Exercise training could help individuals in the military maintain function despite a lack of regular sleep.
Dr. Fabien Sauvet
While the impact between sleep and cognitive function is obvious, exercise training programs could help improve function for those deprived of sleep.
A team, led by Fabien Sauvet, MD, University of Paris, investigated the effects of 7 weeks of moderate and high-intensity interval exercise training on vigilance and sustained attention, inhibition processes and working memory during 40 hours of total sleep deprivation.
Exercise training is known to improve learning and memory and protect against the negative impact of sleep deprivation.
In the study, 16 subjects were evaluated at baseline, during the total sleep deprivation, and the day after a night of recovery sleep. The polysomnographic variables comprised of 6 electroencephalograms, 2 electrocardiograms, 2 electrooculograms, and 2 electromyogram derivations.
Each participants was prohibited from exercise, caffeine, tobacco, alcohol, and other psychoactive substances for the duration of the study, as well as 24 hours prior to beginning the study. Meals and caloric intake were also standardized for all subjects.
The exercise training program included 3 training sessions per week over a seven-week training period on an ergocycle. All 16 participants performed the entire protocol, where maximal oxygen consumption and maximal aerobic power increased after 7 weeks of exercise training (42.8 ± 1.8 vs 47.7 ± 1.7 mL/min/kg, P <0.001; 236 ± 43 vs 266 ± 38 W, P <0.001).
There was no effect on exercise training observed on resting heart rate (77.5 ± 3.2 vs 77.5 ± 3.2 bpm) and maximal heart rate (196.4 ± 2.3 vs 193.5 ± 1.7 bpm) during the cycling exercise test. The investigators found that exercise training significantly decreased errors and increased speed assessed by the psychomotor vigilance task during total sleep deprivation and recovery sleep. They found no differences in executive inhibition and working memory performances.
The multiple sleep latency test results were higher during baseline assessments, as well as during recovery sleep at post-exercise training. They also saw no difference in subjective sleepiness and daytime microsleeps over the 40-hour sleep deprivation period.
The psychomotor vigilance task speed was also positively correlated with maximal oxygen consumption and maximal aerobic power that was measured prior to the patient’s entry into the in-laboratory total sleep deprivation protocol, as well as stage 3 sleep duration measured during the first night in the total sleep deprivation protocol.
The investigators found the exercise training effects during the night recovery resulted in lower stage-3 sleep and higher rapid eye movement sleep duration. This effect was also discovered on free insulin-like growth factor I levels with lower levels during total sleep deprivation at post-exercise training.
“In healthy young men, exercise training reduced sleep pressure at baseline and protected against sustained attention deficits induced by [total sleep deprivation] with persistent effect after 1 night of recovery sleep. Nevertheless, exercise training was not effective in reducing deficits in executive inhibition and working memory induced by [total sleep deprivation],” the authors wrote.
How individuals respond to sleep deprivation is particularly important in military operations, healthcare, aviation, and other professions that require high cognitive performance during prolonged periods of awakening.
Both acute total sleep deprivation and chronic sleep restriction impair the ability to maintain wakefulness, increase subjective sleepiness, sleep propensity, and reduce various aspects of cognitive performance.
The study, “Beneficial effects of exercise training on cognitive performances during total sleep deprivation in healthy subjects,” was published online in Sleep Medicine.