Exploring the Benefits-Packed Relationship Between Sleep and Exercise with Dr. Shona Halson

By: Shona Halson, PhD  |  September 22nd, 2021

Some of the world’s best athletes are often quoted saying they regularly get 10 or even 12 hours of sleep each night. While that may seem a really long night’s sleep for most of us, it is worth considering why athletes devote so much of each 24 hours to sleep. It is generally well accepted that sleep is the best option for our body and brain to recover after exercise. However, this relationship also works both ways- regular exercise can also be incredibly beneficial for getting a good night’s sleep. 

Why sleep is so important for recovery from exercise? 

Exercise is one of the best things we can do for our physical and mental health. However, when we exercise, we use fuels, which can breakdown some muscle tissue and may generate fatigue. This ‘breakdown’ is part of the process of getting fitter and stronger, but we need to have a balance with good recovery. Sleep is one of the very best ways to recover from exercise.  

Sleep enhances recovery from exercise by repairing and rebuilding muscle, optimizing hormone release, reducing inflammation, restoring energy and refreshing the brain. Adequate sleep also helps us feel good, reduces fatigue and makes us more motivated to exercise. 

What happens to physical performance when we are sleep deprived? 

Some of the reasons we know sleep is so important for recovery is due to the negative effects of sleep deprivation on physical and mental performance. From a physical perspective, it is often possible to still perform at a relatively high level after 3-4 days of poor sleep. However, one of the most critical things that occur when we are sleep deprived is that the perception of how hard the exercise feels increases. We are also more likely to have a slower reaction time and make more mistakes and errors. Indicators of damaged muscle measured in the blood increases and ‘breakdown’ hormones may increase. If sleep deprivation continues, then physical performance will likely decrease and the risk of excessive fatigue, illness and injury may increase. 

What are the benefits of exercising regularly on sleep?  

There are so many benefits of exercise for physical and mental health that it is not possible to name them all. Sleep is one of these aspects of health that is improved via regular exercise. Generally, research suggests that exercise shortens the time it takes to fall asleep and results in deeper or improved quality sleep. 

How does exercise improve sleep? 

The specific reasons for why exercise has been shown to be so good for sleep are slightly unclear. However, scientists believe it may be due to several reasons. These include: reduced anxiety, anti-depressant effects and weight loss. Of course, exercise has benefits on other aspects of health and wellbeing such as quality of life and reducing pain. It’s always good to remember that exercise is indeed medicine.  

What time, type, and duration of exercise is best to improve sleep? 

Exercise is great to set your circadian rhythm. And morning exercise with sunlight exposure is great for optimizing sleep at night. While it is often suggested that we should avoid high intensity exercise in the 4 hours before bedtime, we now know that this window may be reduced to around 1-2 hours before bed.   

A recent analysis of 15 published papers, with a total of 194 participants found that early evening high intensity exercise completed up to 2 hours before bedtime may benefit sleep that night. High intensity exercise completed between 2-4 hours before bed may actually shorten how long it takes to fall asleep and increase the quality of sleep during the night. Further, sleep was more positively influenced when the exercise activity was longer, between 30-60min, when compared to a shorter duration. It’s worth noting that later evening exercise, within one hour of bedtime, may disturb your nighttime sleep and should be avoided. 

New research also suggests that weight training can be beneficial for sleep, not just endurance or aerobic exercise. So, for those who cannot run or cycle or who prefer to lift weights, this is also a good option. There have also been reported benefits of yoga or Pilates on sleep, so the exercise itself does not need to be overly strenuous. Regardless of type of exercise chosen, research supports that a standard 30-60minute workout is an ideal duration to benefit sleep. However, the best form of exercise is the activities that you will do regularly and that you enjoy most. 

Can exercise be bad for sleep? 

Exercise can have a detrimental effect on sleep quality if an individual pushes themselves too hard over a long period of time with minimal recovery. Athletes who are overtrained have disturbed sleep quality, so it’s important to balance the training and recovery and always listen to your body. Rest days are important for adapting and decreasing the risk of overtraining, illness and injury. 

Should I prioritize sleep or exercise or both? 

In an ideal world, we all would find the time for both exercise and sleep, but that isn’t always possible. The logical question to ask next is if I am pressed for time and have to choose, should I sleep or should I exercise? If you are chronically sleep deprived and getting under 6 hours of sleep, sleep would be the priority. However, it would be worthwhile to explore ways to get sleep of sufficient duration most nights AND exercise at least 3 times per week. Protecting sleep is vital for our health and wellbeing and enhancing recovery from exercise. In turn, that exercise can result in a better night’s sleep and for most of us, that is something we really do need. 

Eat, sleep, train, repeat- it works! 

 

References: 

Effect of exercise training on improving sleep disturbances: a systematic review and meta-analysis of randomized control trials. Amiri S, Hasani J, Satkin M.Sleep Med. 2021 Aug;84:205-218. doi: 10.1016/j.sleep.2021.05.013. 
The effect of resistance exercise on sleep: A systematic review of randomized controlled trials. 
Kovacevic A, Mavros Y, Heisz JJ, Fiatarone Singh MA.Sleep Med Rev. 2018 Jun;39:52-68. doi: 10.1016/j.smrv.2017.07.002.  
The effects of evening high-intensity exercise on sleep in healthy adults: A systematic review and meta-analysis. Frimpong E, Mograss M, Zvionow T, Dang-Vu TT. Sleep Med Rev. 2021 Aug 3;60:101535. doi: 10.1016/j.smrv.2021.101535. 
How does sleep help recovery from exercise-induced muscle injuries? Chennaoui M, Vanneau T, Trignol A, Arnal P, Gomez-Merino D, Baudot C, Perez J, Pochettino S, Eirale C, Chalabi H.J Sci Med Sport. 2021 May 18:S1440-2440(21)00132-8. doi: 10.1016/j.jsams.2021.05.007. 

About the Author: 

Professor Shona Halson is from ACU’s School of Behavioural and Health Sciences and prior to this was the Head Recovery Physiologist at the Australian Institute of Sport for over 15 years and has been a part of three Olympic campaigns with the Australian Olympic Committee. Her research focuses on sleep, recovery and fatigue and she has published over 140 peer-reviewed articles and multiple book chapters. Shona is an Associate Editor for the International Journal of Sports Physiology and Performance and also provides consultancy services to the Australian Open Tennis Tournament and Nike as part of both the Nike Performance Council and Nike Sports Research Advisory Group. Shona also consults to a number of national and international professional sporting teams.  


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