Search results for "performance"
showing 10 items of 4457 documents
Glucosamine Supplementation Improves Physical Performance in Trained Mice
2021
Introduction D-Glucosamine (GlcN) is one of the most widely consumed dietary supplements and complementary medicines in the world and has been traditionally used to attenuate osteoarthritis in humans. GlcN extends lifespan in different animal models. In humans, its supplementation has been strongly associated with decreased total mortality and improved vascular endothelial function. GlcN acts as a suppressor of inflammation and by inhibiting glycolysis, it can activate the metabolism of stored fat and mitochondrial respiration. Methods The conventional human GlcN dose is 1,500 mg x day-1 but extensive evidence indicates that much higher doses are well tolerated. GlcN is one of the supplemen…
Analysis of elite swimmers' activity during an instrumented protocol
2009
The aim of this study was to examine swimmers' activity-technical device coupling during an experimental protocol (MADsystem). The study was conducted within a course-of-action theoretical and methodological framework. Two types of data were collected: (a) video recordings and (b) verbalizations during post-protocol interviews. The data were processed in two steps: (a) reconstruction of each swimmer's course of action and (b) comparison of the courses of action. Analysis from the actors' point of view allowed a description of swimmer-technical device coupling. The results showed that the technical device modified the athletes' range of perceptions and repertoire of actions. They also indica…
Strength and Power Testing of Athletes: A Multicenter Study of Test-Retest Reliability.
2022
Author's accepted manuscript Accepted author manuscript version reprinted, by permission, from International Journal of Sports Physiology and Performance (IJSPP), 2022, 17 (7): 1103-1110, https://doi.org/10.1123/ijspp.2021-0558. © Human Kinetics, Inc. Purpose:This study examined the test–retest reliability of common assessments for measuring strength and power of the lowerbody in high-performing athletes.Methods:A total of 100 participants, including both male (n=83) and female (n=17) athletes(21 [4] y, 182 [9] cm, and 78 [12] kg), were recruited for this study, using a multicenter approach. The participants underwentphysical testing 4 times. Thefirst 2 sessions (1 and 2) were separated by∼…
Mean power during 20 sec all-out test to predict 2000-m rowing ergometer performance in national level young rowers
2014
Aim. The aim of this study was to assess the relationship between mean power during 20-s all-out rowing ergometer test and 2000-m rowing ergometer performance, in 20 young male rowers (mean age 15.2 ± 1.3 years). Methods. Mean power during 20-s all-out test (W20), maximal oxygen uptake during incremental test (VO2max), and anthropometric values, were measured and correlated with the time to perform a 2000-m trial (t2000). Results. W20 showed the highest correlation with t2000 (r = -0.947, P < 0.0001). Stepwise multiple linear regression analysis showed that W20, VO2max, and fat-free mass, were the variables most correlated with t2000, accounting for 95.1% of the variance, and that 89.7% …
Got rhythm… for better and for worse. Cross-modal effects of auditory rhythm on visual word recognition
2013
The present research aimed to investigate whether, as previously observed with pictures, background auditory rhythm would also influence visual word recognition. In a lexical decision task, participants were presented with bisyllabic visual words, segmented into two successive groups of letters, while an irrelevant strongly metric auditory sequence was played in a loop. The first group of letters could either be congruent with the syllabic division of the word (e.g. val in val/se) or not (e.g. va in va/lse). In agreement with the Dynamic Attending Theory (DAT), our results confirmed that the presentation of the correct first syllable on-beat (i.e. in synchrony with a peak of covert attentio…
Evidence of beat perception via purely tactile stimulation
2008
Humans can easily tap in synchrony with an auditory beat but not with an equivalent visual rhythmic sequence, suggesting that the sensation of meter (i.e. of an underlying regular pulse) may be inherently auditory. We assessed whether the perception of meter could also be felt with tactile sensory inputs. We found that, when participants were presented with identical rhythmic sequences filled with either short tones or hand stimulations, they could more efficiently tap in synchrony with strongly rather than weakly metric sequences. These observations suggest that non-musician adults can extract the metric structure of purely tactile rhythms and use it to tap regularly with the beat induced …
Honeybees produce millimolar concentrations of non-neuronal acetylcholine for breeding: possible adverse effects of neonicotinoids
2016
The worldwide use of neonicotinoid pesticides has caused concern on account of their involvement in the decline of bee populations, which are key pollinators in most ecosystems. Here we describe a role of non-neuronal acetylcholine (ACh) for breeding of Apis mellifera carnica and a so far unknown effect of neonicotinoids on non-target insects. Royal jelly or larval food are produced by the hypopharyngeal gland of nursing bees and contain unusually high ACh concentrations (4–8 mM). ACh is extremely well conserved in royal jelly or brood food because of the acidic pH of 4.0. This condition protects ACh from degradation thus ensuring delivery of intact ACh to larvae. Raising the pH to ≥5.5 and…
Long-term strength and balance training in prevention of decline in muscle strength and mobility in older adults
2018
Background. Reductions in muscle strength and poor balance may lead to mobility limitations in older age. Aims. We assessed the effects of long-term once-weekly strength and balance training (SBT) on muscle strength and physical functioning in a community-based sample of older adults. Methods. 182 individuals [130 women and 52 men, mean age 80 (SD ± 3.9) years] underwent supervised SBT as part of the Geriatric Multidisciplinary Strategy for the Good Care of the Elderly study. Training was offered once a week for 2.3 years. Isometric knee extension and flexion strength, chair rise, maximal walking speed, timed up and go (TUG) and Berg Balance Scale (BBS) were measured at baseline, after 2-ye…
Influence of competition on performance factors in under-19 soccer players at national league level.
2020
The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defen…
Relationship between physical activity and physical performance in later life in different birth weight groups.
2017
There is strong evidence that physical activity (PA) has an influence on physical performance in later life. Also, a small body size at birth has been associated with lower physical functioning in older age and both small and high birth weight have shown to be associated with lower leisure time physical activity. However, it is unknown whether size at birth modulates the association between PA and physical performance in old age. We examined 695 individuals from the Helsinki Birth Cohort Study born in Helsinki, Finland between 1934 and 1944. At a mean age of 70.7 years PA was objectively assessed with a multisensory activity monitor and physical performance with the Senior Fitness Test (SFT…