If you’ve been with us for a while or participated in any of our programs, you’ll know that one of our main principles is how connected the body is. Sleeping well leads to better eating habits. Proper nutrition allows you to exercise more efficiently. Better physical health leads to better mental health. All of these lifestyle factors are interconnected and by improving one aspect of your health, you can improve the others and amplify your performance. This is what we call the ripple effect.
One of the topics that we haven’t covered yet is the connection between sleep and exercise. Sleep is incredibly important for physical performance (just ask any professional athlete!). But exercise is also important for getting a good night’s sleep. This week we’re going to discuss the science behind both of these factors.
As we’ve discussed previously, when you sleep you cycle between various stages from rapid eye movement (REM) sleep, to light sleep, to deep sleep. These sleep stages have different functions and are all important for proper recovery and regeneration. Unlike REM sleep and lighter stages which are more integral in recovery for the brain, deep sleep is more important for recovering the body. Deep sleep is when our heart rate and breathing rate slows, our blood pressure drops, and our muscles relax. This allows our tissues and muscles to repair and rebuild themselves. One of the key aspects of deep sleep is the release of Human Growth Hormone (HGH) from the pituitary gland. HGH repairs cells and tissues, promotes fat breakdown, increases muscle mass, and improves the body’s ability to recover from the physiological stresses that occur during exercise and daily life. If you are sleep deprived and have less HGH in your system, not only will you restrict your body’s ability to recover while you are sleeping, but you also will limit your ability to exercise the next day. Bottom line — when you sleep well, your body repairs and heals itself so you’re able to exercise well the next day.
But it also works the other way around! We now know that exercise is important for sleep. You might have noticed that on those days when you’re sitting at your desk all day, you end up tossing and turning all night long. However, on days that you are active, you are able to fall and stay asleep more easily. In fact, regular exercise has been shown to improve sleep in young, middle-aged, and older adults — including those with sleep disorders. It’s logical that if you are tired from a workout, you will have a better sleep. But there’s a lot more to it! Here are a couple of hypotheses as to why a workout helps you get some quality shut-eye:
1. Exercise helps to regulate body temperature. Your circadian rhythm is your internal biological clock which regulates everything from your mood, to your physical performance, to alertness, to your hunger levels throughout the day. At night, there is a natural drop in your body temperature which is important for you to fall and stay asleep. While more research is needed, it is thought that exercise is important for promoting this drop in body temperature that occurs at night.
2. Brain-derived neurotrophic factor (BDNF). Previously we’ve discussed how exercise can increase levels of circulating BDNF, which stimulates the growth of new neurons. This is one of the reasons why exercise improves mental alertness, learning, and memory. However, it is also hypothesized that this increase in BDNF can improve sleep at night. Studies have shown that increased levels of BDNF in the brain can help promote sleep, particularly deep sleep. So exercise can help you feel more alert during the day AND help you fall asleep at night!
So on those days you’re really tired and you can’t imagine doing a workout? Try to get up and move — even if it’s for 15 minutes! Go for that quick walk at lunch, or do that short yoga practice. In addition to boosting your energy levels during the day, it will also help you sleep at night, allowing you to recover properly and do a more intense workout the next day.
If you’re using the VIIVIO app, pay attention to your Move and Sleep scores. On days you get a high Sleep score, you might also get a high Move score, and vice versa. Write down your scores this week and see if you notice a trend!
The only thing to watch out for is the timing of your exercise. You don’t want to do anything too intense within a couple hours of going to bed as this can increase your body temperature too much and has been associated with reduced sleep efficiency. However, light and even moderate exercise don’t appear to negatively affect sleep if done within a couple hours before bed. However, this is all individual so if you find you’re better off exercising in the morning then stick with that! One great exercise to do right before bed is a light yoga or stretching routine. Remember stretching can help activate your parasympathetic nervous system, calming your body down before bed.
What are we finding in the research?
A recent review article discusses some of the proposed mechanisms for how exercise leads to improved sleep. The authors suggest that signalling molecules produced by skeletal muscle during exercise, such as BDNF, might play a large role in promoting sleep.
You can read the full article here.