81 research outputs found
Effects of Time of Day and Sleep Deprivation on Motorcycle-Driving Performance
The aim of this study was to investigate whether motorcycle handling capabilities – measured by means of the efficiency of emergency manoeuvres – were dependent on prior sleep deprivation and time of day. Twelve male participants voluntarily took part in four test sessions, starting at 6 a.m., 10 a.m., 2 p.m., and 6 p.m., following a night either with or without sleep. Each test session comprised temperature and sleepiness measurements, before three different types of motorcycling tests were initiated: (1) stability in straight ahead riding at low speed (in “slow motion” mode and in “brakes and clutch” mode), (2) emergency braking and (3) crash avoidance tasks performed at 20 kph and 40 kph. The results indicate that motorcycle control at low speed depends on time of day, with an improvement in performance throughout the day. Emergency braking performance is affected at both speeds by time of day, with poorer performance (longer total stopping distance, reaction time and braking distance) in the morning, and also by sleep deprivation, from measurements obtained at 40 kph (incorrect initial speed). Except for a tendency observed after the sleepless night to deviate from the initial speed, it seems that crash avoidance capabilities are quite unaffected by the two disturbance factors. Consequently, some motorcycle handling capabilities (stability at low speed and emergency braking) change in the same way as the diurnal fluctuation observed in body temperature and sleepiness, whereas for others (crash avoidance) the participants were able to maintain their initial performance level despite the high levels of sleepiness recorded after a sleepless night. Motorcycle riders have to be aware that their handling capabilities are limited in the early morning and/or after sleep deprivation. Both these situations can increase the risk of falls and of being involved in a road accident
Alternance activité-repos, sommeil et récupération
Davenne Damien. Alternance activité-repos, sommeil et récupération. In: Les Cahiers de l'INSEP, n°27, 2000. Sport de haut niveau et récupération. pp. 99-112
Modifications des rythmes circadiens chez la personne âgée par l'activité physique (évaluation de ces effets sur le rythme de la température, le rythme veille/sommeil et les performances diurnes en conduite automobile simulée)
CAEN-BU Sciences et STAPS (141182103) / SudocORSAY-PARIS11-Bib. STAPS (914712103) / SudocSudocFranceF
Etude des fluctuations diurnes de la fatigue et de la récupération musculaire (approches mécaniques et neurophysiologiques)
CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF
Rythmicité circadienne des performances anaérobies et facteurs de perturbation
CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF
Davenne D. Relationships between sleep, physical activity and human health. Physiol Behav
Abstract Although sleep and exercise may seem to be mediated by completely different physiological mechanisms, there is growing evidence for clinically important relationships between these two behaviors. It is known that passive body heating facilitates the nocturnal sleep of healthy elderly people with insomnia. This finding supports the hypothesis that changes in body temperature trigger somnogenic brain areas to initiate sleep. Nevertheless, little is known about how the core and distal thermoregulatory responses to exercise fit into this hypothesis. Such knowledge could also help in reducing sleep problems associated with nocturnal shiftwork. It is difficult to incorporate physical activity into a shiftworker's lifestyle, since it is already disrupted in terms of family commitments and eating habits. A multi-research strategy is needed to identify what the optimal amounts and timing of physical activity are for reducing shiftwork-related sleep problems. The relationships between sleep, exercise and diet are also important, given the recently reported associations between short sleep length and obesity. The cardiovascular safety of exercise timing should also be considered, since recent data suggest that the reactivity of blood pressure to a change in general physical activity is highest during the morning. This time is associated with an increased risk in general of a sudden cardiac event, but more research work is needed to separate the influences of light, posture and exercise per se on the haemodynamic responses to sleep and physical activity following sleep taken at night and during the day as a nap
Rythmicité circadienne de la fréquence de pédalage spontanée, de la cinématique du mouvement et des variables cardio-respiratoires au cours d'exercices de type aérobie
CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF
Rythmicité biologique circadienne au cours d'activités physiques soutenues et continues
Résumé françaisDIJON-BU Sciences Economie (212312102) / SudocSudocFranceF
Fluctuations diurnes de la fatigue et du geste de pédalage au cours d'un exercice de type anaérobie ( influence de la privation de sommeil)
L objectif de ce travail est d étudier les effets de l heure de la journée et de la privation de sommeil sur la performance, la fatigue et les patterns biomécaniques de pédalage au cours d un exercice de type anaérobie. Afin de répondre à cet objectif, 3 études ont été conduites. Les 2 premières études consistaient en 2 sessions de test à 06:00 et 18:00 h, au cours desquelles un test de Wingate de 60 s sur bicyclette ergométrique était effectué. Les résultats observés au cours des 2 études permettent de mettre en évidence que les modifications des paramètres biomécaniques du mouvement de pédalage et que le niveau d expertise en cyclisme détermineraient non seulement l existence des fluctuations journalières des performances mais également l amplitude de variation de ces fluctuations et le profil de fatigue au cours de la journée. L expertise augmente l influence des effets de l heure de la journée sur la performance tandis qu elle conduit à diminuer ces effets sur la fatigue. La 3ème étude comportait 3 sessions de test à 06:00 h, après une nuit normale, une nuit de privation totale de sommeil et une nuit de privation de sommeil associée à une tâche de conduite prolongée. La performance, la fatigue et les paramètres biomécaniques mesurés au cours du test de Wingate ne sont pas altérés après une nuit de privation totale de sommeil. Les mêmes résultats sont observés après une perturbation des centres supérieurs cérébraux, suggérant que le contrôle de l organisation du mouvement de pédalage impliquerait une gestion au niveau de la moëlle épinière et que le rôle du niveau de vigilance dans l existence des variations circadiennes des performances anaérobies reste discutable.The aim of this work is to study the time-of-day effects and sleep deprivation on performance, fatigue and cycling biomechanical patterns during a sustained anaerobic exercise. To answer this objective, 3 studies have been done. During the 2 first studies, subjects had 2 test sessions, one at 06:00 h and the other at 18:00 h. At each test session, subjects were asked to perform a sustained Wingate test lasting 60 s. The results show that the diurnal modifications in kinetic and kinematic parameters of cycling movement and that the level of expertise in cycling would determine the existence of diurnal fluctuations in the anaerobic performance and the range of variation of these fluctuations, and the profile of fatigue as a function of time of day. The time-of-day effects on the performance are increased while these effects on the fatigue are reduced by the level of expertise. During the 3rd study, subjects had 3 test sessions at 06:00 h the day following a normal night, a total sleep deprivation night and a total sleep deprivation night associated with extensive driving task. During the 60 s Wingate test, the performance, fatigue and cycling biomechanical parameters are not altered by a total sleep deprivation night. The same results are observed after a total sleep deprivation night associated with extensive driving task. It is hypothesized that the cycling movement organization would be controlled at rather spinal than surpraspinal level. Moreover, these results seem to indicate that the level of vigilance would not be involved in circadian variations of anaerobic performances.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF
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