Can exercise improve your sleep? We can go on for days talking about how important sleep is, but the fact of the matter is that for many people, getting quality sleep, let alone fall asleep in the first place, is much harder than we think. Exercise is great for a host of health benefits, such as improving heart health with cardio and HIIT, to improving overall strength with resistance training. And time and time again it’s been shown that exercise will also help with getting more shut-eye at night. But for those of you that need a bit more convincing, as if you already need more reasons to exercise, here’s some very real and clear evidence of the magical sleeping aid called exercise.
First, understand that to invoke sleep, our body follows a near 24-hour cycle known as the circadian rhythm. Based on different cues and signals, this rhythm knows when to tell you when it’s time to go night night. One way in doing so is by raising body temperature. Through the circadian cycle, your body slowly increases in heat, reaching its highest temperature at night right before sleep. This, along with the lack of light, signals the body to increase the sleep-inducing hormone melatonin. People struggling to sleep can use exercise as a way to actively increase body temperature in hopes to drive this signal.
On top of that, a byproduct of burning more energy with exercise is raising levels of adenosine, another hormone responsible for making you feel tired and sleepy. Another pesky thing that inevitably makes it harder to sleep is age. With age, the responses to sleep signals and the circadian cycle slows down. As we saw, exercise can help with that silly circadian guy and it does not discriminate with age. In fact, a 6-month long study of elderly individuals partaking in a resistance training program not only saw a 38% improvement in sleep quality based on the Pittsburgh Sleep Quality Index, but the folks even saw an awesome 52% increase in upper body strength.
Sleep better AND open pickle jars easier? That’s a win-win! Oh, and in case exercise alone is not good enough as you grow older, another study showed that engaging in weight training, walking, and more social activities improved sleep for older individuals better than doing any of the three alone. And for people that have the most trouble sleeping, like people with chronic insomnia, exercise has undoubtedly shown to improve sleep. A study showed that as little as one exercise session was able to not only help people suffering chronic insomnia sleep faster, but also sleep longer. The exact reason why is not fully known, but possible reasons are one, the link to body temperature and the circadian rhythm as discussed before, and two, exercise can lower anxiety and depression symptoms, which is something that many with chronic insomnia suffer as well.
Sleep better and be in a better mood. As far as the type of exercise, it seems that any type will undoubtedly improve sleep. We know resistance training improves sleep based on earlier studies and might make you rip a few sleeves. But studies show that, yes, cardio improves sleep as well. A representative study of over 2600 people of all ages performing at least 150 minutes per week of moderate to intense exercises, including cardio, on average reported a 65% improvement in sleep. They even felt less sleepy during the early hours of the day!
This is even more true for people with insomnia, as studies showed that low intensity exercises are much more effective than higher intensity. And the time you exercise matters, too. When you exercise in the morning, and especially outdoors, you’ll come in contact with more sunlight, which is a signal to the circadian cycle to increase wakefulness and lower sleep-inducing melatonin levels. That means by working out early, you’ll feel more energetic throughout your day. Other studies have shown that you can also benefit from working out in the afternoon because at this time, you will be at your strongest.
And you might have heard that working out at night will make your sleep worse, but luckily, that’s not true. A study from the Journal of Sleep Research found that 35 minutes of exercise 2 hours before sleep did slightly increase heart rate during sleep, but it had no effect on sleep quality. In fact, exercise at night might help you sleep better by first raising your core body temperature and then quickly cooling you down, which is something that happens when you sleep. So choose a time to workout that’s best for you.
At the end, exercise at any time will be better than exercising no time. With 40% of the population having sleep troubles, finding out ways to improve sleep is extremely important. And based on that, exercise seems like a no-brainer. So head to the gym, the park, the dance class, the garage, wherever you might be working out, and go get your exercise and get your sleep.
Good lifting and good night.