Some people swear by a 6 a.m. jog to get their hearts racing and get them psyched up for the day. Others wouldn't dream of breaking a sweat before noon, preferring a walk around the neighborhood after dinner. But is any one time of day the best time to exercise?
The truth is that there's no reliable evidence to suggest that calories are burned more efficiently at certain times of day. But the time of day can influence how you feel when exercising.
The most important thing, experts say, is to choose a time of day you can stick with, so that exercise becomes a habit.
Your Body Clock
Your body's circadian rhythm determines whether you're a night owl or an early bird, and there's not much you can do to alter it.
Circadian rhythm is governed by the 24-hour pattern of the earth’s rotation. These rhythms influence body functions such as blood pressure, body temperature, hormone levels, and heart rate, all of which play a role in your body's readiness for exercise.
Using your body clock as a guide to when to go for a walk or hit the gym might seem like a good idea. But, of course, there are other important considerations, such as family and work schedules, or a friend's availability to walk with you.
The Perks of Morning Exercise
If you have trouble with consistency, morning may be your best time to exercise, experts say.
"Research suggests in terms of performing a consistent exercise habit, individuals who exercise in the morning tend to do better," says Cedric Bryant, PhD, chief science officer with the American Council on Exercise in San Diego.
"The thinking is that they get their exercise in before other time pressures interfere," Bryant says. "I usually exercise at 6 a.m., because no matter how well-intentioned I am, if I don't exercise in the morning, other things will squeeze it out."
He recommends that if you exercise in the morning, when body temperature is lower, you should allow more time to warm up than you would later in the day.
When Insomnia Interferes
Unfortunately, hitting the snooze button repeatedly isn't exercise. But, if you've suffered insomnia the night before, it can seem a lot more appealing than jumping out of bed and hitting the treadmill.
"Your body needs to get ready for sleep," says Sally A. White, PhD, dean and professor in the College of Education at Lehigh University in Bethlehem, Pa."You want your heart rate and body temperature in a rest zone. It starts the body getting into a habit of sleep."
Exercising or eating too late sabotages your body's urge to sleep.
"Both exercise and eating raise your heart rate and temperature," White tells WebMD. "That's not conducive to sleeping."
When Later Is Better
White, who studies achievement motivation in exercise and other areas, says that in spite of good intentions to get up early and get her exercise over with, she is more likely to exercise after work.
"It's easier to get my body into a rhythm because I'm not fighting my body the way I do in the morning," she says.
For some people, lunchtime is the best time to exercise, especially if co-workers keep you company. Just be sure to eat after you work out, not before.
"Don't exercise immediately following a meal," says Bryant, who lectures internationally on exercise, fitness and nutrition. "The blood that needs to go to your muscles is going to your digestive tract. Give yourself 90 minutes after a heavy meal."
Finding Your Own Best Time to Exercise
You don't have to be an expert on circadian rhythms to determine the best time to exercise. Steven Aldana, PhD, advises trying different times of the day.
Work out in the morning for a few weeks, then try noon, then early evening. Which do you enjoy most and which makes you feel best afterward? Also, consider the type of exercise, and other daily commitments.
"Most of all, find a time that helps you make your exercise a regular, consistent part of your life," says Aldana, a professor of lifestyle medicine in the department of exercise sciences at Brigham Young University in Provo, Utah. "This is more important than the time of day."
Establishing the Exercise Habit
One day, you'll reach a point where daily exercise comes as naturally as breathing. At that point, you may want variety.
"In an effort to stay regularly active, some people change the type of exercise they do and the time of day they do it," says Aldana, author of The Stop & Go Fast Food Nutrition Guide. "Keeping it fresh makes it more enjoyable and more likely to be continued."
But if you're still at the point where exercise is hit or miss, scheduling it for the same time each day will help you make it a habit. Whether you choose morning, lunchtime, or after work to exercise, make it part of your routine.
"People who are just starting out and who exercise randomly are more likely to drop out," White says.
She adds that starting out can be as simple as changing the route you come home from work so that you drive by a gym. "Get into the habit of going that way, and keep a bag of exercise gear in your car or at work," she says.