Many people are unsure when the best time is to exercise for better sleep. We caught up with our sleep science expert, Dr Dale Rae, about the effect of exercise on sleep, and when the best time to work out is.
When is the best time to exercise for better sleep?
The short answer is that “It depends!” As humans we all differ with respect to when we like to wake up in the morning, when we like to go to sleep at night, and how long we prefer to sleep for. These differences are mainly driven by our body’s 24h (circadian) clock. Your clock may be that of a “morning type” or early bird. If that is the case you may notice that you wake easily around sunrise, but feel the need to crawl into bed well before midnight. If your clock is that of an “evening type” or night owl, you will probably resent early morning alarm clocks, preferring wake-up times closer to 08h00 or 09h00, and find that you are at you best in the evenings and at night, often only turning in around or after midnight. Similarly, some people have long sleep needs – without 8 or 9 hours of sleep each night they feel wrecked during the day. For other people, the natural “short sleepers”, as little as 5 or 6 hours each night is all they need to reboot.
How does exercise affect sleep?
So how does sleep relate to exercise? Exercise is an important consideration for sleep quality. Quite simply, being more active during the day by including both planned and incidental exercise has been shown to improve sleep quality – that is, how deeply you sleep, how soundly you sleep (fewer disturbances) and how refreshed you feel upon waking. So if you are currently sleeping poorly and not exercising, consider making a little time on most days for exercise – there is a good chance that this will help improve your sleep.
Timing your exercise for better sleep
The timing of your exercise session is important too, as exercise has an “alerting” effect on your body. You may have noticed that after a training session you feel energised, hungry or more mentally alert. In this state, it is very difficult to fall asleep. In fact, most of us need at least 1-2 hours to come down off our exercise high.
This is where we need to consider our personal body clock.
For the early birds:
Early birds are usually able to squeeze in a training session before work since they naturally wake early. This is a great strategy to make the most of their peppy morning attitude, and leaves their evenings free for an easy wind-down ahead of an early bed time. Should early birds slot in an evening exercise session (e.g. 18h00 or 19h00), they may notice that they feel too revved up to fall asleep at their usual time – especially if they still need to eat after training. The result is a later-than-usual bed time, and they run the risk of not getting enough sleep that night as their body clock will almost certainly have them up and going at sunrise. Do this too often and they will more than likely begin to accumulate sleep debt.
For the night owls:
Early morning exercise sessions for night owls may not be a great idea. First, owls are less likely to feel like exercising in the morning as their bodies take significantly more time to get primed for the day. Second, since owls usually have late bed times, early morning training will most likely reduce their sleep time, allowing them to accumulate sleep debt. Exercising in the late afternoons or evenings often suits owls well. Their bodies are purring by then, and winding down for sleep is not even a consideration yet. Finishing a training session at say 20h00 is certainly no train smash for owls, since they still have a good 4 or 5 hours to wind down before bed time.
Work with your own body clock
To work out when it’s best to exercise for better sleep, the rules are simple – work with your body! If you are an early bird, opt for morning, midday or early afternoon training sessions. Night owls will almost certainly benefit from midday or afternoon / evening training sessions. The trick is to fit in your exercise at a time that still allows you to get the precious sleep you need.
For any further support with sleep concerns you can also contact us at Sleep Science email@example.com.
By Dr Dale Rae
Sleep Scientist, The Sports Science Institute of SA