It’s important to make time for exercise on a regular basis, and for many this means squeezing in a workout early in the morning, during a lunch hour, and even late at night, just before bed.
It’s commonly suggested that you should, ideally, avoid exercising at night, however, as the increases in your adrenaline levels, heart rate, and body temperature may make it difficult to fall asleep.
Without a doubt, there are many people who are sensitive to late-night exercise, such that a vigorous session will keep them awake. For some, however, and possibly even the majority, exercise at night may not necessarily be so bad...
Some People Report Exercise at Night Helps Them Sleep Better
One of the benefits of exercise overall is improved sleep quality, but it’s typically recommended that you not exercise within three hours of bedtime so you have adequate time to wind down.
A study published in 2011, however, found that when people exercised vigorously for 35 minutes right before bed they slept just as well as on nights when they didn’t exercise. Another study, a poll by the National Sleep Foundation, found that 83 percent of people said they slept better when they exercised (even late at night) than when they did not.
More than half of those who exercised moderately or vigorously said they slept better on workout days than non-workout days, and just three percent of late-day exercises said their sleep quality was worse when they exercised than when they did not. The National Sleep Foundation concluded that exercise is good for sleep, regardless of the time of day it’s performed, noting:
“While some believe exercising near bedtime can adversely affect sleep and sleep quality, no major differences were found between the data for individuals who say they have done vigorous and/or moderate activity within four hours of bedtime compared to their counterparts (those who did vigorous or moderate activity more than four hours before bedtime).
According to the 2013 Sleep in America® poll, the conclusion can be drawn that exercise, or physical activity in general, is generally good for sleep, regardless of the time of day the activity is performed.”
Afternoon Exercise May Help Regulate Your Circadian Rhythm
There’s a case to be made for exercise at virtually any time of day, including in the afternoon. A study published in the Journal of Physiology found that exercise helps regulate your circadian rhythms, and the effect may be most profound if it’s done in the middle of the day.
Researchers designed a study comparing the circadian rhythm effects of exercising at various times of day, using two groups of mice: one healthy group and one group with biologically induced circadian disruptions.
There are potentially serious health consequences of disrupted circadian rhythms, such as increased risk of diabetes, obesity, hypertension, memory loss, headaches, indigestion, mood disorders, learning problems, and even certain types of cancer.
Disrupted sleep cycles have the potential to stimulate cancer growth by altering hormone levels, such as melatonin, for instance, showing just how important it is to regulate your circadian rhythm.
Interestingly, the study found that all of the mice showed positive benefits from exercising, regardless of what time of day they exercised (for mice, exercising meant running on a wheel). But the benefits were much higher for the mice whose internal clocks were impaired in the first place.
For those discombobulated mice, after several weeks of running, their internal clocks were much more robust, particularly among the mice that exercised in the afternoon. This finding was a real surprise to researchers who expected to see the most benefit from morning exercise, which tends to be favored by athletes.
Mice exercising in the late evening showed the least benefit, with some developing even more circadian disruptions, including poor sleep (which is contrary to the featured article’s findings).
