How Today's Workout Affects Tonight's Sleep

Exercise and sleep are essential for a healthy, happy body — and it turns out, more time spent sweating can actually boost the quality of your shut-eye. But just how does moving more lead to better z’s, and how can you maximize these bodybenefits? We asked experts in sleep, exercise, and neurology for the science behind exercise and how it makes you sleep better. Here are their golden rules of resting.

“Lack of sleep, and dysfunctional sleeping (e.g.,sleep apnea), can create domino effects of at least 10 different mechanisms falling out of sync, many of which affect weight loss,” says W. Christopher Winter, M.D., president of Charlottesville Neurology and Sleep Medicine and author ofThe Sleep Solution.

First, the stress hormone cortisol will ramp up, which “can keep you awake at night and affect glucose metabolism, or the way you store fat.” Also, when you sleep less, you tend to eat more “because leptin, the hormone that signals ‘I’m full and satisfied,’ gets suppressed,” he says. To add to the triple threat, “ghrelin, the hunger hormone that is made in the gut, also gets ramped up when you don’t sleep well, making you crave carbs,” Winter explains.

Exercise halts the first of those chain reactions by reducing cortisol levels, says Meg Furstoss, MS, CSCS, founder of Precision Sports Performance. “Most people start to feel the impact of the day’s stress at night, so exercise helps clear that out.”

Furstoss recommends doing cardio-based exercises, which have been shown to reduce the signs of insomnia in healthy people, according to the journal Sleep. But she also strongly recommends incorporating resistance exercise forsleepand fat-loss goals: “Weightlifting is best for weight loss because lean musclesburn fatat a quicker rate,” she says.

Research shows that resistance exercise such as weightlifting alone (i.e., when not done at the same time as cardiovascular exercise) is super-beneficial for all aspects of sleep, according to 2017 study analyses inSleep Medicine Reviews. Resistance training was shown toraise the quality of sleep and to improve anxiety and depression. Study analyses of more than 3,000 adults from age 18 to 85 found that exercise also aided infalling asleep fasterand reducing the chances of feeling overly sleepy during the day, according to the report published inMental HealthandPhysical Activity.

Slow-wave sleep is where a lot of the restorative magic happens, and exercise can help you get more of it. Your muscles, bones, and tissues can be repaired during non-REM (rapid eye movement), slow-wave sleep. Once that sleep becomes REM (aka the dream state), the parts of your brain used for learning get stimulated.

Researchers from the University Of Basel, in Switzerland, objectively monitored the sleep of more than 40 college students to test whether vigorous physical activity (20–60 minutes) createdbetter sleep outcomes than moderate exercise. Those who did vigorous activity slept longer overall; spent more time instage 4 (deep) and REM (rapid eye movement) sleep; and had less light sleep in exchange for more slow-wave sleep.