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Exercise related insomnia: Does the timing of your workout affect your sleep?
By Christina | September 14, 2008
As a Personal Trainer since 1986, I have had many questions asked regarding just about every topic related to fitness. There are a few that are more common than others and one of them is, “Does exercise at night help or hinder my sleep?”
There have been studies done to see if there is a correlation between sleep patterns and exercise time of day. Several studies indicate that regular exercise improves sleep in people with insomnia. However, the timing of exercise does affect your ability to fall asleep and get a good night’s rest.
Here’s what the research indicates:
- Postmenopausal women were found to have had better quality of sleep if they worked out in the morning than those who exercised at night
- A study of highly active young men found that prolonged, vigorous exercise 30 minutes before bedtime had little effect on sleep.
I think although the study’s results are interesting they are not indicative of most people’s sleep issues. People with chronic insomnia have increased levels of stress hormones in their blood regularly which suggests that they are extra sensitive to stress. The higher the stress hormone levels, the lower your quality of sleep will be. When you exercise your stress hormone levels increase and then several hours after a workout, a rebound effect occurs and stress hormones decrease to a level that’s lower than if you hadn’t exercised.
It makes sense then that if your body requires longer to release the stress hormones from exercise, especially if you are prone to elevated levels of stress, you will need to exercise earlier. The time it takes for stress hormones to decrease following exercise varies, depending on the individual and the intensity of the activity. In general, it takes four to six hours after a high-intensity 20-minute aerobic workout before stress hormones decrease.
If you feel you suffer from elevated stress hormones and exercise at night, try this suggestion:
- For two weeks, exercise close to bedtime. Each morning, rate your quality of sleep on a scale of 1 to 10.
- For the next two weeks, exercise in the morning or in the early afternoon. Each morning, rate your sleep quality.
- Average your rate for each of the two weeks.
Personally I would just workout earlier and save myself the 2 weeks of misery.
