This Is the Best Time to Work Out, According to Science

When it comes to personal fitness, getting an expert-approved routine down can be tricky. How often (and for how long) should you exercise? What should you eat before and after a workout? And do you need to eat before exercising at all? But to maximize your gains when you sweat, you should pay attention to the time of day you exercise, too.

What is the best time to work out?

Making time for exercise is sometimes as challenging as the actual workout. When it comes down to it, the best time to exercise is when you can. And exercise timing is very subjective, explains Bianca Beldini, a doctor of physical therapy and a USA Triathlon Certified Coach. It might take some trial and error to find what works for your body. Plus, you shouldn’t let exercise timing deter you from working out since there are so many benefits of exercise no matter when you work out, too.

Morning workouts may have the most benefits

One of the biggest advantages—and the top reason the morning is the best time to work out—is calorie burn, according to registered dietitian Emily Tills, a nutrition coach with a Masters in Applied Exercise Science who works with athletes. “When our bodies wake up in the morning, our metabolism and calorie burn rises as well to accommodate the increase in blood flow to the entire body and ‘[warm] up’ the muscles for the day,” Tills says. Meanwhile, our metabolism uses less energy while we sleep. So the bump in metabolism and calorie burn when people wake up in the morning—plus morning activity—leads to a greater calorie burn throughout the day, according to Tills. Try adding these 8 exercises that will flatten your belly without a single crunch to your morning sweat session.

Exercising in the afternoon or evening still burns calories, but since your body will soon rest during sleep, it doesn’t capitalize on the extra activity throughout the day like a morning workout, Tills says. That’s why Tills recommends a.m. exercise, if possible, to get the most energy burn throughout the day and prevent the excuse of having no energy at night. Austin Martinez, the director of education at StretchLab and certified strength and conditioning specialist, adds that there are other physiological benefits to working out in the morning, like increased blood flow which helps with mental capacity and prepares the body for the day ahead.

Don’t turn your nose up at afternoon or nighttime workouts

Although the evening might not be the best time to work out, afternoon and nighttime exercise isn’t meaningless. If exercising in the morning isn’t an option, it’s still worth adding a workout to your day in the afternoon or evening. For some people, it can actually be better to exercise in the afternoon or early evening, so you aren’t sacrificing sleep to exercise, according to Jasmine Marcus, a physical therapist and strength, and conditioning specialist. One study in the Journal of Physiology found that exercising in the afternoon shifts your human body clock similarly to an early morning workout. “The downside to this is that some people will have a harder time going to sleep if they exercise too close to their bedtimes,” Marcus says. Although, research published in Experimental Physiology found that nighttime workouts might not disrupt sleep as much as we think.

Exercising consistently is half the battle

The bottom line is the best time to work out is during a time that you can stick with that also feels best for you. Marcus, Martinez, and Tills all agree that consistency is key. “Our bodies are hardwired for routine and habits, so if you create a consistent routine for your workout times, this will yield positive results,” Martinez says. Be careful to allow enough rest time between workouts if you do vary the time you exercise each day. “Harder workouts, such as heavier strength training, require at least 48 hours of rest between sessions,” Marcus says. “So, for example, working out Wednesday morning after a Monday night workout may not be adequate time for proper recovery.”

Staying consistent with workout timing may help you make sure it gets done daily, but remember, if you can’t exercise in the morning and need to work out at night it’s not a waste, Tills says. Your body will still respond even to these quick 60-second workout moves you can almost always sneak in.