Morning, afternoon or evening? When do you exercise? People exercise at all different times throughout the day. When you exercise is probably due to when it’s most convenient for you. But what if there’s a best time to exercise? A time when you’re more likely to reap all the benefits of exercise than any other time.
Our bodies have a built-in clock, called the circadian rhythm. This rhythm oversees your sleep/wake cycle, metabolism, eating behaviour and changes in hormones as the day goes on. For example, light suppresses production of the sleep hormone melatonin, which helps keeps us awake. Insulin and blood pressure also follow a circadian rhythm. Given this, one might expect there to be a best time to exercise.
The morning tends to be the most popular time for people to exercise. This is probably because most people prefer to get it done before the business of the day begins. That way it’s not hanging over your head. It also means your exercise won’t get bumped due to one of many of life’s daily surprises. The morning is also a popular time as can give you an energy boost similar to a morning coffee and can increase feelings of happiness for the rest of the day.
Exercising in the morning has a number of effects on food intake and metabolism. It has the potential to reduce appetite throughout the day. Although it’s not clear if this results in any changes to food intake. And changes in food intake may depend on whether you eat breakfast before or after exercise.
Exercising before breakfast means being active after 10-12 hours of fasting, something that isn’t common during the day. This results in greater use of fats for energy and lower food intake later in the day. However, six weeks of exercising before breakfast did not lead to any weight loss compared with exercising after. As well, exercising before breakfast on an empty stomach may not be for everyone as it can lead to irritability.
But food and calories aren’t all there is to exercise. Exercising in the morning can improve mental function and concentration. It can also help you sleep. A single bout of exercise in the morning resulted in a faster time to sleep compared with exercise later in the day or in the evening.
Afternoon and Evening Exercise
Exercising later in day has its own advantages. As the day goes on, your body’s temperature increases hitting a peak in late afternoon. This means it takes your body less time to warm-up than in the morning and can result in stronger muscle contraction and greater exercise efficiency. This may lead to better exercise performance as a small study found aerobic capacity to be higher in the evening than morning.
But be mindful of exercising in the evening too close to your bedtime. As exercise suppresses the sleep hormone melatonin, it may make it harder for you to fall asleep. Plus, if you’re doing intense exercise, it will take time for your heart rate and blood pressure to return to resting levels reducing the quality of your sleep. The impact is likely intensity dependent as resistance exercise in the evening still improved sleep compared with not exercising.
Afternoon exercise (between 11 am and 5 pm) may have the greatest benefit when it comes to preventing early death. A study of 92 139 adults found those who exercised in the afternoon, had the lowest risk for early death compared to morning or evening exercisers. It’s not clear whether this is a time effect of exercise as generally, heart attacks and strokes are more common in the morning. In addition, people who have time to exercise in the afternoon may have different lifestyles that allow them the freedom to exercise at that time. Regardless, the differences between the time of day groups were marginal, and the greatest gains in longevity came from comparing all exercise groups to those who didn’t exercise.
The Best Time to Exercise is When it Works for You
Whether it’s in the morning or later in the day, both times have advantages. If you’re interested in improving your metabolism or sleep, the morning may be the best choice. If performance is your goal, the afternoon is probably for you. However, one tends to perform better at the time at which you commonly train at. So if you exercise in the morning, over time, you’ll perform better in the morning than at any other time of day.
There are many other factors that come into play when deciding what time to exercise. This could depend on your work/school schedule, when community centres or pools are open, or when your training group gets together. Other factors such as the weather may influence you. If you live in a hot climate, choosing to exercise early in the morning allows you to avoid high mid-day temperatures. Conversely, in colder climates, waiting until the sun’s shining may help invigorate your workout.
Of course, the best time to exercise is when you’re able to do it. Having a routine and building habits is best. This will help ensure you’ve scheduled in your exercise when it fits you best. And any amount of exercise is better than none. If you’re just starting, find a time that works and get into the habit of doing it at that time each day.
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This post was originally published on August 12, 2020 and updated on May 3, 2023.
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