Exercise is one of the most important tools for staying healthy. It helps us to manage weight and improves cardiovascular and mental health. Exercise can also reduce our risk of certain diseases like diabetes and some cancers.
The Centers for Disease Control and Prevention (CDC) recommends 150 minutes of moderate-intensity exercise each week, which amounts to about 30 minutes five days per week or 75 minutes of vigorous-intensity exercise weekly. This amounts to running or other vigorous forms of exercise twice per week in addition to at least two sessions of weight training.
But is there a time of day when you get the most benefit from exercise? According to Cameron Mitchell, an associate professor in the School of Kinesiology at the University of British Columbia, the best time to exercise is when you have time. “The majority of people don’t get enough exercise,” Mitchell says. Therefore, fitting it all in should be the first priority.
Fitting In Your Exercise Routine
Mitchell adds that the data doesn’t show that exercising at any certain time is best for most of us. “It’s different for everyone,” he says.
A small study published in a September 2021 issue of Research Quarterly for Exercise and Sport had a similar finding. In terms of barbell resistance performance, overall, people performed best when they exercised at their preferred time, whether morning or evening.
Another study published in the May 2022 issue of Frontiers in Physiology compared women and men in morning and evening exercise. The findings showed that women who exercised in the morning reduced abdominal fat and blood pressure, while women who exercised in the evening saw better muscle performance while men who exercised at night enjoyed lower blood pressure, less fatigue, and burned more fat, says Milica McDowell, a former adjunct exercise science professor at Montana State University and an exercise physiologist at Gait Happens.
Still, it’s difficult to glean from these results whether time really makes a difference. It might also be that it impacts other factors of life like sleep or replacing what you would be doing during that time if you weren’t exercising, like eating potato chips or lounging on the sofa.
Read More: Why Walking Might Be One of the Best Exercises For Health
Does Exercising at Night Disrupt Sleep?
Most experts contend that vigorous exercise right before bed disrupts sleep hygiene.
A July 2023 study published in the journal Cureus found that intense exercise at night disrupted sleep quality. “[E]ncouraging people to widen the time interval between exercise and bedtime could improve sleep quality,” wrote the study authors.
High-intensity exercise releases endorphins that can cause the brains of some people to be activated right before bed, which might make it harder to get to sleep. At the same time, exercise raises the body’s core temperature, which takes an hour or more to come back down to normal at night and can impact sleep.
Outside light in the evening is also associated with obesity, chronic disease, and disrupted sleep. Light is detected in the retina and moves down the pathways of the brain to the hypothalamus, the part of the brain that impacts hormones, which hinders the release of melatonin, the sleep hormone.
While the research may not highlight a particular part of the day in terms of performance, in terms of sleep, exercising in the morning or early afternoon may have the most positive impact on sleep, which can also have an impact on quality of life and diet.
Still, the bottom line when it comes to exercise is that it’s important to get it in at whatever point in the day works best for you. There’s no consensus that morning or afternoon is best, just that exercising on the regular is a must.
Read More: Is 30 Minutes of Exercise a Day Enough?
Article Sources:
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Johns Hopkins University. Exercising for Better Sleep
Research Quarterly for Exercise and Sport. Effects of Time-of-Day Training Preference on Resistance-Exercise Performance
Frontiers in Physiology. Morning Exercise Reduces Abdominal Fat and Blood Pressure in Women; Evening Exercise Increases Muscular Performance in Women and Lowers Blood Pressure in Men
Sara Novak is a science journalist based in South Carolina. In addition to writing for Discover, her work appears in Scientific American, Popular Science, New Scientist, Sierra Magazine, Astronomy Magazine, and many more. She graduated with a bachelor’s degree in Journalism from the Grady School of Journalism at the University of Georgia. She's also a candidate for a master’s degree in science writing from Johns Hopkins University (expected graduation in 2023).