The categorization of amateur cyclists as research participants: findings from an observational study.

Sampling bias is an issue for research involving cyclists. The heterogeneity of cyclist populations, on the basis of skill level and riding purpose, can generate incorrect inferences about one specific segment of the population of interest. In addition, a more accurate categorization would be helpful when physiological parameters are not available. This study proposes using self-reported data to categorize amateur cyclist types by varying skill levels and riding purposes, therefore improving sample selection in experimental studies. A total of 986 cyclists completed an online questionnaire between February and October 2016. Two-step cluster analyses were performed to generate distinct group…

Can exercise-induced muscle damage be related to changes in skin temperature?

Measurement of skin temperature using infrared thermography has become popular in sports, and has been proposed as an indicator of exercise-induced muscle damage after exercise. However, the relationship between skin temperature and exercise-induced muscle damage is still unclear. Here we set out to investigate the relationship between skin temperature and exercise-induced muscle damage.Twenty untrained participants completed a protocol of exercise for calf muscles. Before and after exercise blood samples were collected to determine creatine kinase and acetylcholinesterase activity. Thermal images were recorded from the exercised muscles to determine skin temperature. Delayed onset muscle s…

Effect of cycling specialization on effort and physiological responses to uphill and flat cycling at similar intensity

Power output is considered one of the best tools to control external loads in cycling, but the relationship between a target power output and the physiological responses may suffer from the effects of road gradient, which is also affected by cyclist specialization. The objective was to determine the effects of cyclist specialization on effort perception and physiological response (heart rate and lactate concentration) while sustaining efforts at similar power output but riding on two different road gradients. Nineteen male competitive road cyclists performed two randomized trials of 10 min at 0% (velodrome) and 10 min at 6% road gradient (field uphill), at an intensity of 10% ± 3% below the…

Multicomponent Training Prevents Memory Deficit Related to Amyloid-β Protein-Induced Neurotoxicity.

Background: Alzheimer’s disease (AD) is characterized by the accumulation of the amyloid-β peptide in the brain, leading to early oxidative stress and neurotoxicity. It has been suggested that physical exercise could be beneficial in preventing AD, but studies with multicomponent training are scanty. Objective: Verify the effects of multicomponent exercise training to prevent deficits in recognition memory related to Aβ neurotoxicity. Methods: We subjected Wistar rats to multicomponent training (including aerobic and anaerobic physical exercise and cognitive exercise) and then infused amyloid-β peptide into their hippocampus. Results: We show that long-term multicomponent training prevents …

Relationship between Skin Temperature, Electrical Manifestations of Muscle Fatigue, and Exercise-Induced Delayed Onset Muscle Soreness for Dynamic Contractions: A Preliminary Study

Delayed onset muscle soreness (DOMS) indicates the presence of muscle damage and impairs force production and control. Monitorization of DOMS is useful to improving recovery intervention plans. The magnitude of DOMS may relate to muscle fatigue, which can be monitored by surface electromyography (EMG). Additionally, growing interest has been expressed in determining whether the skin temperature over a muscle group during exercise to fatigue could be a non-invasive marker for DOMS. Here we determine whether skin temperature and manifestations of muscle fatigue during exercise are correlated and can predict DOMS after concentric&ndash

Relationship between skin temperature and muscle activation during incremental cycle exercise.

While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four …

Insights on the use of thermography in human physiology practical classes

Effects of different hydration supports on stride kinematics, comfort, and impact accelerations during running.

Background: Different supports for hydration can influence total body mass and affect running biomechanics. Research question: Do different hydration supports affect the perceived exertion and comfort, stride kinematics, and impact accelerations during running?. Methods: This was a crossover study design. Thirteen trail runners completed a treadmill running test divided into four different durations and randomized hydration supports conditions, lasting 8 min each at moderate intensity: A) waist bag (0.84 kg); B) medium load backpack (0.84 kg); C) full load backpack (3.40 kg); and D) a control condition without water support. Impact accelerations were measured for 30 s in 4, 6, and 8 min. Th…

Application of Infrared Thermography in the Assessment of Sport Equipment

Abstract Infrared thermography is a noninvasive imaging technique used to determine surface temperatures under controlled conditions. This technique has many applications in different fields, the assessment of sport equipment being one of them. This chapter aims to provide a general overview of the scientific literature regarding the application of infrared thermography for the assessment of sport equipment. Some examples are provided based on the recent literature and the background experience of the chapter authors in the use of infrared thermography in sport. Examples include the monitoring of formula one (F1) tires during racing, detection of technological doping in cycling, saddle fit …

Relationship between exercise-induced muscle soreness, pain thresholds, and skin temperature in men and women.

Abstract Infrared thermography (IRT) has gained popularity in sports medicine for determining whether changes in skin temperature relate to pain and muscle damage. Such a relationship would support IRT as a non-invasive method to monitor these physiological responses. However, the literature remains controversial. Here, we determine the relationship between exercise-induced muscle soreness (DOMS), pain, and skin temperature in men and women before and after exercise. Twenty-two physically active adults (10 men and 12 women) completed a squat exercise protocol to induce muscle damage. Skin temperature, DOMS, and pressure pain threshold (PPT) were assessed in the quadriceps pre, post-exercise…

A retrospective international study on factors associated with injury, discomfort and pain perception among cyclists

International audience; Although cycling has been associated with overuse/fatigue and acute injuries, there is lack of information regarding associated risk factors and prevention factors. The objective of the study was to determine the factors associated with injury, and perceptions of discomfort and pain in cyclists. A total of 739 cyclists completed an online questionnaire between February and October 2016. The questionnaire acquired information on participant demographics, characteristics related to cycling profile and fitness training, bike components and cycling posture, self-reported perceptions of comfort and pain, and injuries sustained in the last 12 months. Logistic regression mo…

The association of bike fitting with injury, comfort, and pain during cycling: An international retrospective survey

Although bike fitting is recommended to help reduce injury risk, little empirical evidence exists to indicate an association between bike fitting and injury incidence. The aim of the study was to determine the effect of bike fitting on self-reported injury, comfort, and pain while cycling from a worldwide survey of cyclists. A total of 849 cyclists completed an online questionnaire between February and October 2016. Questionnaire collected data on respondent demographics, cycling profile, bike fitting, comfort and pain while cycling, and injury history. The main predictor variable was bike fitting (yes, by the respondent, i.e. user bike fitting; yes, by a professional service; or no). Covar…

Influence of infrared camera model and evaluator reproducibility in the assessment of skin temperature responses to physical exercise.

Infrared thermography (IRT) has been gaining in popularity in clinical and scientific research due to the increasing availability of affordable infrared cameras. This study aims to determine the similarity of measurement performance between three models of IRT camera during assessment of skin temperature before and after physical exercise. Three models of FLIR thermographic cameras (E60bx, Flir-One Pro LT, and C2) were tested. Thermal images were taken of the foot sole, anterior leg, and anterior thigh from 12 well-trained men, before and after a 30-min run on a treadmill. Image files were blinded and processed by three evaluators to extract the mean, maximum, and standard deviation of skin…

Importance of static adjustment of knee angle to determine saddle height in cycling

Knee flexion angle is used to determine saddle height during pedaling. However, it is unclear if knee flexion angle at upright standing posture affects measures and interpretation of knee flexion angle during cycling. The objective of this study was to assess the importance of adjusting knee angle during pedaling according to the knee angle at upright posture. Seventeen cyclists performed three 10 min cycling trials at different saddle heights to induce knee flexion angles (40º, 30º or 20º when crank was at the 6 o'clock position). Knee flexion angle was determined at the sagittal plane during cycling using a 2D motion analysis system. Alteration of saddle height was performed by subtractin…

Methodological Aspects of Infrared Thermography in Human Assessment

Infrared thermography presents some important advantages in the determination of skin temperature, as it is a safe, non-invasive and non-contact technique with wide applications in the field of sports sciences. Like many others techniques, valid measurement in thermography requires following strict methodological steps from data acquisition to analyses and interpretation. In this chapter, we discuss the methodological aspects that must be taken into account when acquiring thermic images, along with some practical examples and recommendations based on the current literature.

Plantar pressure and foot temperature responses to acute barefoot and shod running

AbstractPurpose. Increased contact pressure and skin friction may lead to higher skin temperature. Here, we hypothesized a relationship between plantar pressure and foot temperature. To elicit different conditions of stress to the foot, participants performed running trials of barefoot and shod running. Methods. Eighteen male recreational runners ran shod and barefoot at a self-selected speed for 15 min over different days. Before and immediately after running, plantar pressure during standing (via a pressure mapping system) and skin temperature (using thermography) were recorded. Results. No significant changes were found in plantar pressure after barefoot or shod conditions (p > 0.9). …

Effects of 24 h Compression Interventions with Different Garments on Recovery Markers during Running

Compression and temperature manipulation are discussed as strategies to improve performance markers and recovery in sports. Here, we investigate the effects of compression stockings made with fabric, either combined or not with heating and cooling substances, on variables related to running performance and recovery. Ten trained runners (mean ± standard deviation age 45 ± 9 years old, body mass 69 ± 7 kg, height 166 ± 4 cm) with no experience of using compression garments performed an intense running session of 10 km, then wore a stocking for 24 h (randomized

A preliminary investigation about the observation of regional skin temperatures following cumulative training loads in triathletes during training camp.

There are controversial results in the literature concerning the concept that cumulative training load could affect basal skin temperature in the days following training sessions. The objective was to measure skin temperature in triathletes during a training camp with cumulative training load. Ten male recreational triathletes involved in a training camp underwent measurements of perception of pain and fatigue (visual analogue scale), skin temperature (infrared thermography), and jump performance (counter movement jump test) before, one day, and two days after the beginning of the training camp. All measurements were performed before the breakfast. Jump height did not differ between the day…

Understanding the effect of window length and overlap for assessing sEMG in dynamic fatiguing contractions: A non-linear dimensionality reduction and clustering

The Short-Time Fourier transform (STFT) is a helpful tool to identify muscle fatigue with clinical and sports applications. However, the choice of STFT parameters may affect the estimation of myoelectrical manifestations of fatigue. Here, we determine the effect of window length and overlap selections on the frequency slope and the coefficient of variation from EMG spectrum features in fatiguing contractions. We also determine whether STFT parameters affect the relationship between frequency slopes and task failure. Eighty-eight healthy adult men performed one-leg heel-rise until exhaustion. A factorial design with a window length of 50, 100, 250, 500, and 1000 ms with 0, 25, 50, 75, and 90…

Effects of asymmetrical exercise demands on the symmetry of skin temperature in archers

Abstract Objective: To analyse skin temperature asymmetries in response to asymmetrical exercise demand in archers. Approach: The skin temperature of the trunk and upper limbs was measured in 30 archers with an infrared camera at three different moments: before (Pre), immediately after (Post), and 10 min after (Post10) a simulated competition (18 warm-up shots and 72 qualifying round shots). Relative and absolute asymmetries were determined. Stepwise multiple linear regressions were performed using the variations of relative and absolute skin temperature asymmetries as predicting variables, and sex, age, experience, body mass index, bow mass, bow power, and rate of perceived exertion of com…

Spectral properties of muscle activation during incremental cycling test

It is uncertain whether fatigue and workload would affect muscle recruitment during cycling. To infer on changes in priority for recruitment of motor units, we assessed the combined effects of fatigue and workload during an incremental cycling test to exhaustion on frequency components of lower limbs muscle activation. Competitive cyclists performed an incremental maximal cycling test while muscle activations were recorded from the right and left vastus lateralis, biceps femoris and gastrocnemius medialis. Muscle activation signals were assessed using frequency band analyses and decomposed into overall, high and low frequency bands. Combined effects from workload/fatigue were assessed using…

Association between physiological stress and skin temperature response after a half marathon

OBJECTIVE: The objective of this study was to determine the association between skin temperature response and the physiological stress after a half marathon. APPROACH: Seventeen runners were measured 48 h before, 24 h before, 24 h after and 48 h after completing a half marathon. The measurements on each day of testing included blood markers (creatine kinase [CK] and glutamate oxaloacetate transaminase [GOT]), perception of pain and fatigue (using a visual analogue scale), skin temperature (using infrared thermography), and jump performance (using countermovement jump test). MAIN RESULTS: CK (p     1.0) increased 24 h after the half marathon, whereas jump performance decreased (p   <  0.01 a…

Effect of saddle height on skin temperature measured in different days of cycling

Infrared thermography can be useful to explore the effects of exercise on neuromuscular function. During cycling, it could be used to investigate the effects of saddle height on thermoregulation. The aim of this study was to examine whether different cycling postures, elicited by different knee flexion angles, could influence skin temperature. Furthermore, we also determined whether the reproducibility of thermal measurements in response to cycling differed in the body regions affected or not affected by saddle height. Sixteen cyclists participated in three tests of 45 min of cycling at their individual 50 % peak power output. Each test was performed in a different knee flexion position on …

Effects of workload level on muscle recruitment in cycling

AbstractPurpose. Despite the volume of studies addressing muscle activation during pedaling, it is unclear whether changes in workload level during cycling could dictate motor unit recruitment. The present study investigated the frequency content of lower limb muscle activation during submaximal workloads. Methods. Twelve male competitive cyclists pedaled at three workload levels: (1) maximum aerobic power output (PO