Everyone who exercises regularly have their own favorite time to exercise. There are those who prefer to work out sometime in the morning hours. Then, there are those who work out during the lunch hour. In addition, there are those who exercise sometime during the afternoon hours. Finally, there are those who work out during the evening hours.
By the way, exercise seems to have a more beneficial impact on metabolism in the late morning rather than in the evening.
Now, the majority of those who work out in the evening hours usually do so in the early evening. This allows them to have dinner after the workout and then sleep. Or, some have dinner in the early evening and work out before sleeping.
Meanwhile, recommendations are that dinner or vigorous workout be completed at least one hour before bed. In fact, sleep recommendations have always been to finish any vigorous exercises three hours before bedtime.
Effects of Evening Workouts
But are there any downsides to working out late into the evening hours. Downsides such as being able to fall asleep. Now, a well circulated recommendation is to avoid strenuous workouts in the late evening or right before bed. And the common reasons for this recommendation is that exercise:
- Causes your body to release stimulating epinephrine, also known as, adrenaline. Fortunately, their effects dissipate within 20 minutes.
- Also, aerobic exercise causes the body to release endorphins. Moreover, these chemicals can create a level of activity in the brain that keeps some people awake. Consequently, these individuals should finish exercising at least 1 to 2 hours before going to bed, giving endorphin levels time to fall and the brain time to wind down.
- Finally, exercise raises the core body temperature. By the way, elevation in core body temperature signals to the body’s circadian rhythm that it’s time to be awake. Consequently, it becomes difficult to sleep. However, after about 30 to 90 minutes after the workout, core body temperature starts decreasing. And, this decline helps you feel sleepy.
Now, intense workouts raise core body temperature, which stays high for four to five hours. Moreover, this high temperature may interfere with your body’s need to fall asleep. By the way, the normal pattern is for your body temperature to go down as you approach bedtime. So, the intense workout interferes with this normal pattern.
But every person isn’t affected the same way. Some couldn’t care less if they just came out of a High Intensity Interval Training, also referred to as HIIT, workout. They may fall asleep as soon as they hit the bed.
Furthermore, for most people, exercising close to bedtime doesn’t appear to have any effect on sleep quality. In fact, a 2011 study reported that those who exercised for 35 minutes right before bedtime slept just as well as on those nights they didn’t exercise.
In the meantime, the National Sleep Foundation, in 2013, polled one thousand participants. And, this poll found that 83 percent of the participants who exercised at any time of the day (including before bed) reported sleeping better than those who didn’t exercise at all. Indeed, only 3 percent of late day exercisers said they slept worse on days when they exercised compared to days when they didn’t.
Lastly, a report in the journal Sports Medicine, dated February 2019, contained a meta-analysis by researchers at ETH Zurich. And, this meta-analysis pointed out that people who exercised within four hours of bedtime showed no difference with those who didn’t exercise in these three aspects:
- First, in the time it took them to fall asleep
- Next, in the time spent awake during the night after falling asleep
- Finally, sleep wasn’t any worse
Next, looking at the percentage of time spent in slow-wave sleep, or deep sleep, researchers found that exercise could improve sleep. In fact, study participants who did some type of workout within four hours of bedtime spent an average of 21.2 percent of the night in deep sleep. While those who didn’t exercise within four hours of bedtime spent an average of 19.9 percent of the night in deep sleep. So, the workout had little impact of the amount of deep sleep they got.
Vigorous Exercise or HIIT
The only exception was HIIT or vigorous exercise. Indeed, vigorous exercise an hour before going to sleep can mess up your sleep. This is because your heart rate gets so high during the HIIT workout, that one hour isn’t enough time for your heart rate to go back to its resting rate. As a result, your body isn’t as relaxed and ready to fall and stay asleep.
So, the lessons learned is to keep the evening workout at low to moderate intensity or less. In fact, researchers think that with moderate intensity your parasympathetic nervous system kicks in, which slows down your heart rate and relaxes you. But everyone isn’t the same, so you need to see what workout intensity works for you.
Besides, a lot of people generally find it difficult to do vigorous aerobic exercise in the evenings and go straight to sleep. While, it might be a great time to exercise in terms of burning calories, it might be hard to fall asleep after that. Not for everybody, but for a lot of people.
On the other hand, if evening time is the only time you can exercise, and then go for it. However, leave a one to two hours gap before sleeping to allow your body to get its sleep mechanisms to work. And, if getting to sleep is difficult, there are many ways to help. For example, warming or massaging your feet will calm you down and help sleep.