Researchers from the University of Basel in Switzerland investigated the association between regular vigorous exercise, sleep, and psychological functioning in adolescents. The investigators hypothesized that adolescent athletes would show favorable sleep patterns and better scores for psychological functioning compared with non-athlete controls. Adolescent athletes were elite athletes recruited from “Swiss Olympic Classes.” Controls were recruited from area high schools. All study participants completed a battery of standardized psychological questionnaires to identify depression, acute/chronic anxiety, stress, and sleep-related personality traits. The results from the questionnaires were summarized as “psychological functioning.” High functioning indicated low depressive and anxiety symptoms, low everyday stress, and favorable personality traits. Participants also kept a seven-day log of sleep (Pittsburg Sleep Quality Index1) and a log of amount of exercise (hours).
A total of 434 high school students (mean age = 17.2 years) took part; 258 were athletes and 139 (58.8%) of these were female. There were 176 control students of whom 72.7% were female. The athletes reported exercising 17.69 hours per week and the controls 4.69 hours. There was no difference in total sleep time between the athlete and non-athlete groups but compared with controls, athletes had shortened sleep latency, fewer awakenings, and better concentration during the day. They also had higher scores for mood, sleep quality, and restorative sleep. Compared to controls, athletes had favorable scores on all dimensions of sleep-related personality traits. Male controls had the poorest sleep patterns while sleep patterns among female athletes did not differ from female controls.
The authors conclude that chronic, vigorous exercise is related to favorable sleep patterns and overall better psychological functioning. Males who exercise less may be at particular risk for poor sleep.
Exercise has many benefits including protection against depression and anxiety, and improvement of self-esteem.2–4 Poor sleep clearly has negative consequences (see AAP Grand Rounds, May 2010;23:595). Although it has been suggested that exercise prevents daytime sleepiness, helps stabilize circadian rhythms, and enhances slow-wave sleep,6 there is little beyond anecdotal evidence to support the common assumption that exercise improves sleep. This is particularly true in pediatrics, making this research most welcome, if not overdue. The current study did not include any objective measure of time spent exercising, but it seems unlikely either group would underestimate their efforts. Even the non-athletes in this study reported nearly five hours of exercise per week – probably far more than the typical US non-athlete high school student, although less than the 60 minutes per day recommended by the CDC.7 So, if anything, one might expect a more dramatic difference among US children.
Although the outcomes of this study are modest, the results add support for the...