You know that exercise is good for you. The question is, though, is there a best time of day to log that sweat session? Will you get more benefits by working out in the morning versus the evening—or vice versa?
Here’s the good news: “Regardless of the time of day you exercise, you’ll achieve gains in cardiorespiratory fitness and strength,” says Catherine Yeckel, MS, PhD, exercise physiologist and assistant professor of clinical public health at Yale School of Public Health in New Haven, Conn.
Of course, the more important question is when you’ll be more motivated to exercise. “The best time to exercise is when you can take time for yourself and put your full effort into completing your workout,” says Marisa Mickey, MS, assistant professor of exercise science at Endicott College in Beverly, Mass. Maintaining a healthy exercise habit isn’t easy, after all, so it’s best to do what you can when you can.
That being said, though, studies have shown that different times of the day can offer different benefits, including those that relate to performance, power, metabolism, and even blood pressure, Yeckel says. Here’s what the science and experts say to help inform your personal "best" workout time.
The Pros of Morning Workouts
First, some physical health and science research. One of the advantages of morning exercise may be tied to metabolism. In one study in the International Journal of Obesity, individuals who exercised in the morning (before noon) lost more weight than those who exercised after 3 p.m. Other research has also found that 100 minutes of running before breakfast had the largest impact on 24-hour fat oxidation versus splitting the running session into 50 minutes before breakfast and another 50 minutes in the afternoon or running 100 minutes in the afternoon.
“Taken together, these studies suggest that there’s a metabolic difference to performing morning exercise,” Yeckel says. While weight loss is not the be-all and end-all for a fitness routine, it is inevitably tied to exercise and can be a personal health decision, making it important to note. (Someone who is trying not to lose weight, for example, may consider scheduling their daily jog for 5 p.m., rather than 9 a.m.)
But beyond physiological factors, working out in the morning also helps ensure that you move. “By exercising in the morning, you don’t have the opportunity to find an excuse during the day not to exercise since you’ve already done it,” Mickey says. And because exercise can improve cognitive function, which will affect memory, attention, and processing, that morning workout might be more beneficial if you’re then heading to work or school. It might even encourage you to make more health-conscious food choices during the day.
What if you’re training for a fitness event? “Because most of them have an early morning start, it’s recommended that you train at the same time of day that your event would take place, more for practical reasons than it being better to run in the morning,” Mickey says. And while it should go without saying, if you’re exercising outdoors in the warmer months, morning workouts might be a cooler and less humid time of day.
The Advantages of an Afternoon or Evening Workout
There are equally good reasons to log that sweat in the evening, starting with muscle function, which peaks in the afternoon and evening. Studies show that afternoon appears to increase parameters that many athletes strive for in terms of repeat sprint performance, velocity, and peak power, as well as muscle mass gains, Yeckel says.
This makes exercise in the latter half of the day advantageous if you’re doing strength training, repeat efforts needed for cycling or running, or endurance performance. And regarding exercise endurance, endurance performance, or time to exhaustion, among competitive cyclists has been shown to be longer in the evening than the morning, Yeckel says. In terms of health, blood pressure control might even benefit more with afternoon or evening exercise.
Another reason to love those evening workouts? Because exercise has proven mental health benefits, including stress relief, that evening workouts could provide a well-needed mental break after working or taking care of kids all day, Mickey says. Just make sure you pay extra attention to your form, as being tired can mean that you’re not fully engaged in your workout which could set you up for injury.
Plus, by unwinding from your day via evening exercise, you might set yourself up for a good night of sleep. Research reveals that sleep won't be disrupted as long as your workout doesn't fall too late close to bedtime, Yeckel says, no matter whether you exercise in the morning or late afternoon.
What’s the Bottom Line?
Whether in the morning or afternoon, your first priority should be finding the time that’s easier for you to exercise regularly. Studies show that working out at a consistent time each day, regardless of morning or evening, has benefits. “Being consistent in the time you work out may give you the routine and structure you need to stick with your training,” Mickey says. Staying consistent with time of day for exercise is also a good idea for specific populations of people, including those with diabetes, to help maintain blood sugar levels.
However, if you have the choice between morning or evening, consider your goals. If you want to push hard to achieve peak function, exercising in the afternoon ensures that your body is already naturally more warmed up, Yeckel says. (Although, morning exercisers, don’t despair—your body will become more used to morning workouts and achieve higher levels of function over time; just note that you will need a longer warm-up in the morning). On the other hand, if starting off your day with a sweat and kicking your metabolism into gear is your primary goal, a morning workout might be your pick.