Practicing 30 minutes of vigorous exercise (55-65% of VO2 max), 3 to 4 hours before bedtime, improves the quality of deep sleep, particularly in sedentary individuals.

noli's read

This advice is based on research examining the relationship between physical activity and sleep architecture. The idea that exercise promotes deep sleep (slow-wave sleep) is supported by several studies, notably systematic reviews such as the one published in Sleep Medicine Reviews (meta-analysis), which confirm a moderate but real positive effect. The temporal specificity (3-4 hours before bedtime) is a cautious recommendation: while intense exercise increases body temperature and alertness immediately after exertion, these effects generally fade sufficiently to allow for better thermal recovery afterward. The focus on sedentary individuals is relevant, as it is in this group that the benefits for circadian regulation and sleep pressure are most pronounced. However, the claim may be perceived as exaggerated if applied universally, because individual response to late-day exercise varies enormously: in some, it may delay sleep onset due to excessive stimulation of the sympathetic nervous system. There is no evidence that this protocol works the same way for all chronotypes.

the sources

1. 1Milanović Z, Sporiš G, Weston M 2015
2. 2Lan L, Tsuzuki K, Liu YF, Lian ZW. 2017
3. 3Brown TM et al. 2022