-triathletes competing in a Deca Iron ultra-triathlon (i.e. 10 times 3.8 km swimming, 180 km cycling, and 42.2 km running) with the performance of athletes competing in a Triple Deca Iron ultra-triathlon (i.e. 30 times 3.8 km swimming, 180 km cycling, and 42.2 km running). Split and overall race times of six male finishers in a Deca Iron ultra-triathlon and eight male finishers in a Triple Deca Iron ultra-triathlon were analysed using multiple t-tests, linear and non-linear regression analyses, and analysis of variance. Among the 19 starters (i.e. 17 men and two women) in the Deca Iron ultra-triathlon, six men (i.e. 35.3% of all starter…

research product

Age-Related Decline in Olympic Triathlon Performance: Effect of Locomotion Mode

This study describes the decline in performance with age during Olympic triathlon Age Groups World Championships among the different locomotion modes. Mean performance of top 10 performers were analyzed for each group of age using the exponential model proposed by Baker, Tang, and Turner (2003, Experimental Aging Research, 29, 47-65). Comparison in performance decline was done between locomotion modes. Decline in performance in triathlon as a function of age follows an exponential model. A significant interaction effect between age and locomotion mode was observed on performance values. In swimming, a significant decrease was observed close to 5% per year after 45 years. Decline in performa…

research product

Sex and age-related differences in performance in a 24-hour ultra-cycling draft-legal event - a cross-sectional data analysis

International audience; BackgroundThe purpose of this study was to examine the sex and age-related differences in performance in a draft-legal ultra-cycling event.MethodsAge-related changes in performance across years were investigated in the 24-hour draft-legal cycling event held in Schötz, Switzerland, between 2000 and 2011 using multi-level regression analyses including age, repeated participation and environmental temperatures as co-variables.ResultsFor all finishers, the age of peak cycling performance decreased significantly (β = −0.273, p = 0.036) from 38 ± 10 to 35 ± 6 years in females but remained unchanged (β = −0.035, p = 0.906) at 41.0 ± 10.3 years in males. For the annual faste…

research product

Women Outperform Men in Ultra-Distance Swimming - The 'Manhattan Island Marathon Swim' From 1983 to 2013

Purpose:Recent studies suggested that women’s and men’s ultraswim performances may be similar for distances of ~35 km. The current study investigated both the gender difference and the age of peak ultraswim performance between 1983 and 2013 at the 46-km Manhattan Island Marathon Swim with water temperatures &lt;20°C.Methods:Changes in race times and gender difference in 551 male and 237 female finishers were investigated using linear-, nonlinear-, and hierarchical multilevel-regression analyses.Results:The top 10 race times ever were significantly (P &lt; .0001) lower for women (371 ± 11 min) than for men (424 ± 9 min). Race times of the annual fastest and annual 3 fastest women and men did…

research product

Participation and Performance Trends in Triple Iron Ultra-triathlon – a Cross-sectional and Longitudinal Data Analysis

Purpose: The aims of the present study were to investigate (i) the changes in participation and performance and (ii) the gender difference in Triple Iron ultra-triathlon (11.4 km swimming, 540 km cycling and 126.6 km running) across years from 1988 to 2011. Methods: For the cross-sectional data analysis, the association between with overall race times and split times was investigated using simple linear regression analyses and analysis of variance. For the longitudinal data analysis, the changes in race times for the five men and women with the highest number of participations were analysed using simple linear regression analyses. Results: During the studied period, the number of finishers …

research product

Master runners dominate 24-h ultramarathons worldwide—a retrospective data analysis from 1998 to 2011

Abstract Background The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. Methods Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. Results The number of 24-h ultra-marathoners increased for both women and men across years (P &lt; 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 ± 5.2 years f…

research product

Cycling exercise and the determination of electromechanical delay.

The main aim of the present paper was to address the validity of a methodology proposed in a previous paper [Li L, Baum BS. Electromechanical delay estimated by using electromyography during cycling at different pedaling frequencies. J Electromyogr Kinesiol 2004;14(6):647-52], aimed at determining the electromechanical delay from pedaling exercise performed at various cadences. Twelve trained subjects undertook pedaling bouts corresponding to combinations of cadences ranging from 50 to 100 RPM and power output from 37.5% to 75% of Pmax. As cadence increased, peak torque angle was found to shift forward in crank cycle (from 60-65 degrees at 50 RPM to 75-80 degrees at 100 RPM, depending on th…

research product

Predictor variables for a half marathon race time in recreational male runners

Christoph Alexander R&amp;uuml;st1, Beat Knechtle1,2, Patrizia Knechtle2, Ursula Barandun1, Romuald Lepers3, Thomas Rosemann11Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U887, University of Burgundy, Faculty of Sport Sciences, Dijon, FranceAbstract: The aim of this study was to investigate predictor variables of anthropometry, training, and previous experience in order to predict a half marathon race time for future novice recreational male half marathoners. Eighty-four male finishers in the &amp;lsquo;Half Marathon Basel&amp;rsquo; completed the race distance within (me…

research product

''Sex Difference In Open-water Ultra-swim Performance In the Longest Freshwater Lake Swim In Europe''

Eichenberger, Evelyn | Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph A. | Rosemann, Thomas | Lepers, Romuald | Senn, Oliver; International audience; ''This study examined participation and performance trends in the 26.4-km open-water ultra-swim "Marathon Swim in Lake Zurich," Switzerland. A total of 461 athletes (157 women and 304 men) finished the race between 1987 and 2011. The mean age of the finishers during the studied period was 32.0 +/- 6.5 years for men and 30.9 +/- 7.2 years for women. The mean age of finishers and the age of winners increased significantly across years for both sexes (p 0.05). The swimming time performance remained stable (p > 0.05) for both sexes across …

research product

Age and gender interactions in short distance triathlon performance

International audience; Abstract This study investigated the participation and performance trends as well as the age and gender interaction at the Olympic distance 'Zürich Triathlon' (1.5 km swim, 40 km cycle and 10 km run) from 2000 to 2010 in 7,939 total finishers (1,666 females and 6,273 males). Female triathletes aged from 40 to 54 years significantly (P < 0.05) increased their participation while the participation of younger females and males remained stable. Males of 50-54 years of age and females of 45-49 years of age improved their total race time. For elite top five overall triathletes, mean gender differences in swimming, cycling, running and overall race time were 15.2 ± 4.6%, 13…

research product

Neuromuscular fatigue following high versus low-intensity eccentric exercise of biceps brachii muscle

International audience; Purpose: This study investigated neuromuscular fatigue following high versus low-intensity eccentric exercise corresponding to the same amount of work.Methods: Ten volunteers performed two eccentric exercises of the elbow flexors: a high-intensity versus a low-intensity exercise. Maximal voluntary contraction torque and surface electromyography of the biceps brachii muscle were recorded before, immediately and 48 h after exercises. Maximal voluntary activation level, neural (M-wave) and contractile (muscular twitch) properties of the biceps brachii muscle were analysed using electrical stimulation techniques.Results: Maximal voluntary contraction torque was significa…

research product

Will women outrun men in ultra-marathon road races from 50 km to 1,000 km?

Abstract It has been assumed that women would be able to outrun men in ultra-marathon running. The present study investigated the sex differences in running speed in ultra-marathons held worldwide from 50 km to 1,000 km. Changes in running speeds and the sex differences in running speeds in the annual fastest finishers in 50 km, 100 km, 200 km and 1,000 km events held worldwide from 1969–2012 were analysed using linear, non-linear and multi-level regression analyses. For the annual fastest and the annual ten fastest finishers, running speeds increased non-linearly in 50 km and 100 km, but not in 200 km and 1,000 km where running speeds remained unchanged for the annual fastest. The sex diff…

research product

The Effects of a Prolonged Running Exercise on Strength Characteristics

The aim of this study was to examine concentric, isometric, and eccentric strength reductions in the quadriceps muscle following a prolonged running exercise. Before and after a 2 h run (28.4+/-1.4 km) peak torque (PT) of the knee extensors at angular velocities of -120, -90, -60, 0, 60, 120, 180, 240 degrees x s(-1) using an isokinetic dynamometer, electromyographic (EMG) activity of the vastus lateralis (VL) and vastus medialis (VM) muscles and height of a counter movement jump were recorded in twelve well-trained triathletes. Counter movement jump performances decreased by 10% and PT values were all significantly lower (p < 0.01) at each angular velocity following the run. The torque los…

research product

Evolution of electromyographic signal, running economy, and perceived exertion during different prolonged exercises

International audience; The purpose of this study was to compare the electromyographic (EMG) signal of the vastus lateralis muscle obtained during a run section of a triathlon and at the end of a prolonged run performed at the same running velocity. Seven subjects were studied on three occasions: a 2 h 15 min triathlon (30 min swimming, 60 min cycling, and 45 min treadmill running at 75% of the maximal aerobic speed), a 2 h 15 min run, where the last 45 min (Prolonged Run, PR) were run at the same speed as the Triathlon Run (TR) on a motorized treadmill, and a 45 min Isolated Run (IR) performed at the same TR and PR velocity. The three experimental trials were randomised. Oxygen uptake (VO …

research product

Neuromuscular Differences Between Endurance-Trained, Power-Trained, and Sedentary Subjects

This study tested the hypothesis that neuromuscular characteristics of plantar flexor (PF) and knee extensor (KE) muscles explain differences of both performance in vertical jump and maximal voluntary isometric contraction (MVC) between endurance-trained (END, n = 9), power-trained (POW, n = 8), and sedentary subjects (SED, n = 8). Evoked twitch characteristics of PF and KE were measured. MVC, maximal voluntary activation (%VA) of KE, and performance in vertical jump were also measured. POW have higher maximal rate of twitch force development (MRFD) than SED and END for both PF (p < 0.05) and KE (p < 0.01); %VA and MVC were higher for POW and END than SED (p < 0.01). Higher performances wer…

research product

Personal best times in an Olympic distance triathlon and in a marathon predict Ironman race time in recreational male triathletes

Christoph Alexander R&amp;uuml;st1, Beat Knechtle1,2, Patrizia Knechtle2, Thomas Rosemann1, Romuald Lepers31Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U887, University of Burgundy, Faculty of Sport Sciences, Dijon, FranceBackground: The purpose of this study was to define predictor variables for recreational male Ironman triathletes, using age and basic measurements of anthropometry, training, and previous performance to establish an equation for the prediction of an Ironman race time for future recreational male Ironman triathletes.Methods: Age and anthropometry, train…

research product

Analysis of marathon performances of disabled athletes

Le but de cette etude etait d’analyser la participation et les performances sur marathon des athletes handisports en fauteuils roulants classiques (WC) et en fauteuils avec pedalage des bras ou Handbike (HC). L’âge et les performances chronometriques de tous les athletes ayant participe au marathon de New-York, dans les categories WC et HC, ont ete analyses entre 1999 et 2010. Durant cette periode, un total de 698 athletes WC (132 femmes et 566 hommes) et 776 athletes HC (141 femmes et 635 hommes) ont termine la course. Les femmes representaient 20 % du total des arrivants dans les deux categories. Les athletes en categorie WC etait significativement (P < 0,01) plus jeunes en comparaison de…

research product

QUANTIFICATION OF MUSCLE FATIGUE WITHWAVELET ANALYSIS BASED ON EMG DURING MYOELECTRICAL STIMULATION

6; International audience; We propose a device dedicated to real time analysis of electromyograms (EMG) under myoelectrical stimulation (ES). The muscular fatigue analysis, which is obtained by the use of a dedicated analog circuit and a processing part, is the main purpose of this study. The description of a hardware device which incorporates an electro-stimulator and an electromyogram amplifier combined to a computer is detailed. Then, we present a muscular fatigue analysis part based on wavelet decomposition in order to extract a fatigue index, which is confronted with synthetic and experimental data. We conclude that the CWT index applies well to M waves. The noise sensitivity is invest…

research product

Evidence of neuromuscular fatigue after prolonged cycling exercise

International audience; Purpose: The purpose of this study was to analyze the effects of prolonged cycling exercise on metabolic, neuromuscular, and biomechanical parameters. Methods: Eight well-trained male cyclists or triathletes performed a 2-h cycling exercise at a power output corresponding to 65% of their maximal aerobic power. Maximal concentric (CON; 60, 120, 240°s 1), isometric (ISO; 0°s 1), and eccentric (ECC; 120,-60°s 1) contractions, electromyographic (EMG) activity of vastus lateralis (VL) and vastus medialis (VM) muscles were recorded before and after the exercise. Neural (M-wave) and contractile (isometric muscular twitch) parameters of quadriceps muscle were also analyzed u…

research product

The Effect of Course Length on Individual Medley Swimming Performance in National and International Athletes

Abstract Effects of course length (25 m versus 50 m) and advances in performance of individual medley swimming were examined for men and women in Swiss national competitions and FINA World Championships during 2000-2011. Linear regression and analysis of variance (ANOVA) were used to analyse 200 m and 400 m race results for 26,081 swims on the Swiss high score list and 382 FINA finalists. Swiss and FINA swimmers of both sexes were, on average, 4.3±3.2% faster on short courses for both race distances. Sex-related differences in swim speed were significantly greater for FINA swimmers competing in short-course events than in long-course events (10.3±0.2% versus 9.7±0.3%, p&lt;0.01), but did no…

research product

Understanding mental fatigue and perception of effort to understand endurance performance

Lettre à l'éditeur ("Journal of Applied physiology" vol.118, no.10). Fait partie de : "Commentaries on Viewpoint: The two-hour marathon: what's the equivalent for women?". http://jap.physiology.org/content/118/10/1324#ref-list-2

research product

Participation and performance trends in multistage ultramarathons--the 'Marathon des Sables' 2003-2012

International audience; BackgroundThe purpose of this study was to investigate participation and performance changes in the multistage ultramarathon 'Marathon des Sables' from 2003 to 2012.MethodsParticipation and performance trends in the four- or six-stage running event covering approximately 250 km were analyzed with special emphasis on the nationality and age of the athletes. The relations between gender, age, and nationality of finishers and performance were investigated using regression analyses and analysis of variance.ResultsBetween 2003 and 2012, a number of 7,275 athletes with 938 women (12.9%) and 6,337 men (87.1%) finished the Marathon des Sables. The finisher rate in both women…

research product

Quadriceps Femoris Torque and EMG Activity in Seated versus Supine Position

To compare voluntary and electrically evoked knee extensor torque, surface electromyography (EMG), and activation level obtained under seated versus supine position, i.e., with shortened versus lengthened rectus femoris (RF) muscle.The knee extensor torque obtained during maximal voluntary contractions (MVC) and after single and paired stimuli applied at rest was measured under seated (i.e., 90 degrees hip angle) and supine (i.e., 180 degrees hip angle) conditions. The associated EMG activity from biarticular RF and monoarticular vasti was also recorded, and activation level was estimated by means of the twitch interpolation technique.Knee extensor MVC was 10.6% higher in the seated compare…

research product

Increase in finishers and improvement of performance of masters runners in the Marathon des Sables

Saskia Carolin Jampen,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Romuald Lepers,3 Thomas Rosemann11Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceAim: The aim of the study was to examine finisher and performance trends of ultrarunners in the Marathon des Sables, the world&amp;#39;s largest multistage ultramarathon.Methods: The age and running speed was analyzed for 6945 finishes of 909 women and 6036 men between 2003 and 2012 at the Marathon des Sables covering about 240 km in the Morocc…

research product

Sex differences in response to cognitive stress during a fatiguing contraction

This study compared the time to task failure for a submaximal fatiguing contraction in the presence and absence of a cognitive stressor in men and women. In study 1, 10 men and 10 women (22 ± 3 yr of age) performed an isometric fatiguing contraction at 20% maximal voluntary contraction force until task failure with the elbow flexor muscles during two separate sessions. Subjects performed a mental-math task during one of the fatiguing contractions that aimed to increase anxiety and stress (stressor session). Salivary cortisol and reported levels of arousal (visual analog scale for anxiety, and State-Trait Anxiety Inventory scores) were elevated during the stressor session compared with a co…

research product

Analysis of 10 km swimming performance of elite male and female open-water swimmers.

Abstract This study investigated trends in performance and sex difference in swimming speed of elite open-water swimmers at FINA 10 km competitions (i.e. World Cup races, European Championships, World Championships and Olympic Games). Swimming speed and sex difference in swimming speed of the fastest and the top ten women and men per event competing at 10 km open-water races between 2008 and 2012 were analysed using single and multi-level regression analyses. A total of 2,591 swimmers (i.e. 1,120 women and 1,471 men) finished 47 races. Swimming speed of the fastest women (1.35 ± 0.9 m/s) and men (1.45 ± 0.10 m/s) showed no changes across years. The mean sex difference in swimming speed for …

research product

Alterations of Neuromuscular Function After Prolonged Running, Cycling and Skiing Exercises

It is well known that impairment of performance resulting from muscle fatigue differs according to the types of contraction involved, the muscular groups tested and the exercise duration/intensity. Depending on these variables, strength loss with fatigue can originate from several sites from the motor cortex through to contractile elements. This has been termed 'task dependency of muscle fatigue'. Only recently have studies focused on the origin of muscle fatigue after prolonged exercise lasting 30 minutes to several hours. Central fatigue has been shown to contribute to muscle fatigue during long-distance running by using different methods such as the twitch interpolation technique, the ra…

research product

Unchanged H-reflex during a sustained isometric submaximal plantar flexion performed with an EMG biofeedback.

The aim of this study was to assess H-reflex plasticity and activation pattern of the plantar flexors during a sustained contraction where voluntary EMG activity was controlled via an EMG biofeedback. Twelve healthy males (28.0+/-4.8 yr) performed a sustained isometric plantar flexion while instructed to maintain summed EMG root mean square (RMS) of gastrocnemius lateralis (GL) and gastrocnemius medialis (GM) muscles fixed at a target corresponding to 80% maximal voluntary contraction torque via an EMG biofeedback. Transcutaneous electrical stimulation of the posterior tibial nerve was evoked during the contraction to obtain the maximal H-reflex amplitude to maximal M-wave amplitude ratio (…

research product

Wheelchair half-marathon and marathon performance: The ‘Oita International Wheelchair Marathon’ 1983-2011

Knechtle, B. & Lepers, R. (2013). Wheelchair half-marathon and marathon performance ‐ the ‘Oita International Wheelchair Marathon’ 1983-2011. J. Hum. Sport Exerc., 8(4), pp.974-985. We compared participation and performance trends of individuals with disabilities competing in the half- and full-marathon in the ‘Oita International Wheelchair Marathon’ from 1981 to 2011. The performance times decreased during the 1980’s until the middle 1990’s and stabilized thereafter for both half-marathoners and marathoners. The mean top five overall finishers times were 0:52±0:07 h:min for half-marathoners and 1:36 ±0:11 h:min for marathoners, respectively. The mean age of the finishers increased signific…

research product

Performance and Age of the Fastest Female and Male 100-km Ultramarathoners Worldwide From 1960 to 2012

International audience; The purpose of this cross-sectional study was to investigate the change in 100-km running performance and in the age of peak performance for 100-km ultramarathoners. Age and running speed of the annual fastest women and men in all 100-km ultramarathons held worldwide between 1960 and 2012 were analyzed in 148,017 finishes with 18,998 women and 129,019 men using single, multivariate, and nonlinear regressions. Running speed of the annual fastest men increased from 8.67 to 15.65 km.h(-1) and from 8.06 to 13.22 km.h(-1) for the annual fastest women. For the annual 10 fastest men, running speed increased from 10.23 ± 1.22 to 15.05 ± 0.29 km.h(-1) (p < 0.0001) and for the…

research product

Changes in transition times in ‘Ironman Hawaii’ between 1998 and 2013

International audience; BackgroundRecent findings showed that elite Ironman triathletes competing in ‘Ironman Hawaii’ improved both split and overall race times. The present study investigated whether elite athletes also improved in transition time (i.e. time needed between disciplines for changing clothes and equipment).MethodsChanges in split times, overall race times and transition times (i.e. expressed in absolute and relative terms) in the annual fastest competing in ‘Ironman Hawaii’ were investigated using linear, non-linear and multi-level regression analyses. To detect a potential difference in transition times between different race distances, we compared transition times in ‘Ironm…

research product

Physiological and cognitive responses when riding an electrically assisted bicycle versus a classical bicycle

Theurel, J. | Theurel, A. | Lepers, R.; International audience; ''The present study compared the physiological responses and the subsequent cognitive performance when riding an electrically assisted (EB) versus a classical (CB) bicycle. Oxygen uptake, heart rate and leg extensor muscles electromyographic (EMG) activity were recorded in 10 subjects during a 30-min intermittent cycling exercise performed with EB versus CB. Cognitive performance was evaluated by a mail sorting test, performed at rest and after each cycling session. Averaged oxygen uptake and heat rate were significantly (P < 0.05) lower during EB cycling than during CB cycling. The EMG activities of the vastus lateralis, rectu…

research product

Age, training, and previous experience predict race performance in long-distance inline skaters, not anthropometry

Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph Alexander | Rosemann, Thomas | Lepers, Romuald; International audience; ''The association of characteristics of anthropometry, training, and previous experience with race time in 84 recreational, long-distance, inline skaters at the longest inline marathon in Europe (111 km), the Inline One-eleven in Switzerland, was investigated to identify predictor variables for performance. Age, duration per training unit, and personal best time were the only three variables related to race time in a multiple regression, while none of the 16 anthropometric variables were related. Anthropometric characteristics seem to be of no importance for a fast …

research product

Performance in Olympic triathlon: changes in performance of elite female and male triathletes in the ITU World Triathlon Series from 2009 to 2012

Abstract This study investigated the changes in performance and sex difference in performance of the world best triathletes at the ITU (International Triathlon Union) World Triathlon Series (i.e. 1.5 km swimming, 40 km cycling and 10 km running) during the 2009-2012 period including the 2012 London Olympic Games. Changes in overall race times, split times and sex difference in performance of the top ten women and men of each race were analyzed using single and multi-level regression analyses. Swimming and running split times remained unchanged whereas cycling split times (ß = 0.003, P &lt; 0.001) and overall race times (ß = 0.003, P &lt; 0.001) increased significantly for both women and men…

research product

Age and gender difference in non-drafting ultra-endurance cycling performance - the 'Swiss Cycling Marathon'.

Abstract Background In recent years, there was an increased interest in investigating the gender difference in performance and the age of peak performance in ultra-endurance performances such as ultra-triathlon, ultra-running, and ultra-swimming, but not in ultra-cycling. The aim of the present study was to analyze the gender difference in ultra-cycling performance and the age of peak ultra-cycling performance in the 720-km ‘Swiss Cycling Marathon’, the largest European qualifier for the ‘Race Across America’. Methods Changes in the cycling speed and age of 985 finishers including 38 women and 947 men competing in the Swiss Cycling Marathon from 2001 to 2012 covering a distance of 720 km wi…

research product

Participation and performance trends in ultracycling

Mohannad Abou Shoak,1 Beat Knechtle,1,2 Patrizia Knechtle,2 Christoph Alexander R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: Participation and performance trends have been investigated in ultramarathons and ultratriathlons but not in ultracycling. The aim of the present study was to investigate (1) participation and performance trends in ultraendurance cyclists, (2) changes in cycling speed over the years, and (3) the age of the fastest male…

research product

Performance and age of African and non-African runners in half- and full marathons held in Switzerland, 2000&amp;ndash;2010

Andr&amp;eacute; Aschmann,1 Beat Knechtle,2 Marco Cribari,1 Christoph Alexander R&amp;uuml;st,1 Vincent Onywera,3 Thomas Rosemann,1 Romuald Lepers4 1Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3Department of Recreation Management and Exercise Science, Kenyatta University, Kenya; 4Institut National de la Sant&amp;eacute; et de la Recherche M&amp;eacute;dicale, Faculty of Sport Sciences, University of Burgundy, Dijon, France Background: Endurance running performance of African (AF) and non-African (NAF) athletes is investigated, with better performances seen for Africans. To d…

research product

Is Body Fat a Predictor of Race Time in Female Long-Distance Inline Skaters?

Purpose The aim of this study was to evaluate predictor variables of race time in female ultra-endurance inliners in the longest inline race in Europe. Methods We investigated the association between anthropometric and training characteristics and race time for 16 female ultra-endurance inline skaters, at the longest inline marathon in Europe, the ‘Inline One-eleven’ over 111 km in Switzerland, using bi- and multivariate analysis. Results The mean (SD) race time was 289.7 (54.6) min. The bivariate analysis showed that body height (r=0.61), length of leg (r=0.61), number of weekly inline skating training sessions (r=-0.51) and duration of each training unit (r=0.61) were significantly correl…

research product

A mixed FES/EMG system for real time analysis of muscular fatigue

International audience; In this article, we present a functional electrical stimulator allowing the extraction in real time of M-wave characteristics from resulting EMG recodings in order to quantify muscle fatigue. This system is composed of three parts. A Labview software managing the stimulation output and electromyogram (EMG) input signal, a hardware part amplifying the output and input signal and a link between the two previous parts which is made up from input/output module (NIdaq USB 6251). In order to characterize the fatigue level, the Continuous Wavelet Transform is applied yielding a local maxima detection. The fatigue is represented on a scale from 0 for a fine shaped muscle to …

research product

Finisher and performance trends in female and male mountain ultramarathoners by age group

Christoph Alexander R&amp;uuml;st,1 Beat Knechtle,1,2 Evelyn Eichenberger,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and for Health Services Research, University of Zurich, Zurich, 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3French Institute of Health and Medical Research, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: This study examined changes according to age group in the number of finishers and running times for athletes in female and male mountain ultramarathoners competing in the 78 km Swiss Alpine Marathon, the largest mountain ultramarathon in Europe and held in high alpine terrain.Methods: The association between age …

research product

Swimrun: An emerging new endurance sport

International audience; The swimrun is a new endurance team-sport based on two persons swimming and running alternatively through open water and mostly trails. The aim of this study was to analyse participation and performance trends for males, females and mixed duo team at the ÖTILLÖ Swimrun race (10 km open-water swimming and 65 km trail running). During the 2012–2016 period, the mean total time performance of the best athletes at the ÖTILLÖ Swimrun decreased significantly by 17 min/year for males, 40 min/year for mixed and 59 min/year for females duo, respectively. The difference in performance between the best males and females duo (26 ± 15%) was significantly greater compared to the di…

research product

Participation and performance trends in 'Ultraman Hawaii' from 1983 to 2012

Abstract Background Participation and performance trends have been investigated in a single stage Ironman triathlon such as the ‘Ironman Hawaii,’ but not for a multi-stage ultra-triathlon such as the ‘Ultraman Hawaii’ covering a total distance of 515 km. The aims of this study were to analyze (1) changes in participation and performance, (2) sex-related differences in overall and split time performances, and (3) the age of peak performance in Ultraman Hawaii. Methods Age and race times including split times for 98 women and 570 men who successfully finished Ultraman Hawaii (day 1 with 10-km swimming and 145-km cycling, day 2 with 276-km cycling, and day 3 with 84-km running) between 1983 an…

research product

Gender difference in cycling speed and age of winning performers in ultra-cycling – the 508-mile “Furnace Creek” from 1983 to 2012

We analysed (i) the gender difference in cycling speed and (ii) the age of winning performers in the 508-mile "Furnace Creek 508". Changes in cycling speeds and gender differences from 1983 to 2012 were analysed using linear, non-linear and hierarchical multi-level regression analyses for the annual three fastest women and men. Cycling speed increased non-linearly in men from 14.6 (s = 0.3) km · h(-1) (1983) to 27.1 (s = 0.7) km · h(-1) (2012) and non-linearly in women from 11.0 (s = 0.3) km · h(-1) (1984) to 24.2 (s = 0.2) km · h(-1) (2012). The gender difference in cycling speed decreased linearly from 26.2 (s = 0.5)% (1984) to 10.7 (s = 1.9)% (2012). The age of winning performers increas…

research product

Analysis of Hawaii ironman performances in elite triathletes from 1981 to 2007.

International audience; PURPOSE: To examine the improvement in swimming (3.8 km), cycling (180 km), running (42.2 km), and overall performances at the Hawaii Ironman Triathlon of elite males and females between 1981 and 2007. METHODS: Trends across years, gender differences in performance times in the three disciplines, and overall winning times of the top 10 males and females were analyzed. RESULTS: Overall performance time in the ironman decreased rapidly from 1981 but has remained stable since the late 1980s. From 1988 to 2007, linear regression analysis showed that change in swimming, cycling, running, and total performance for both males and females was less than 1.4% per decade, excep…

research product

Effect of cycling cadence on subsequent 3 km running performance in well trained triathletes * Commentary

Objectives: To investigate the effect of three cycling cadences on a subsequent 3000 m track running performance in well trained triathletes. Methods: Nine triathletes completed a maximal cycling test, three cycle-run succession sessions (20 minutes of cycling + a 3000 m run) in random order, and one isolated run (3000 m). During the cycling bout of the cycle-run sessions, subjects had to maintain for 20 minutes one of the three cycling cadences corresponding to 60, 80, and 100 rpm. The metabolic intensity during these cycling bouts corresponded approximately to the cycling competition intensity of our subjects during a sprint triathlon (> 80% VO2max). Results: A significant effect of the p…

research product

Age of peak performance in elite male and female Ironman triathletes competing in Ironman Switzerland, a qualifier for the Ironman world championship, Ironman Hawaii, from 1995 to 2011

Christoph Alexander R&amp;uuml;st,1 Beat Knechtle,1,2 Patrizia Knechtle,2 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and for Health Services Research, University of Zurich, 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: The age of peak performance in elite endurance athletes has been investigated for elite marathoners, but not for elite Ironman triathletes. The aim of this study was to analyze the age of peak performance in swimming (3.8 km), cycling (180 km), running (42 km), and overall race time for elite female and male Ironman triathletes competing in Ironman Switzerl…

research product

Runners in their forties dominate ultra-marathons from 50 to 3,100 miles

International audience; OBJECTIVES: This study investigated performance trends and the age of peak running speed in ultra-marathons from 50 to 3,100 miles. METHODS: The running speed and age of the fastest competitors in 50-, 100-, 200-, 1,000- and 3,100-mile events held worldwide from 1971 to 2012 were analyzed using single- and multi-level regression analyses. RESULTS: The number of events and competitors increased exponentially in 50- and 100-mile events. For the annual fastest runners, women improved in 50-mile events, but not men. In 100-mile events, both women and men improved their performance. In 1,000-mile events, men became slower. For the annual top ten runners, women improved in…

research product

Effets du port de collants de compression sur les performances musculaires après un exercice de type circuit training

Resume Objectif Le but de cette etude etait d’examiner l’effet du port de collants longs de compression pendant un circuit training , compose d’exercices sollicitant le cycle etirement-raccourcissement, sur les performances musculaires. Synthese des faits La vitesse lors de sprints de 20 m et la detente verticale ont ete analysees chez sept sujets masculins avant et apres un circuit training realise avec ou sans collants de compression. Conclusion Les reductions des performances lors des sprints et des sauts apres le circuit training etaient similaires avec ou sans le port de collants de compression. Les effets du port de collants de compression sur les performances musculaires sont neglige…

research product

Truncation effects on muscular fatigue indexes based on M waves analysis

International audience; In this paper, we investigate muscular fatigue. We propose a new fatigue index based on the continuous wavelet transform (CWT) and compare it with the standard fatigue indexes from literature. Fatigue indexes are all based on the electrical activity of muscles (electromyogram) acquired during an electrically stimulated contraction (ES). The stimulator and electromyogram system, which were presented in a previous work, allows real-time analysis. The extracted fatigue parameters are compared between each other and their sensitivity to noise is studied. The effect of truncation of M waves is then investigated, enlightening the robustness of the index obtained using CWT.

research product

Nation related participation and performance trends in ‘Ironman Hawaii’ from 1985 to 2012

Abstract Background This study examined participation and performance trends in ‘Ironman Hawaii’ regarding the nationality of the finishers. Methods Associations between nationalities and race times of 39,706 finishers originating from 124 countries in the ‘Ironman Hawaii’ from 1985 to 2012 were analyzed using single and multi-level regression analysis. Results Most of the finishers originated from the United States of America (47.5%) followed by athletes from Germany (11.7%), Japan (7.9%), Australia (6.7%), Canada (5.2%), Switzerland (2.9%), France (2.3%), Great Britain (2.0%), New Zealand (1.9%), and Austria (1.5%). German women showed the fastest increase in finishers (r2 = 0.83, p &lt; …

research product

Swimming performances in long distance open-water events with and without wetsuit.

International audience; BACKGROUND: Existing literature showed improved swimming performances for swimmers wearing wetsuits competing under standardized conditions in races held in pools on short to middle distances. Data about the influence of wetsuits on swimming performances in long and ultra-long open-water swimming races are missing. It is unknown whether the benefit of wearing wetsuits is comparable in men and women. The aim of this study was to investigate the influence of wearing a wetsuit on open-water swimming performances at the 26.4 km 'Marathon Swim in Lake Zurich' in Lake Zurich, Switzerland, and the 3.8 km Lake Ontario Swim Team-Race (LOST-Race) in Lake Ontario, Canada. METHO…

research product

Age and gender differences in half-Ironman triathlon performances - the Ironman 70.3 Switzerland from 2007 to 2010

Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,2 Thomas Rosemann,2 Romuald Lepers31Gesundheitszentrum St Gallen, St Gallen, Switzerland; 2Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: To date, the age-related decline and gender differences in performance have been investigated for both Olympic and Ironman distance triathlons, but not for the intermediate distance (ie, the half-Ironman distance triathlon covering 1.9 km swimming, 90 km cycling and 21.1 km running, Ironman 70.3&amp;reg;). We determined the age-related differences in performan…

research product

Participation and performance trends in multistage ultramarathons—the ‘Marathon des Sables’ 2003–2012

Abstract Background The purpose of this study was to investigate participation and performance changes in the multistage ultramarathon ‘Marathon des Sables’ from 2003 to 2012. Methods Participation and performance trends in the four- or six-stage running event covering approximately 250 km were analyzed with special emphasis on the nationality and age of the athletes. The relations between gender, age, and nationality of finishers and performance were investigated using regression analyses and analysis of variance. Results Between 2003 and 2012, a number of 7,275 athletes with 938 women (12.9%) and 6,337 men (87.1%) finished the Marathon des Sables. The finisher rate in both women (r 2 = 0.…

research product

Does a Mental Training Session Induce Neuromuscular Fatigue?

ROZAND, V., F. LEBON, C. PAPAXANTHIS, and R. LEPERS. Does a Mental Training Session Induce Neuromuscular Fatigue? Med. Sci. Sports Exerc., Vol. 46, No. 10, pp. 1981–1989, 2014. Mental training, as physical training, enhances muscle strength. Whereas the repetition of maximal voluntary contractions (MVC) induces neuromuscular fatigue, the effect of maximal imagined contractions (MIC) on neuromuscular fatigue remains unknown. Here, we investigated neuromuscular alterations after a mental training session including MIC, a physical training session including MVC, and a combined training session including both MIC and MVC of the elbow flexor muscles. Methods: Ten participants performed 80 MIC (d…

research product

Cardiorespiratory Changes During Prolonged Downhill Versus Uphill Treadmill Exercise

AbstractOxygen uptake (V̇O2), heart rate (HR), energy cost (EC) and oxygen pulse are lower during downhill compared to level or uphill locomotion. However, a change in oxygen pulse and EC during prolonged grade exercise is not well documented. This study investigated changes in cardiorespiratory responses and EC during 45-min grade exercises. Nine male healthy volunteers randomly ran at 75% HR reserve during 45-min exercise in a level (+1%), uphill (+15%) or downhill (−15%) condition. V̇O2 , minute ventilation (V̇E ) and end-tidal carbon dioxide (PetCO2) were recorded continuously with 5-min averaging between the 10th and 15th min (T1) and 40th and 45th min (T2). For a similar HR (157±3 bpm…

research product

Changes in isokinetic torque and muscular activity of elbow flexors muscles with age

This study examined the influence of aging on torque-angular velocity relationships for elbow flexion and the corresponding muscular activity levels in order to target the mechanisms involved in the eccentric muscle action in older adults. Maximal constant angular torque (CAT) at 90 degrees was measured at different angular velocities for concentric (CON; 60, 120, 180, 240 degrees s(-1)), isometric (ISO) and eccentric (ECC; -60, -120 degrees s(-1)) elbow flexor muscle actions in older (OG; 6 females and 4 males, 64-82 years) and young adult subjects (YG; 6 females, 6 males, 19-24 years) on an isokinetic dynamometer. Myoelectrical activity was quantified on biceps and triceps muscles, using …

research product

Age-related changes in ultra-triathlon performances

International audience; BackgroundThe age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in ultra-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron ultra-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron ultra-triathlon (38-km swimming, 1,800-km cycling and 420-km running).MethodsThe age and performances of 423 male Triple Iron ultra-triathletes and 119 male Deca Iron ultra-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA.Resu…

research product

Assessment of the reliability of central and peripheral fatigue after sustained maximal voluntary contraction of the quadriceps muscle

The aim of the present study was to further confirm the validity of measurements for characterizing neuromuscular alterations by establishing their reliability both before and after fatigue. Thirteen men (28 5 years) volunteered to participate in two separate identical sessions requir- ing the performance of a sustained maximal voluntary contraction (MVC) with the quadriceps muscle for 2 min. MVC and transcutaneous electrical stimulations were used before and immediately after the fatiguing contrac- tion to investigate the reliability of MVC torque, central activation, and peripheral variables (M-wave properties, peak twitch, peak doublet) within and between sessions. Based on previous and …

research product

Age and sex interactions in mountain ultramarathon running - the Swiss Alpine Marathon.

Evelyn Eichenberger,1 Beat Knechtle,1,2 Christoph Alexander R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: The aims of the study were to examine the (a) participation, (b) difference in running times between the sexes, and (c) age-related decline in the running times of ultramarathoner women and men competing in the Swiss Alpine Marathon from 1998 to 2011.Methods: The ultramarathoners competing in the Swiss Alpine Marathon were analyzed in ter…

research product

Analysis of sex differences in open-water ultra-distance swimming performances in the FINA World Cup races in 5 km, 10 km and 25 km from 2000 to 2012

International audience; BACKGROUND: The present study investigated the changes in swimming speeds and sex differences for elite male and female swimmers competing in 5 km, 10 km and 25 km open-water FINA World Cup races held between 2000 and 2012. METHODS: The changes in swimming speeds and sex differences across years were analysed using linear, non-linear, and multi-level regression analyses for the annual fastest and the annual ten fastest competitors. RESULTS: For the annual fastest, swimming speed remained stable for men and women in 5 km (5.50 ± 0.21 and 5.08 ± 0.19 km/h, respectively), in 10 km (5.38 ± 0.21 and 5.05 ± 0.26 km/h, respectively) and in 25 km (5.03 ± 0.32 and 4.58 ± 0.27…

research product

Participation and performance trends in ultra-triathlons from 1985 to 2009.

International audience; We examined the changes in participation and performance trends in ultra-triathlons, from the Double Iron (7.6 km swimming, 360 km cycling, 84.4 km running) to the Deca Iron (38 km swimming, 1800 km cycling, 422 km running), between 1985 (first year of a Double Iron) and 2009 (25 years). The mean finish rate for all distances and races was 75.8%. Women accounted for ∼8-10% of the ultra-triathlons starters. For Double and Triple Iron, the number of finishers per year increased, from 17 to 98 and from 7 to 41, respectively. In the Deca Iron, the finishers per race have remained <20 since the first event was held, up to 2009. Concerning World best performances, the men …

research product

Effect of cycling cadence on contractile and neural properties of knee extensors.

LEPERS, R., G. Y. MILLET, and N. A. MAFFIULETTI. Effect of cycling cadence on contractile and neural properties of knee extensors. Med. Sci. Sports Exerc., Vol. 33, No. 11, 2001, pp. 1882–1888. Purpose: This study investigated the effect of prior prolonged cycling exercise performed at different cadences on subsequent neuromuscular characteristics. Methods: Eight well-trained triathletes sustained 80% of their maximal aerobic power during 30 min at three cadences: the freely chosen cadence (FCC), FCC20%, and FCC20%. Maximal isometric and concentric (120°·s 1 and 240°·s 1 ) torques were recorded before and after the exercise. Central activation, neural (M-wave), and contractile (isometric mu…

research product

EMG artifacts removal during electrical stimulation, a CWT based technique

International audience; A technique of artifacts removal based on the continuous wavelet transform is presented. It uses common mother wavelets to find the temporal localization of stimulation artifacts on electromyogram (EMG) signal during an electrically evoked contraction of a muscle. This method can be used with standard stimulation pulse waveforms like monophasics or biphasics ones. It uses a histogram representation to find the best threshold to apply on the CWT domain. The algotithm is presented with Haar wavelet and then it is used with common wavelet famillies such as Daubechies or Symlets.

research product

Neuromuscular fatigue differs following unilateral vs bilateral sustained submaximal contractions

The purpose of the present study was to compare the mechanisms of fatigue induced by a unilateral vs a bilateral submaximal isometric knee extension. Ten physically active men completed two experimental sessions, randomly presented. They were asked to maintain an isometric knee extension force corresponding to 20% of the maximal voluntary contraction (MVC) until task failure with one leg (unilateral) vs two legs (bilateral). MVCs were performed before and after the sustained contraction. Transcutaneous electrical stimuli were used to examine central (voluntary activation) and peripheral (peak doublet force at rest) fatigue on the exercised leg. Time to task failure was significantly shorter…

research product

A real time electromyostimulator linked with EMG analysis device

International audience; In this study, a new system composed of two modules (electromyostimulation + electromyography recording) is presented. It can analyze in real time EMG signals during electromyostimulation. In addition, we propose a new method based on wavelet decomposition to analyze changes in M-wave characteristics. It leads to introduce a new index related to muscular fatigue.

research product

Influence of ultra-long-term fatigue on the oxygen cost of two types of locomotion.

The aim of this study was to examine the effects of fatigue induced by a 65-km ultramarathon on the oxygen cost of running (Cr) and cycling (Ccycl). The day before and immediately after the race, a group of nine well-trained male subjects performed two sub-maximal 4-min exercise bouts: one cycling at a power corresponding to 1.5 W · kg−1 body mass on an electromagnetically braked ergometer, and one running at 11 km · h−1 on a flat asphalt roadway. Before oxygen cost determinations, the subjects performed 12 “ankle” jumps at a given frequency that was fixed by an electronic metronome (2.5 Hz). From the non-fatigued to the fatigued condition, there was a significant increase in minute ventila…

research product

The aspect of nationality and performance in a mountain ultra-marathon-the ‘Swiss Alpine Marathon’

Eichenberger E, Knechtle B, Rust CA, Lepers R, Rosemann T, Onywera VO. The aspect of nationality and performance in a mountain ultra-marathon - the ‘Swiss Alpine Marathon’ J. Hum. Sport Exerc. Vol. 7, No. 4, pp. 748-762, 2012. Runners from East Africa and especially from Kenya dominate middle- and longdistance running races worldwide. The aim of the present study was to investigate the participation and performance trends regarding the nationality of runners in a mountain ultra-marathon held in partially high alpine terrain. We hypothesized that Kenyan runners, living and training in the Great Rift Valley, a predominantly hilly, mountainous and altitudinous region like the Alps, would domin…

research product

Analysis of performance and age of the fastest 100-mile ultra-marathoners worldwide

OBJECTIVES: The performance and age of peak ultra-endurance performance have been investigated in single races and single race series but not using worldwide participation data. The purpose of this study was to examine the changes in running performance and the age of peak running performance of the best 100-mile ultra-marathoners worldwide. METHOD: The race times and ages of the annual ten fastest women and men were analyzed among a total of 35,956 finishes (6,862 for women and 29,094 for men) competing between 1998 and 2011 in 100-mile ultra-marathons. RESULTS: The annual top ten performances improved by 13.7% from 1,132&#177;61.8 min in 1998 to 977.6&#177;77.1 min in 2011 for women and b…

research product

''Sex-related Trends In Participation and Performance In the 'swiss Bike Masters' From 1994-2012''

Gloor, Roman Urs | Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph Alexander | Haupt, Samuel | Rosemann, Thomas | Lepers, Romuald; International audience; ''General participation in contests such as ultra-marathons and ultra-triathlons has increased considerably over the past 30 years, especially among women. This study investigated performance trends in the Swiss Bike Masters, one of the first and most prestigious mountain bike, ultra-endurance races in its class, with comparisons of participation and performance trends to similar races. The development of performance in the Swiss Bike Masters held between 1994 and 2012 was investigated by analysing the number of finishers, their ag…

research product

Analysis of participation and performance in athletes by age group in ultramarathons of more than 200 km in length

Matthias Zingg,1 Beat Knechtle,1,2 Christoph A R&amp;uuml;st,1 Thomas Rosemann,1 Romuald Lepers3 1Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, France Background: Participation and performance trends for athletes by age group have been investigated for marathoners and ultramarathoners competing in races up to 161 km, but not for longer distances of more than 200 km. Methods: Participation and performance trends in athletes by age group in the Badwater (217 km) and Spartathlon (246 km) races were compared from…

research product

Alterations of neuromuscular function after an ultramarathon.

Neuromuscular fatigue of the knee extensor (KE) and plantar flexor (PF) muscles was characterized after a 65-km ultramarathon race in nine well-trained runners by stimulating the femoral and tibial nerves, respectively. One week before and immediately after the ultramarathon, maximal twitches were elicited from the relaxed KE and PF. Electrically evoked superimposed twitches of the KE were also elicited during maximal voluntary contractions (MVCs) to determine maximal voluntary activation. MVC and maximal voluntary activation decreased significantly after the ultramarathon (−30.2 ± 18.0% and −27.7 ± 13.0%, respectively; P &lt; 0.001). Surprisingly, peak twitch increased after the ultramara…

research product

Response to letter to the editor by T. D. Noakes

research product

Effets d'une complémentation nutritionnelle en vitamines et minéraux sur la chute de force et les marqueurs biologiques consécutifs à un exercice excentrique chez des personnes âgées

Purpose. – The effects of vitamins and minerals complex supplementation on maximal voluntary contraction decrease (FMV) and biological markers following an eccentric exercise at old people. Method. – Sixteen elderly subjects took either placebo (Pl group) or vitamins and minerals (Isoxan Senior, NHS, Rungis, France) (group S) for 21 d before an eccentric exercise and for 3 d after the exercise. The FMV and surface EMG activity (RMS) of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) were recorded before (Pre), immediately after (Post), 24 h (Post 24) and 48 h (Post 48) after the exercise. CCVThe creatine kinase (CK), lactate deshydrogenase, malondialdehyde, and tumor…

research product

Is Moderate Intensity Cycling Sufficient to Induce Cardiorespiratory and Biomechanical Modifications of Subsequent Running?

Walsh, JA, Dawber, JP, Lepers, R, Brown, M, and Stapley, PJ. Is moderate intensity cycling sufficient to induce cardiorespiratory and biomechanical modifications of subsequent running? J Strength Cond Res 31(4): 1078-1086, 2017-This study sought to determine whether prior moderate intensity cycling is sufficient to influence the cardiorespiratory and biomechanical responses during subsequent running. Cardiorespiratory and biomechanical variables measured after moderate intensity cycling were compared with control running at the same intensity. Eight highly trained, competitive triathletes completed 2 separate exercise tests; (a) a 10-minute control run (no prior cycling) and, (b) a 30-minut…

research product

Neuromuscular fatigue following constant versus variable-intensity endurance cycling in triathletes

International audience; The aim of this study was to determine whether variable power cycling produced greater neuromuscular fatigue of knee extensor muscles than constant power cycling at the same mean power output. Eight male triathletes (age : 33 ± 5 yr, mass : 74 ± 4 kg, OV&2max : 62 ± 5 ml.kg-1.min-1, maximal aerobic power : 392 ± 17 W) performed two 30 min trials on a cycle ergometer in a random order. Cycling exercise was performed either at a constant power output (CP) corresponding to 75% of the maximal aerobic power (MAP) or a variable power output (VP) with alternating ± 15%, ± 5%, and ± 10% of 75% MAP approximately every 5 min. Maximal voluntary contraction (MVC) torque, maximal…

research product

Neuromuscular function during prolonged pedalling exercise at different cadences

Aim: The purpose of the present work was to assess the strategies set by the central nervous system in order to provide the power output required throughout a prolonged (1-h) pedalling exercise performed at different cadences (50 rpm, 110 rpm and the freely chosen cadence). Methods: Neuromuscular (NM) activity of vastus lateralis, rectus femoris, biceps femoris and gastrocnemius lateralis muscles was studied quantitatively [root-mean square (RMS) and mean power frequency (MPF)] and qualitatively (timing of onset and offset of muscle bursts during crank cycle). Results: The present results showed that increased cadence resulted in earlier muscle activation in crank cycle. The influence of ca…

research product

Are Female Performances in Other Olympic Distance Running Events Equivalent to Paula Radcliffe's?

research product

Prolonged motor imagery increases motor-related cortical potential amplitude and perception of effort during imagined and actual isometric knee extensions

Thème du colloque : «Sport Science in a Metropolitan Area»; International audience

research product

Carbohydrate ingestion does not influence the change in energy cost during a 2-h run in well-trained triathletes

The aim of this study was to examine whether the increase in the energy cost of running (C(r)), previously reported to occur at the end of a prolonged run, could be influenced by the ingestion of either an artificially sweetened placebo (Pl) or a 5.5% carbohydrate (CHO) solution. Ten well-trained triathletes completed three testing sessions within a 3-week period. The aim of the first session was to determine maximal oxygen uptake (VO(2)(max)) and the velocity associated with ventilatory threshold (nu(VT)). The second and the third sessions were composed of two submaximal treadmill runs (20 min long, 0% grade, performed at nu(VT)), before and after an 80-min overground run, also conducted a…

research product

Effect of pedalling rates on physiological response during endurance cycling

International audience; This study was undertaken to examine the effect of different pedalling cadences upon various physiological responses during endurance cycling exercise. Eight well-trained triathletes cycled three times for 30 min each at an intensity corresponding to 80% of their maximal aerobic power output. The first test was performed at a freely chosen cadence (FCC); two others at FCC-20% and FCC +20%, which corresponded approximately to the range of cadences habitually used by road racing cyclists. The mean (SD) FCC, FCC-20% and FCC + 20% were equal to 86 (4), 69 (3) and 103 (5) rpm respectively. Heart rate (HR), oxygen uptake (VO2), minute ventilation (VE) and respiratory excha…

research product

Age-related changes in conventional road versus off-road triathlon performance

International audience; The aims of this study were: i) to analyze age-related declines in swimming, cycling, and running performances for road-based and off-road triathlons, and ii) to compare age-related changes in these three disciplines between road-based and off-road triathlons. Swimming, cycling, running and total time performances of the top 5 males between 20 and 70 years of age (in 5 year intervals) were analyzed for short distance road-based (1.5 km swim, 40 km cycle, and 10 km run) and off-road (1.5 km swim, 30 km mountain bike, and 11 km trail run) triathlons at the 2009 World Championships. Independently of age, there was a lesser age-related decline in cycling performance (P<0…

research product

Master triathletes have not reached limits in their Ironman triathlon performance

The purpose of this study was to analyze the participation and performance trends of male triathletes in the "Ironman Switzerland" from 1995 to 2010. Participation trends of all finishers aged between 18 and 64 years were analyzed over the 16-year period by considering four 4-year periods 1995-1998, 1999-2002, 2003-2006, and 2007-2010, respectively. The 3.8-km swimming, 180-km cycling, 42-km running times, and total race times were analyzed for the top 10 triathletes in each age group from 18 to 64 years. The participation of master triathletes (≥40 years old) increased over the years, representing on average 23%, 28%, 37%, and 48% of total male finishers during the four 4-year periods, res…

research product