Exercise, Sleep and Your Health

A TikTok video recently went viral of an expert claiming no one should exercise in the morning because they should be prioritizing sleep. Is this true? How important is sleep when it comes to athletic performance? Marc P. Kai, M.D., Ph.D., a primary care doctor with Mercy Family Care Physicians in Baltimore, recently addressed these issues for the Sleepopolis website.

While sleep is important, it's just as easy to go to bed earlier if you want to work out in the morning. When you work out isn't as important as getting a workout in; the best time is when you can. We know exercise is healthy, and reduces risk for a whole host of diseases and ailments including heart and gut health, along with your immune system. While there are advantages to working out in the morning versus later in the day, whatever fits your schedule and habits is ultimately best. I would caution that simply "sleeping in" is not the answer, rather setting up a regular bed- and wake-up times so you get enough sleep consistently is far more important than when you work out.

I don't believe in a prioritization of exercise versus sleep, rather, it's important to maintain both for a healthy lifestyle. The average person needs seven to nine hours of sleep, and though I know life gets in the way and people often have obligations that supersede exercise time, the average person also has five hours of free time per day. So, there's almost always time for at least a brisk walk if you're unable to fit in strength or cardio training.

There are advantages to both morning and evening workouts. Contrary to recent advice, morning workouts actually promote deep sleep. Your body's natural hormones peak in the morning, and stimulating your body is both natural and in-line with this natural rhythm. It also prompts your body to release melatonin, the natural circadian rhythm messenger in your body, at an appropriate time. This also means for some people exercising at night is disruptive for sleep, as it can boost those hormone levels above normal and delay melatonin release, making it harder to fall asleep. When you get after it early, you're also less likely to skip a workout, as the demands and stress of the day can take their toll and make it harder to find motivation. That's not to say evening workouts are a no-no. Some people are more motivated, or find group exercise more accessible later in the day. It may also be easier to fit in an evening workout with your work or family schedule. And having a good bedtime routine (no screen time or food within a couple hours of bedtime, calming atmosphere and activities at night), can often counteract the "upper" of working out in the evening. Again, ultimately the most important time to work out is when you can, so that you do.

Athletes at any level and any sport benefit from quality sleep. The most important part of sleep hygiene is consistency and quantity, getting the right seven to nine hours per night (this can vary person to person) is vital to muscle growth, recovery, immune health, and focus. What the studies find is athletes don't necessarily need more sleep, but the deleterious effects of sleep inadequacy are more pronounced in athletes.

As mentioned, sleep is crucial for performance, and more so in athletes where the demands from muscle breakdown/stress, nervous system activation, and mental focus are often much higher. Not giving the body enough time to normalize hormone levels (cortisol), repair damage, regulate blood sugars and insulin release, and de-stress the nervous system (REM-sleep in particular) can definitely limit gains and performance. The best studies are in endurance athletes, as glycogen (complex sugar energy stores) are spent in muscles; but this translates to elite athletes in general so the benefits are the same.

Napping is very in vogue lately, in no small part due to pandemic life. The evidence is mixed in athlete studies, but one thing is for certain: there is almost always benefit to supplementing a healthy sleep pattern with naps, and most elite athletes nap regularly. Interesting tidbit: one of the better studies suggests that athletes do not necessarily need more sleep (restorative or dysregulative reasons such as poor sleep or exercise, respectively), but rather their naps are appetitive (it's enjoyable and they feel like they perform better).

As you can imagine from above, napping is and should be considered normal for athletes. But to again underscore the bigger theme here: good sleep hygiene at night (or whenever work dictates bedtime) is paramount. If you are not getting good sleep, napping is just a band-aid.

Board Certified in Internal Medicine, Dr. Kai provides patients with diagnosis, treatment and management options for a variety of acute and chronic conditions such as high blood pressure, diabetes, asthma, osteoporosis and arthritis. He offers patients wellness exams, including annual and sports physicals, as well as immunizations and routine screenings.