When it comes to the impact that exercise has on sleep, there are significant benefits to be gained. Facts are that while physical activity helps to reduce your risk of cardiovascular disease and Type 2 diabetes – as well as strengthening your muscles and bones and improving your mental health and mood, just to mention a few – it also improves sleep patterns.
Physical activity fortifies circadian rhythms that promote daytime alertness and help bring on sleepiness at night. And for those suffering from a sleep disorder, including insomnia and obstructive sleep apnea, exercising may be just what the doctor ordered.
A recent National Sleep Foundation poll found that regular exercisers were significantly more likely to report sleeping well on most nights than people who were not physically active. In addition, research has also shown exercise can help to improve not only the quantity of sleep but also the quality.
However, the relationship between sleep and exercise is complex. In particular, one study suggests that increasing physical activity may not have an immediate impact on getting our ZZZ’s, but, in fact, may take several weeks or months. Also, there is a bi-directional relationship between our slumber and exercise—meaning exercise affects sleep, and sleep affects exercise. Think about the last time you tossed and turned in bed and were sleep deprived. Was gravity extra strong in keeping you sitting or lying down and skipping your workout? Or if you did workout, did you cut it short? It’s easy to see how just one night of inadequate sleep can have a negative effect on next-day workouts. Let’s take a closer look at how two critically important activities—exercise and sleep—affect one another.
Dr. Nina’s What You Need To Know: About the Relationship Between Exercise and Sleep
How does exercise promote sleep?
• One popular theory is that exercise depletes our energy stores, breaks down tissue, and elevates body temperature. And, conversely, when we sleep, our body conserves energy, tissues restore and rejuvenate, and body temperature dips (which syncs with our cool down after exercise).
• Those who suffer from sleep disturbances tend to be hyper-aroused—anxious or stressed out—or on the other end of the spectrum, depressed. Exercise functions as an effective method to soothe anxiety, stress, and depressive symptoms.
• Physical activity can also help us shed pounds or maintain an ideal body weight. Extra weight is a risk factor for obstructive sleep apnea (OSA)—when breathing stops temporarily due to complete obstruction. There is no movement of air and this causes us to wake up, often accompanied by a loud snort or gasping sound. OSA causes daytime drowsiness and fatigue as well as increases the risk for a number of chronic illnesses including Type 2 diabetes and heart disease.
Timing is important, or maybe not?
It is almost dogmatic that we should avoid exercising in the hours before we plan on going to sleep. This is because physical activity elevates our blood pressure, heart rate, alertness, and body temperature, which are the opposite of what is needed to fall asleep. Makes good sense and appears logical. However, in reality that does not seem to hold true. The 2013 Sleep in America Poll surveyed 1,000 people and found that those who exercise at any time of the day report sleeping better and feeling more rested compared to those who did not get regular physical activity. This is good news for people who only have time later in the day—after school, work, or other commitments—to get in their exercise or participate in a group activity or sport.
Will I see an immediate effect from exercise on my sleep?
Probably not. In a study published in the Journal of Clinical Sleep Medicine, researchers found that sleep quality improved greatly, but not immediately. And as noted in the opening, it can take months before an improvement is found. The good news is that when your physical activity does take impact on your sleep, it is significant—study participants gained on average 1 hour and 15 minutes more of ZZZs compared to the non-exercising control group.
Exercise decreases restless legs syndrome (RLS)
This is a common disorder that affects approximately 1 in every 10 people, but is seldom diagnosed. According to the National Institute of Neurological Disorders and Stroke, RLS is “characterized by throbbing, pulling, creeping, or other unpleasant sensations in the legs and an uncontrollable, and sometimes overwhelming, urge to move them. Symptoms occur primarily at night…” And research shows that those who exercise regularly experience a significant improvement in symptoms and can be a good alternative to prescription medication treatment.
Exercising when drowsy or tired
We have all been there, and know it is easy to want to just lounge away and consume high calorie, high-fat comfort foods (which we know pack on the pounds). Sleep deprivation is associated with elevated stress hormone levels, inflammation and pain perception, as well as impaired metabolism and energy conservation. You’re likely to feel as if you’re working harder and getting tired sooner. Add to that, elevated cortisol levels and decreased growth hormone levels—consequences of sleep deprivation—impair our body’s ability to build muscle mass.
But building up the courage to go for a walk or participate in low or moderate exercise can boost our energy levels and make us feel more awake. That is because physical activity increases endorphin levels (our body’s feel good hormones), as well as improves blood flow which can then deliver oxygen and nutrients to muscle tissues and enhance its ability to produce an energy-boosting chemical called adenosine triphosphate (ATP). Additionally, research shows that chronic exercise increases overall feelings of energy and decreases general feelings of fatigue.
Improved athletic performance
In a study published in Sleep, researchers from the Stanford Sleep Disorders Clinic and Research Laboratory examined the role of “sleep extension” in 11 male varsity basketball players. For 2-4 weeks, participants maintained their baseline sleep-wake schedule. Then, for 5-7 weeks, they increased the amount of sleep they got, with a minimum goal of 10 hours a night. Researchers found that sleep extension was associated with a faster timed sprint, improved shooting accuracy (free throw and 3-point field goal), and also decreased fatigue. Additionally, the athletes (subjectively) reported improved physical and mental well-being during practices and games.
Amount of exercise needed and timing?
According to sleep experts at the National Sleep Foundation, as little as 10 minutes of aerobic exercise, such as walking or cycling, can dramatically improve the quality of your nighttime sleep. Just think what could happen when done on a regular basis—about 150 minutes a week.
What’s more, exercisers may reduce their risk for developing troublesome sleep disorders, such as sleep apnea and restless leg syndrome.
At this time, it is unknown if different types of exercise like weight training, make a difference. With respect to timing – it turns out that exercising at night doesn’t interfere with everyone’s sleep—it depends on the individual. So if you find that physical activity in the evening revs you up too much, do it earlier in the day. But if you find that the opposite is true—maybe you come home so exhausted that you drop down into the bed and fall asleep quickly—then, it is working for you!
Sleeping and exercising are two great health benefits you can provide for your body. Regular physical activity helps you sleep, and sleeping well (quality sleep) helps you stay active. It’s a positive dynamic that can enhance your life in multiple ways.