Regular exercise is linked to better sleep, and a new study reveals that sleep quality is even improved when the beneficial effects are not obvious.
Experts at the University of Tsukuba have found that vigorous exercise is associated with improvement across various sleep parameters without a perceivable change in sleep quality.
Exercise is known to improve overall sleep quality by reducing the amount of time it takes to fall asleep. Physical activity also boosts the amount of time spent in deep sleep, which is the most essential stage of sleep for feeling rested and staying healthy.
However, previous studies have produced contradictory results on the link between exercise and sleep. To address these inconsistencies, the Tsukuba took a new approach. The researchers used the coefficient of variation of the envelope (CVE), a computational method for analyzing brain signals.
“CVE is a novel tool for quantifying sleep depth according to the characteristics of brain oscillations,” said study senior author Professor Kaspar E. Vogt. “We wanted to use it to determine whether exercise would improve or decrease sleep quality, in addition to determining whether short bouts of exercise could exert a lasting effect on metabolic state.”
The study was designed to evaluate the effects of 60 minutes of vigorous exercise on sleep among healthy young men.
“The results were surprising,” said the study authors. “We found that exercise improved the quality of sleep as measured using objective techniques, while the participants reported no change in the quality of their sleep.”
According to the researchers, one explanation could be that the benefits of enhanced sleep quality were countered by an increase in stress and muscle soreness, because the participants were not accustomed to vigorous exercise.
“The results of the subjective evaluations of sleep quality indicate that regular moderate exercise may be more beneficial for perceived sleep quality than occasional vigorous exercise, which might not have a subjective effect despite objective improvements in sleep,” explained Professor Vogt.
The findings indicate that sleep structure is greatly improved by exercise, and could potentially be applied in the development of new treatments for various sleep disorders.
The study is published in the journal Scientific Reports.