By Dr. Mercola
One of the benefits of exercise overall is improved sleep quality, but it's typically recommended that you not exercise within three hours of bedtime so you have adequate time to wind down.
If your regular bedtime is midnight, then exercising in the evening, at 9 p.m., for instance, should theoretically not interfere with your sleep (although admittedly this schedule is pushing the limits of your body’s natural circadian rhythm).
New research is suggesting, however, that exercise as little as 1.5 hours before bed may not interfere with your sleep either and, in fact, might help you sleep better.
Strenuous Exercise at Night for Better Sleep?
The study followed 52 19-year-olds who played sports for up to 90 minutes in the evenings, ending about 1.5 hours before their usual bedtime. Those who reported more exertion during the sports fell asleep faster, woke up fewer times during the night, and slept more deeply than those who exercised less vigorously.1
The students who exercised with higher levels of exertion also reported increased tiredness, less hunger, and better mood at night. The researchers concluded:2
“Against expectations and general recommendations for sleep hygiene, high self-perceived exercise exertion before bedtime was associated with better sleep patterns in a sample of healthy young adults.”
Though surprising, it’s not the first time vigorous exercise shortly before bed has been linked to better sleep. A study published in 2011, however, found that when people exercised vigorously for 35 minutes right before bed they slept just as well as on nights when they didn't exercise.3
Another study, a poll by the National Sleep Foundation, found that 83 percent of people said they slept better when they exercised (even late at night) than when they did not.4
More than half of those who exercised moderately or vigorously said they slept better on workout days than non-workout days, and just 3 percent of late-day exercisers said their sleep quality was worse when they exercised than when they did not. The National Sleep Foundation concluded that exercise is good for sleep, regardless of the time of day it's performed, noting:
"While some believe exercising near bedtime can adversely affect sleep and sleep quality, no major differences were found between the data for individuals who say they have done vigorous and/or moderate activity within four hours of bedtime compared to their counterparts (those who did vigorous or moderate activity more than four hours before bedtime).
According to the 2013 Sleep in America® poll, the conclusion can be drawn that exercise, or physical activity in general, is generally good for sleep, regardless of the time of day the activity is performed."
Is Nighttime Exercise Right for You?
For some people, evenings may be the most convenient time to fit in a workout. So if exercising in the evening allows you to fit in regular workouts, this is definitely better than not exercising at all. The key here is to listen to your body.
Most experts will agree that the best time for YOU to exercise is when you will do it consistently! The most important thing is to choose a time of day you can stick with, so that exercise becomes a habit.
I would generally discourage exercising in the evening, especially if it's vigorous exercise like Peak Fitness or you struggle with your sleep. Exercise raises your heart rate and body temperature, which are not conducive to sleeping. However, if evening is the most convenient time of day for you to exercise and you find that it does not interfere with your sleep, then you should continue.
Alternatively, reserve your evening exercise sessions for gentle, relaxing exercises like yoga, while scheduling more vigorous workouts for morning or afternoon. There is some research to suggest that morning or afternoon exercise may offer unique benefits, but if you're not sure which time of day you prefer, you can do some experimentation of your own.
Without a doubt, there are many people who are sensitive to late-night exercise, such that a vigorous session will keep them awake, and this should certainly be avoided…
What You Lose if You Don’t Snooze
Sleep deprivation is a serious health concern that many simply choose to ignore. The price for doing so can be steep. Research tells us that lack of sleep can contribute to everything from diabetes, obesity, and heart disease to physical aches and pains and irreversible brain damage.
The US Centers for Disease Control and Prevention (CDC) actually classifies insufficient sleep as a public health epidemic, as it’s crucial for virtually every tissue and organ in your body. It’s during sleep that metabolic waste products are eliminated from your brain, and it’s thought that not getting enough sleep may actually injure your brain cells, impacting your cognition.5
In fact, recent research found that people who report sleeping less each night have swelling in a brain region that indicates faster cognitive decline,6 while older men who reported poor sleep were more likely to face subsequent cognitive decline.7
Furthermore, among people between 50 and 64 years of age, those who slept less than six hours a night, on average, or more than eight hours a night, had lower brain function scores.8
As for even more research looking into how lack of sleep affects your brain function, in one recent animal study, sleep-deprived mice lost 25 percent of the neurons located in their locus coeruleus, a nucleus in the brainstem associated with wakefulness and cognitive processes.9
The research also showed that "catching up" on sleep on the weekend will not prevent this damage. Other research published in the journal Neurobiology of Aging suggests that people with chronic sleep problems may develop Alzheimer's disease sooner than those who sleep well.10
Burnout Is the Enemy of Sleep
If you're cutting down on sleep in order to get ahead in your career while juggling a household and your kids' jam-packed schedules, such findings should give you pause. As noted in The Atlantic:11
"For some, sleep loss is a badge of honor, a sign that they don't require the eight-hour biological reset that the rest of us softies do. Others feel that keeping up with peers requires sacrifice at the personal level—and at least in the short-term, sleep is an invisible sacrifice."
Many are impacted by the tendency to sacrifice sleep for work and other obligations. According to the 2013 International Bedroom Poll by the National Sleep Foundation, 25 percent of Americans report having to cut down on sleep due to long workdays.12 On average, Americans get only 6.5 hours of sleep on weeknights, but report needing 7.25 hours in order to function optimally. A recent Atlantic article recommended the following tips for getting more sleep:13
- "Start by getting 30 minutes more than you are getting now. Everybody has 30 minutes." And, "Have a 'thrive buddy'—someone who can help you if you are tempted to binge-watch Breaking Bad [in lieu of sleeping]. You can call your thrive buddy and they can talk you down."
- "At the end of each day, think of something that no longer serves you. It could be a grudge you are holding against someone, someone you’re angry with, or it can be a project that you started in your head, but you’re not really going to do anything about it. It is very liberating to realize you can complete a project by dropping it."
- "At the end of the day, pick a time when you turn off all of your devices and gently escort them out of your bedroom. It’s terribly important. Because otherwise, if you have it charging by your bed, and you wake up in the middle of the night for whatever reason, you're going to be tempted. You allow your daytime with its challenges and problems that we all have to deal with to intrude into your recharging night time."
- "When you get up in the morning, one thing that has made a big difference in my life is not to immediately go to my smartphone. Take, like, one minute."
Trouble Sleeping? Try Losing Weight
One of the ways that weight loss helps your body is by helping you get a good night’s sleep. In a study presented at the joint meeting of the International Society of Endocrinology and the Endocrine Society in Chicago, it was revealed that people who lost at least 5 percent of their bodyweight after six months slept an average of nearly 22 minutes more each night.14 Your weight, exercise levels, and your sleep are all intricately connected.
Just as weight loss may help you sleep better, exercise may help you both sleep better and lose weight. And lack of sleep can cause you to gain weight and also make it difficult to exercise. Safwan Badr, a past president of the American Academy of Sleep Medicine, explained that sleep, nutrition and exercise should be considered components of a “three-legged stool of wellness.”15 “The three are synergistic,” he says. “It's hard to lose weight if you are sleep deprived. It's hard to eat healthy if you are sleep deprived. It is hard to exercise if you're tired."
Exercise Is One of the Best Secrets for Sound Sleep
Getting back to the original question of whether late-night exercise will disrupt your sleep… it’s possible, and likely that only you can answer that question for yourself. If late-night exercise keeps you awake, move your workout to another time of day; you don’t want to sacrifice your sleep – but then you don’t want to sacrifice your workout either, as it’s one of the best tools for sound sleep. Research shows that regular exercisers report sleeping better, including falling asleep faster and having a decreased need for sleeping pills, than they did prior to the start of their exercise program.16 This is precisely why regular exercise is one of my 33 top tips for a good night’s sleep.
Personally, I prefer exercising in the morning for a number of reasons, the first being that your workout will be completed early on, leaving less chance for other obligations to eat up your exercise time. Additionally, exercising in the morning makes it easy to exercise while fasting, which will amplify the benefits you receive. But it is best to listen to your body and honor what it tells you.
Another reason to schedule your workouts first thing in the morning? Research shows that 45 minutes of moderate-to-vigorous exercise in the morning may actually reduce your food cravings, both immediately afterward and throughout the day.17 Morning exercise may also help you keep moving even after your workout, which is another key to optimal health. So if you can swing it, give morning workouts a try. If not, don’t stress… fit your workouts in when they’re most convenient for you.