Some people swear by a 6 a.m. jog to get their hearts racing and get 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 information to suggest that calories are burned more efficiently at certain times of day. But studies have shown that the time of day can influence how you feel when exercising.
The most important thing 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 there are other important considerations, such as family and work schedules, or a friend’s availability to exercise with you.
The Perks of Morning Exercise
If you have trouble with consistency, morning may be your best time to exercise, experts say. Research has shown in terms of performing a consistent exercise habit, individuals who exercise in the morning tend to do better. The thinking is people get their exercise in before other daily pressures begin to interfere with time to exercise.
It is recommended 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.
It’s sometimes easier to keep a morning workout routine consistent. Afternoon and evening workouts are more likely to conflict with other responsibilities during the day. Plus a full day’s work can take a serious toll on willpower—which can overcome any gym-goer’s best intentions.
Morning workouts might also be a good option for stress-free snoozing. Since exercise increases heart rate and body temperature, working out too late in the evening (generally after 8 p.m.) may disrupt sleep, while one study showed that working out at 7 a.m. (compared to 1 p.m. or 7 p.m.) may help people sleep more soundly at night.
Finally, one study found that 45 minutes of moderate morning exercise (like walking briskly on the treadmill) helped curb appetite directly after working out. Research also shows that people can burn up to 20 percent more body fat exercising on an empty stomach—much easier to do first thing in the a.m. than at night.
Plenty of people tout the benefits of early morning sweat sessions, but if you can’t fit in a workout before noon, you always have the rest of the day. Research suggests the body can adapt to regular gym times, so if we exercise every day at 4 p.m., eventually we may perform better at that time than at any other time of day. These findings are similar to earlier research, which suggests that sticking to a specific workout time can result in better performance, higher oxygen consumption, and lower perceived exhaustion.
Your body’s core temperature is an important factor in determining the quality of exercise. A cold body leaves muscles stiff, inefficient, and susceptible to sprains, whereas higher body temperatures leave muscles more flexible. Body temperature typically increases throughout the day, so muscle strength and endurance may peak in the late afternoon, when body temperature is highest. The afternoon is also when reaction time is quickest and heart rate and blood pressure are lowest, all of which combine to improve performance and reduce the overall likelihood of injury.
Hormone levels are also important in determining optimal workout time. Testosterone is important for muscle growth and strength, in ladies and gents. And the body produces more testosterone during late afternoon resistance training than it does during morning workouts. Plus, the stress hormone cortisol, which aids in the storage of fat and reduction of muscle tissue, peaks in the morning and decreases throughout the day and during exercise. But morning workouts can be successful too.
What Really Matters
What really matters is finding a realistic, consistent workout schedule, no matter what the time. If working out in the morning is best for your schedule, just make sure to warm up muscles that might be cold and tight from sleep. And to keep afternoon workouts consistent, treat them as unbreakable appointments, find a workout buddy, and keep a gym bag in the car or office to minimize excuses.