18 Apr The effect of exercise on sleep
Sleeping is instrumental in the recovery process, allowing for increased effectiveness and productivity throughout one’s day. In the case of physical activities, sleep is key in promoting focus, muscle growth and energy rejuvenation. This is common knowledge that most people can assume based on their own experiences. What is not thought about as often however, is the role that physical activity plays on our sleep quality. A review by Dolezal et al. (2017) observed that different forms of exercise, whether it be acute or regular, are correlated with a positive effect on sleep. The same can be said about the timing of physical activity. However, the optimal type and timing of physical activity to maximise its benefits on sleep have yet to be found.
There are a few potential pathways through which exercise improves sleep. However, these mechanisms are still being researched and their exact interactions in a human body have not been fully illuminated. As an example, Dinoff et al. (2016) observed an increase in a protein called brain-derived neurotrophic factor (BDNF) following exercise. BDNF regulates brain activity and function, and its concentration follows a circadian rhythm. Furthermore, a stu
dy by Faraguna et al. (2008) found that BDNF induced slow-wave activity in rats. Slow-wave activity is present in the brain during deep non-REM sleep. These findings combined suggests that BDNF may be an avenue through which exercise improves sleep. There are many more proteins which are being investigated that have the potential to be a part of this relationship.
So just how much of an effect does exercise have on our sleep? Baron et al. (2013) found that in a healthy population, adults who exercised for at least half an hour a day slept for 15 minutes longer than sedentary adults. King et al. (2008) found that after a 12-month study, their participants who exercised felt subjective benefits to their sleep and were also observed to spend less time in stage 1 sleep and more in stage 2 sleep when compared to controls. Hence, exercise has been found to improve subjective and objective measures of sleep. Consistent physical activity has also been found to alleviate symptoms of those suffering from various sleep conditions. For example, a review by Iftikhar, Kline & Youngstedt (2014) observed that exercise was able to reduce the severity of sleep apnea in patients with only a minimal change in body weight.
Exercise is important in keeping us healthy, not only during the waking hours of our day-to-day life, but also when we are trying to go to sleep. Though the exact mechanisms through which this occurs are not clear, evidence suggests that this relationship does exist and is significant in both healthy adults and those suffering with sleep conditions.
References
Baron, K. G., Reid, K. J., & Zee, P. C. (2013). Exercise to improve sleep in insomnia: Exploration of the bidirectional effects. Journal of Clinical Sleep Medicine, 09(08), 819–824. https://doi.org/10.5664/jcsm.2930
Dinoff, A., Herrmann, N., Swardfager, W., Liu, C. S., Sherman, C., Chan, S., & Lanctôt, K. L. (2016). The effect of exercise training on resting concentrations of peripheral brain-derived neurotrophic factor (BDNF): A meta-analysis. PLOS ONE, 11(9). https://doi.org/10.1371/journal.pone.0163037
Dolezal, B. A., Neufeld, E. V., Boland, D. M., Martin, J. L., & Cooper, C. B. (2017). Interrelationship between sleep and exercise: A systematic review. Advances in Preventive Medicine, 2017, 1–14. https://doi.org/10.1155/2017/1364387
Iftikhar, I. H., Kline, C. E., & Youngstedt, S. D. (2013). Effects of exercise training on sleep apnea: A meta-analysis. Lung, 192(1), 175–184. https://doi.org/10.1007/s00408-013-9511-3
King, A. C., Pruitt, L. A., Woo, S., Castro, C. M., Ahn, D. K., Vitiello, M. V., Woodward, S. H., & Bliwise, D. L. (2008). Effects of moderate-intensity exercise on polysomnographic and subjective sleep quality in older adults with mild to moderate sleep complaints. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 63(9), 997–1004. https://doi.org/10.1093/gerona/63.9.997
Tan, X., van Egmond, L. T., Cedernaes, J., & Benedict, C. (2020). The role of exercise-induced peripheral factors in sleep regulation. Molecular Metabolism, 42, 101096. https://doi.org/10.1016/j.molmet.2020.101096