Exercise And Sleep: How Does Working Out Impact Our Sleep?

Written by
Purple Staff
Last Updated
September 14, 2022
min read

Getting optimal sleep has multiple benefits for physical and mental health. Interestingly, physical exercise has also been proven to improve these aspects of your well-being.

Working out during the day is an effective way to improve your physical health at any age. This is because it lowers the risk of chronic diseases such as diabetes and cancer, as well as reduces stress and anxiety. However, some of the most important benefits of exercise are linked to its relationship with sleep. 

Let’s take a closer look at the effect of exercise on sleep.

How Does Exercise Affect Sleep?

Engaging in regular physical activity allows you to hack your body clock, making for a more restful nighttime sleep at the end of your day. This is particularly helpful for individuals with sleep problems, such as adults with chronic insomnia, who rely on pharmacologic treatment to help them sleep.

Physical exertion tires you out in the process – this helps facilitate deep sleep and increase sleep time at the end of the day. When you tire yourself out due to physical exercise, your body naturally produces melatonin, a hormone that helps regulate your circadian rhythm. This tired feeling is your body resetting its internal clock that regulates your sleep-wake cycle.

Aerobic exercise (e.g. running) and resistance exercise (e.g. lifting weights) can do wonders for your mental and physical health. It has a bidirectional relationship with sleep. This means that when you incorporate or improve your exercise routine into your everyday life, you will notice that it can potentially improve your sleep quality. 

Is It Harmful To Exercise Before Bed? 

Working out too soon before bed is usually discouraged because it can affect sleep onset latency. This means that you can suffer from inadequate sleep due to your cortisol and endorphin levels blocking melatonin production. 

Exercise Intensity Matters

Some people report that doing high-intensity aerobic or resistance workouts too close to bedtime keeps them up instead of helping them fall asleep faster. This is because the human body releases endorphins when you exercise.

Endorphins, also known as “happy hormones”, can keep you awake. While this effect can differ from person to person, people’s schedules often do not permit them to exercise regularly, which can be a cause of poor sleep. 

However, if you work out before bed, a low-intensity form of exercise – such as yoga, which focuses on meditation, holding positions, and breathwork – can help you unwind and get ready for a good night’s rest. Middle-aged and older adults may also treat their disordered sleep issues by doing lower-intensity exercises within their fitness level.

How Exercise Can Help You Sleep

Sleep allows your body to recover from the previous day’s activities. When you get enough sleep after working out, you can avoid possible injuries caused by fatigue or exercise. When you don’t get enough sleep, you have less energy to go about your daily tasks.

The effects of exercise can also improve sleep indirectly. For example, individuals who suffer from sleep issues such as insomnia or OSA (obstructive sleep apnea) can prevent disordered sleep by adding aerobic activity to their daily routines.

Previous studies show that moderate to severe OSA has been attributed to obesity and cardiovascular disease – conditions that can be prevented through physical activity. It has been observed that higher physical activity levels can help reduce the severity of OSA by as much as 32%. In addition, findings from the largest randomized trial conducted by Kline and colleagues showed that up to 12 weeks of aerobic exercise decreased OSA severity by 25%, even with less than 1kg of weight loss.

In fact, exercise is seen as an alternative treatment to sleep meds – it’s one of the natural nonpharmacologic treatments often suggested to address chronic insomnia in adults.

Timing Your Exercise

When you exercise, your body produces more endorphins that keep you alert and awake. Your core body temperature is also heightened, which signals the body that it should be awake. 

In addition to that, physical exertion on the body increases heart rate and promotes the release of cortisol or the stress hormone. Cortisol blocks the production of melatonin, which prevents you from falling asleep. 

While there is no one-size-fits-all formula for the best time in the day to exercise, it is advisable to do your workouts in the morning, especially if they are of moderate intensity or more challenging. People typically recommend working out earlier in the day because nighttime sleep is better when cortisol levels drop. Your body will be more capable of producing melatonin, as well.

Working out in the afternoon can help you get enough sleep at night. Your core body temperature is highest between 2 p.m. and 6 p.m., which makes it a great time for moderate-to-vigorous physical activity. If you work out at night (up to 8 p.m.), do moderate-intensity workouts instead of high-intensity exercises to allow for natural sleep onset.

How Much Exercise You Need For Sleep

To avoid poor sleep quality, do moderate exercise for at least 30 minutes in the morning or early evening. Aim for at least 150 minutes of moderate-to-vigorous aerobic exercise training per week to see changes in the way you sleep.

The average sleep time of healthy adults is 6-8 hours of sleep per day. 

How Does Sleep Impact Exercise? 

Due to the bidirectional relationship between exercise and sleep, how much and how well you sleep also determines how much energy you have to exercise. When you have a sleep deficit, it can affect your physical activity levels in the following ways:

  • Delayed response time: Insufficient sleep delays your response and reaction to physical activity.
  • Quicker exhaustion: You may tire more easily after exercise if you don’t get enough sleep.
  • Increased risk of injury and illness: A lack of sleep can inhibit your body’s executive functions and increase your risk of getting sick or suffering physical injuries during exercise.

How Sleep Helps Post-Workout Recovery

Sleep plays a vital part in post-workout recovery alongside proper nutrition, especially if you are trying to increase muscle mass. 

When you sleep, your body produces insulin, which is responsible for regulating blood sugar levels and metabolism. This hormone transforms the food you eat into energy – as you sleep, it transports amino acids into cells for storage and protein synthesis. Pituitary glands also secrete growth hormones (GH), which your muscles need to rebuild and repair tissue.

Frequently Asked Questions On Exercise And Sleep

What is the best time to exercise for sleep?

There is no straight answer to this question. All types of physical exercise are beneficial for the body – as long as you find a consistent time to work out during the day, you will be able to sleep better.

Moderate and high-intensity workouts are ideal in the morning and afternoon, while low to moderate exercise is better done in the evening. However, any form of exercise can improve the quality of your sleep, especially when compared to complete physical inactivity.

Why can’t I sleep after exercise in the morning?

Your body works harder to keep you awake in the morning, especially after a workout. Post-exercise, the body’s core temperature and heart rate are elevated. In addition to the endorphins that produce the so-called “runner’s high”, it also produces elevated levels of cortisol, which block the production of sleep-inducing melatonin.

Can exercise help you sleep faster? 

Studies say that exercising can help you sleep faster and improve your overall quality of sleep. However, this is dependent on the time of day you do it and the intensity of your workouts.