Train consistently, sleep well
When you exercise can affect your sleep quality in many ways, said neuroscientist Jennifer Heisz, PhD, of McMaster University, Hamilton, Ont.
First, she said, “exercise helps you fall asleep faster and sleep deeper at night.” (The only exception is if you exercise so intensely or so close to bedtime that your heart rate is still elevated.)
Second, “exercising at a consistent time every day helps regulate the body’s circadian rhythms.” It doesn’t matter if the exercise is in the morning, evening, or anywhere in between. As long as it’s predictable, it will help you fall asleep and wake up at the same times.
Outdoor exercise is even better, she said. The sun is the most powerful regulator of the circadian clock and works in tandem with physical activity.
Third, exercising at specific times can help you overcome jet lag or adjust to an earlier or later shift at work.
“Exercising at 7 a.m. or between 1 and 4 p.m. helps your circadian clock to ‘fall back’ in time, making it easier to wake up earlier,” Dr. Heisz said. If you need to train your body to wake up later in the morning, try working out between 7 p.m. and 10 p.m.
All exercise is good, but the right timing can make it even better
“The best time to exercise is when you can fit it in,” Dr. Arciero said. “You’ve got to choose the time that fits your lifestyle best.”
But context matters, he noted.
“For someone needing to achieve an improvement in their risk for cardiometabolic disease,” his study shows an advantage to working out later in the day, especially for men. If you’re more focused on building upper-body strength and power, you’ll probably get better results from training in the afternoon or evening.
And for fat loss, the Skidmore study shows better results for women who did morning workouts.
And if you’re still not sure? Try sleeping on it – preferably after your workout.
A version of this article first appeared on WebMD.com.