Sleep and exercise are two concepts that, pending on the quality experienced by an individual, can be greatly impactful on many other physiological processes within our bodies.
When it comes to timings of exercise in relation to our sleep, current recommendations advise against exercising as it may have adverse effects on sleep.
However, is this true?
A Systematic Review, out of the Federal Institute of Technology in Zurich, Switzerland within the Human Movement Sciences and Sport department, was performed to investigate the extent to which exercise before sleep has on its quality. The variables of exercise intensity and overall duration were also targeted to see whether they would modify the outcome.
The result of their review of 11, 717, with 23 being included found the opposite of what many recommendations had previously found. General exercise, light to moderate, before sleep was associated with overall greater amount of slow wave sleep (N3) by 1.3%. However, when discussions of high/vigorous intensity exercise were established, this was shown to impair sleep-onset latency, total sleep time and overall sleep efficiency with any high intensity exercise ending 1 hour or less before attempting sleep.
The main takeaway to gather from this study is whilst exercise is not something to necessary avoid before bed, in fact a light walk/jog or moderate resistance training session may be positive in granting greater amount of deeper sleep. However, if sleep is already a concern, avoiding high/vigorous intensity late night resistance or aerobic training that brings your heart rate to 70-85% of your maximum heart rate (208- 0.7x age).
IF an individual is so inclined to the late-night high intensity training, incorporating a post-exercise routine that raises the time between exercise and overall bedtime. An example could be the use of a light meal and a relaxing bath/shower, of which both have their sleep benefits, to negate those of vigorous exercise may be best.
Reference:
Stutz, J., Eiholzer, R., & Spengler, C. M. (2019). Effects of Evening Exercise on Sleep in Healthy Participants: A Systematic Review and Meta-Analysis. Sports medicine (Auckland, N.Z.), 49(2), 269–287. https://doi.org/10.1007/s40279-018-1015-0
