I am definitely not a morning workout person. My friends think I’m a little crazy when I post my 1 am workouts, and I always here, “I heard you shouldn’t workout at night because it will keep you up and make you not sleep as well.” Well, I will tell you, I have never had a bad night’s sleep after a workout – in fact I sleep like a baby. I find that I have a less effective workout if I force myself out of bed earlier than I have to so I can get a workout in. So, my theory is, workout when it works best for you. If you are going to half-ass a workout because you’re sleep-deprived from forcing yourself to get to the gym at 6am, does that really seem logical? Hey, if you can easily get up and get a workout in before work, kudos to you! That’s what works best for you. But if you need to have some hours in your day before you have the energy to hit the weights or go for a run, don’t think it’s ever too late in the day to workout. I work until 1am and I will hit up 24 Hour Fitness after or get a workout in when I get home – because that’s what I find works best for me. I’m on my feet all day, so doing a strenuous workout before work could make me a little sluggish. I’ve done some research on the matter and wanted to debunk this silly myth. Most of my research proved almost the opposite of the myth – that late-night exercising can actually IMPROVE sleep quality. From my experience, and the many articles I’ve read, exercise not only makes you tired and ready for bed, but it can actually help you sleep better. In fact, it’s been shown that those who exercise late-night sleep better than those who do not exercise. The 2013 Sleep in America Poll found that people who exercise at any time of day report sleeping better and feeling more rested than those who don’t exercise. It also finds people who exercise in the last four hours before bedtime report sleeping just as well as those exercising earlier in the day. More than half of vigorous and moderate exercisers reported sleeping better on days they exercised, even if it was close to bedtime. In the poll of 1,000 people, just 3% of late-day exercisers said they slept worse. A whopping 83% of vigorous exercisers reported very or fairly good sleep quality, versus only 56% of non-exercisers.* According to the National Institute of Health article Effects of vigorous late-night exercise on sleep quality and cardiac autonomic activity, while sleep hygiene recommendations are that intensive exercising is not suggested within the last 3 hours before bedtime, this recommendation has not been adequately tested experimentally. Therefore, the effects of vigorous late-night exercise on sleep were examined by measuring polysomnographic, actigraphic and subjective sleep quality, as well as cardiac autonomic activity. The results showed effects on cardiac autonomic control with increased heart rate in the first 3 hours of sleep on exercise days, but concluded that vigorous late-night exercise does not disturb sleep quality. Regular physical activity has consistently been associated with better sleep in survey studies, and modest positive effects on sleep have also been reported after acute exercise. The mechanisms behind the beneficial effects have been suggested to be related to the energy conservation, tissue restitution and temperature downregulation theories of sleep (Driver and Taylor, 2000; Dworak et al., 2007). The mostly accepted hypothesis is that exercise-induced body heating may activate both temperature downregulation and sleep through the anterior hypothalamus-preoptic area in the brain (McGinty and Szymusiak, 1990). Modern neuroscientific theories suggest that brain energy metabolism and specific neurotransmitter systems may play a crucial role in homeostatic sleep regulation. In addition, exercise may ease anxiety and stress.** So exercise regulates sleep and alleviates stress and anxiety? Sounds like a win-win-win to me! The following chart is from an article I read from the Huffington Post. It states that people who identify as exercisers reported better sleep than those who consider themselves non-exercisers, according to a new National Sleep Foundation survey, even when both groups get the same amount of sleep.*** While results vary slightly from other articles and studies I’ve read, it gives a good visual of how well exercise in the late hours improves sleep quality overall.
(Green: very good – Red: fairly good – Purple: fairly bad – Blue: very bad)***
So to wrap this up, the only downfall or negative effect I found on late-night workouts was on sleep hygiene (eww!) With increased heart rate, you increase body temperature – and therefore perspire a bit! (Maybe – I never wake up in sweat-soaked sheets.) According the the American Academy of Sleep Medicine, vigorous late-night activity may produce increased arousal and lead to inadequate sleep hygiene. Physiological activation during sleep after a day including strenuous physical activity were reported, however no negative effects on sleep quality were observed.** So even though you may sweat a little more in your sleep when exercising within the few hours before bed, your overall sleep quality will not be negatively affected – if anything, it may improve…You just may need to wash your sheets more often 🙂 This is Gigi. She gets tired just watching me workout.
References:
* USA Today: http://www.usatoday.com/story/news/nation/2013/03/04/sleep-survey-exercise-insomnia/1955117/
** National Institutes of Health: http://www.ncbi.nlm.nih.gov/pubmed/20673290
*** Huffington Post: http://www.huffingtonpost.com/2013/03/04/sleep-exercise-sleep-in-america_n_2784457.html