In an ideal world, I would exercise first thing in the morning. I’d also be well rested, someone else would be available to watch my children, and the weather would be warm enough that I could run through my neighborhood without slipping on ice.
But the stars rarely align for all this to happen. That’s why lately I’ve been hitting the treadmill at night after my youngest child goes to bed. There are arguments for and against 8:00 p.m. exercise, but none of the "con" arguments hold up if the alternative is not to exercise at all.
The "pro" argument is simple: Most people do little of consequence after 8:00 p.m. While mornings can be rushed, lunchtime exercise introduces the shower question, and post-work hours can get sucked up by work emergencies, by late evening, most people are just watching TV. This is low-value time. It is prime for repurposing. If you go to the gym, it will be empty. If you work out at home (for convenience, or because you’re in charge of sleeping children), you’re using time you might have spent sorting the mail. You don’t care if you’re smelly because you’re not going anywhere. There is little opportunity cost.
Of course, there are arguments against evening exercise, too. First, morning exercisers tend to be more consistent. Fitness tracker Jawbone looked at data from its users and found that while exercise tended to happen during two peaks during the day—before work and after work—users who exercised at least three times per week were much more likely to work out in the morning than in the evening. "People tend to have a much stricter routine in the morning," says Brian Wilt, director and head of data science and analytics at Jawbone. "They wake up at the same time, they go to work same time." If you’ve built a workout into your morning schedule, you will do it. But "there’s a lot more variability in the end of people’s days," he says. "It’s a little bit harder for people to keep a routine."
Then there’s the matter of discipline. If you’ve had a rough day, it becomes very easy to have two beers at dinner and decide that the couch is more compelling than a workout video. Jawbone data show that physical activity drops pretty quickly after 9:00 p.m.
Finally, sleep experts have traditionally warned people against exercising at night for fear it will keep them from falling asleep.
But all of this is surmountable if exercise is important to you, and nighttime is the best time for your schedule. Promising yourself that beer as a reward for exercise might make it easier to push the drink forward just a half hour. The sleep concerns turn out to be a nonissue: Recent research finds that exercise helps people sleep better, period. Evening exercisers don’t sleep worse than people who don’t exercise. Plus, if you work out from 8 to 8:30 p.m., and go to sleep at 10:30 p.m., you still have two hours to wind down.
Or maybe exercise will help you wind down. Sarah Coish, who works in marketing and communications, does home-based DVD workouts at night. "I find my energy level is still high by 8:00 p.m., and exercise helps me wind down from the day," she says. After exercising, she goes back online to respond to emails in a far less tense state than before. "I feel exercising helps me work through that—so I feel more refreshed, come up with new approaches, and my mind is more at ease at the end of the day," she says.
As for consistency, the key is finding something you truly want to do. Fortunately, late-evening exercise can also be exhilarating if done right. Harmony Smith, who runs outdoors in the dark, says that for a while she used an app called Zombies, Run!, which involved listening to a story about being a runner in a post-apocalyptic world. "The app tracks your speed and if you don’t run fast enough, the zombies get you," she says. Needless to say, "It was a lot more exciting to use this app at night."