The Science Behind Whether Late-Night Workouts Affect Sleep

Will it affect your sleep when you work out during the day or evening? The short answer is yes. More than 80% of people who exercise (day or night) tend to sleep better than those who do not exercise, according to a poll by the National Sleep Foundation. So when in doubt, if you are having a tough time sleeping, get some exercise during the day and see whether it helps.

 However, does it matter when you exercise? Here is a question from a young man asking a fairly common question with an answer that is not so common.

Stew

Thanks for the help! Is it bad for you to exercise before bed? Also, does it matter when you exercise? Like the same time every day or so? Or just that you exercise? Like, say I ran a couple of miles before bed, then in the morning did strength workouts? Is that bad? Thanks -- Aaron

Aaron -- great question. Here are several answers to your question as it depends on what works best for you in the long run. Sometimes, you have to figure out what time you train, what program to do and what consistency works best for you. We are all different and respond differently to the various options available to us.

What the Science Says

According to an exercise and sleep study done by the European Sleep Study Society, exercising a few hours before bed had no effect on the quality of sleep.

WebMD notes: Anecdotal evidence cautions some people to avoid late-night training sessions. However, if you give yourself three hours to calm down, reduce your body temperature, shower and relax, a late-night cardio or lifting session has little to no effect on your sleep patterns, as mentioned in the study above.

But, it depends on the person. If you are a morning person and are typically more energized in the morning, a late-night workout may keep you awake longer than a night person. A night person who is most productive between the hours of 10 p.m. and 2 a.m. may feel little effect with a midnight run or resistance training session. 

It may even help them relax more and get to sleep faster. Of course, it also depends on when you have to be awake in the morning. Getting less than six hours of sleep will start to affect everyone negatively, regardless of whether they are a morning or night person.

My Personal Experience

Some people have difficulty falling asleep after late-night workouts. I worked out before school when I was young and work out before going to work these days. I am a morning person and always have been. The only time I exercise late in the evening is when I do not want to go to sleep and have to be awake for 3-4 more hours. 

This is a lesson learned after spending a few hours in bed, just looking at the ceiling after an evening workout. Often, my most productive time in the day is immediately after a workout (before noon). However, after an early evening workout, I can match the high-morning productivity in the evening. I am wide awake, adrenaline is pumping, and my heart rate and body temperature have increased.

Sorry for the multiple answers. Science is right, but so is what affects you personally. This is not much different than a diet plan. Find a plan that works for you, that you enjoy doing, and where you see results. 

Otherwise, it does not matter what a study says or what I say. Find out what is best for you. You will learn what makes you perform optimally with some trial and error.

Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to stew@stewsmith.com.

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