Morning, afternoon, nighttime—no matter when you work out, you’ll gain the basic benefits of exercise: better heart health and immunity, improved cognition, bone and muscle strength, mood boosts, disease prevention and more. So if your schedule limits when you can squeeze a workout in, take whatever you can get.
But if you have the luxury of choosing, research has some things to say about what time of day will yield the most benefits. Unfortunately, the answer is, well … complicated. Turns out, the best time of day to workout depends on your exercise goals.
Here, we present to you our three contestants in the battle for the “Best Time of Day to Exercise” and sort through the science to see which has the edge.
Contestant #1: Morning
One of the strongest reasons to work out in the morning is to make sure it happens at all. Research suggests that a.m. exercisers also tend to be the most consistent with their workouts. Some studies, including a recent one in the International Journal of Obesity, also showed that working out before noon is linked to greater weight loss than exercise at other times of day. The jury is still out as to why that is, although some research shows exercising first thing in the morning may diminish your appetite for the remainder of the day.
Evidence also connects morning workouts to reduced stress and better sleep; for example, a study published in the Journal of Strength and Conditioning Research found that 7 a.m. exercisers had 10–25 percent lower blood pressure and better sleep cycles than those who worked out at other times.
Contestant #2: Afternoon
It’s well-documented that, because of circadian rhythms, your muscle strength peaks in the afternoon and early evening. So if your goal is high performance and strength gains, this is your time. You’re also more flexible at this time, partly because your body temperature is at its warmest for the day. Afternoon workouts can also pull you out of a midday slump and help you release work stress.
Contestant #3: Nighttime
Although the evidence isn’t as strong as for morning, nighttime workouts are also linked to more weight loss than afternoon exercise. And you’ll still have some of the greater muscle strength and flexibility that afternoon exercisers enjoy, although it declines as the evening progresses. Nighttime exercise can also mess with your body clock, leading to later bedtimes and less sleep, but this varies from person to person.
And the winner is: morning! Unless you’re a high-performance athlete looking for major strength and performance gains, get your workout in before other things crowd it out—and enjoy greater weight loss, lower stress and better-quality sleep for the rest of the day.