0000000000699869
AUTHOR
D. Callard
Nycthemeral variations in core temperature and heart rate: continuous cycling exercise versus continuous rest.
Circadian rhythms have formed the subject of many researches in man during bed rest or usual routine, but have been little studied during continuous and sustained physical exercise. This study deals with the influence of time of day on biological markers in competitive cyclists during continuous physical exercise versus continuous rest. Ultra-distance cyclists were studied over a 24 h period (13:00 to 13:00 h the next day) in the laboratory. The subjects were requested to maintain a constant speed (set at 65% - 70% of their maximal aerobic speed obtained during a preliminary test) on their own bicycles which were equipped with home trainers. Workload, core temperature and heart rate were mo…
Fluctuations nycthémérales des capacités musculaires chez l’homme sportif : avec sommeil versus en privation de sommeil
L’objectif de ce travail a consiste, a partir d’une partie des resultats de deux etudes differentes, a estimer les effets de la privation de sommeil sur les fluctuations circadiennes du fonctionnement du systeme musculo-squelettique. Dans chacune des etudes (EAS et EPS ), les moments musculaires isometriques maximaux et les activites electromyographiques des muscles impliques ont ete enregistres a sept reprises au cours du nycthemere a l’aide d’un ergometre isocinetique : contractions volontaires breves de flexion du coude pour EAS dont les sujets ont dormi a des horaires standardises, et d’extension de la jambe pour EPS dont les sujets ont ete completement prives de sommeil. Les resultats …
Circadian rhythms in human muscular efficiency: continuous physical exercise versus continuous rest. A crossover study.
This study deals with the influence of time of day on neuromuscular efficiency in competitive cyclists during continuous exercise versus continuous rest. Knee extension torque was measured in ultradistance cyclists over a 24h period (13:00 to 13:00 the next day) in the laboratory. The subjects were requested to maintain a constant speed (set at 70% of their maximal aerobic speed obtained during a preliminary test) on their own bicycles, which were equipped with cyclosimulators. Every 4h, torque developed and myoelectric activity were estimated during maximal isometric voluntary contractions of knee extensors using an isokinetic dynamometer. Mesenteric temperature was monitored by telemetry.…