This study investigated the effects of combined sleep deprivation and strenuous exercise on cognitive and neurobehavioral performance among long-distance runners completing one of the most difficult ultramarathons in the world. Seventeen runners participated. Each had a wrist-worn actigraph throughout the race to record their sleep time. In addition, each individual's performance in 10-min response-time tests before and after the race was recorded and a questionnaire enabled participants to report any difficulties they experienced during the competition. During race completion times of 27 to 44 h, combined acute lack of sleep (12 ± 17 min of rest during the race) and strenuous exercise (168.0 km) had marked adverse effects on cognitive performances ranging from mere lengthening of response time to serious symptoms such as visual hallucinations. This study suggests that regardless of rest duration and time in race, cognitive performances of ultramarathoners are adversely affected.

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Ninety-two runners completed the study during a 168 km mountain ultramarathon (MUM). Sleepiness, self-reported sleep duration, and cognitive performance were assessed the day before the race and up to eight checkpoints during the race. Sleepiness was assessed using the Karolinska Sleepiness Scale. Cognitive performance was also assessed using the Digital Symbol Substitution Task (DSST). Runner reported 23.40 ± 22.20 minutes of sleep (mean ± SD) during the race (race time: 29.38 to 46.20 hours). Sleepiness and cognitive performance decrements increased across this race, and this was modulated by time-of-day with higher sleepiness and greater performance decrements occurring during the early morning hours. Runners who slept on the course prior to testing had poorer cognitive performance, which may suggest that naps on the course were taken due to extreme exertion. This study provides evidence that cognitive performance deficits and sleepiness in MUM are sensitive to time into race and time-of-day.

Lack of sleep is known to negatively affect adolescent's health and the links between regular physical activity and sleep are unclear.This pilot study investigated whether the regular practice of physical activities among sedentary female students would improve their sleep. Nineteen female students, identified as sedentary and having poor subjective sleep quality were assigned in two groups to a 12-week university physical activities programme in accordance with the recommendations of World Health Organisation (N = 10) or to a control condition (N = 9). Sleep was assessed with actigraphy before and after the study and with the Pittsburg Sleep Quality 15 Index (PSQI) at the beginning, middle, and end of the study. The intensity of physical activities was controlled by heart rate monitor. The analysis showed that sleep quality in the physical activities group improved, with the mean ± SD PSQI score decreasing from 9.1 ± 1.7 to 4.8 ± 2.0. Despite some limitations, these pilot data indicate that a physical activities programme is feasible to implement in students, and that participation in such a programme improves sleep in 18- 24 -year-old female adolescents. Further potential benefits remain to be investigated in follow-up research.