Is it a club? No, it’s a 24/7 hour gym playing the same house soundtrack as the discotheque. When everyone else outside is entering their evening in heels, these “gym rats” are stomping in sneaks. I remember seeing 24/7 gym storefronts in places like Mexico City and Rio de Janeiro. And of course in the U.S. and beyond there’s the whole 24 Hour Fitness franchise, and other gyms with all-hour access in places all over. While it might be a lucrative business move to maximize the use of your fitness facility, rather than let it lie dark and dormant half the time, is it good to be working out at all hours of the night?
So many of us squeeze in our exercise routines between the hustle and bustle of daily life, instead of thinking about what time is the most beneficial for our overall health. If we’re not up late at the gym, we’re fitting it in on a lunch break or at the crack of dawn before the kids wake up. If we want to maximize the health benefits of working out, is the time of day we choose to do it really an important factor? And from a health standpoint, if we all had the ability and our 24/7 access cards at the ready, is there a universally-agreed-upon time that would ultimately be best to exercise?
It turns out yes, and no.
The morning lark vs. night owls debate
There’s always the war between morning larks and night owls. The 5 a.m. wake up runners vs. the nighttime yogis. TIME Magazine’s 2019 article “This Is the Best Time of Day to Work Out, According to Science” conclusively declares “morning” the winner, launching into a metabolism-centric reasoning: “Working out in the morning—especially on an empty stomach—is the best way to burn stored fat, making it ideal for weight loss.”
But the article later suggests that it might not be so clear-cut, referencing this quote by Anthony Hackney, a professor in the department of exercise and sport science at the University of North Carolina Chapel Hill, “[T]here’s really no bad time to exercise…and the most important thing is finding the time to do so, whenever works for you.”
And the ideal time to workout becomes murkier still, when we consider the night shift workers whose mornings may be others’ nights, and vice versa. And then there is the idea of a more integrative approach to exercise. There are the parts of the world where exercise and physical activity are embedded in the lifestyle, called “blue zones,” for example. So is it really as simple as morning vs. night?
The most important thing is that you workout at all
Doctor Mary Pardee, an LA-based naturopathic medical doctor and a certified functional medicine doctor who specializes in integrative gastroenterology and hormone balancing, says no.
Actually, she says the biggest factor is what time works for your schedule.
“If you pick a time that is not convenient the chances of skipping workouts increases significantly,” she says. “This is especially true for people who have a hard time sticking to a regular workout schedule in general. If this is the case then the only thing you should be considering is what time you will actually be able to workout.”
The best time to workout may depend on your goals
She notes that if you have a more flexible schedule and can workout in the morning or the afternoon, the time you choose will depend on your goal.
“I ask people what their goal is,” she says. “If their goal is to improve performance, then I suggest the person choose the time they feel the best at [to exercise]. Some people report they have more energy in the afternoon so this would be a better time for them, vs. other people report more motivation first thing in the morning. If someone's goal is to improve energy levels throughout the day and they are not focused on their performance then timing your workout based on your energy levels can be helpful.”
For example, she says, if you notice you experience that afternoon slump and feel tired around 3 p.m. each day, then timing your workout to happen just prior (say 2 p.m.) can, “... help to increase your body's natural production of cortisol, dopamine and adrenaline that are released with exercise. These hormones and neurotransmitters help to increase energy, motivation and a sense of vitality that may help to prevent a dip in energy in the afternoon.”
Follow your natural cycles
The 2022 New York Times article “Is It Better to Exercise in the Morning or the Evening?” details a study where mice were used to examine the circadian rhythmic approach and the molecular reactions to exercise. Mice scampered on tiny treadmills at different times of the day in tune with their natural 24-hour circadian “inner clock,” the study found. “When the mice jogged at the start of their active time—equivalent to morning for us—the researchers counted hundreds of molecules that increased or dropped in number after the exercise, and that differed from levels seen in mice running closer to their bedtimes or not exercising at all.”
While the rodent test audience is parallel to the findings in their human counterparts, the New York Times article still rejects a conclusive one-size-fits-all approach, ending with the line “the best time for people to exercise would be whenever they can get a chance to exercise.”
Dr. Pardee says there is something to following your natural cycles. She says something to keep in mind when deciding when to workout is your sleep-wake cycle.
“I don’t recommend that someone wake up earlier in order to exercise, unless they are able to shift their bedtime earlier,” she says. “Sleep quality and quantity are essential to health and seven to eight hours of sleep should be a priority over an early morning workout. If morning workouts are the ideal time for someone's schedule then simply shifting the bedtime to accommodate 7-8 hours of sleep is recommended.”
Should you workout at the same time each day?
Dr. Pardee says there is research that shows that we will adapt to the time of day that we exercise. So, she says, “There is likely benefit to sticking to a time of day to allow your body to adapt to it to improve performance metrics.”
However, she acknowledges that with the reality of how busy people’s schedules are, “it is really common that the same time of day does not work throughout the week.”
She says working out at different times of the day throughout the week is better than not working out at all.
Is it OK to wake up and go straight into exercise?
Dr. Pardee says yes, you can wake up and exercise right away.
“You may notice that it takes you a little while to get going,” she says. “This is because your body may experience neuromuscular deficits in the morning which means it may take your nervous system and muscles time to wake up and respond to stimuli to be able to produce maximal power.”
She says the research shows that people can “usually adapt to the time of day that they work out though, so if you continue to work out first thing in the morning then you likely will become adapted to it and be able to perform at a higher level as your body adapts to the timing.”
What about working out right before bed?
Exercising right before bed, on the other hand, is a no-go.
“I do not recommend that people workout right before bed because of the hormonal changes that exercise has on the body,” Dr. Pardee says. “When we exercise our blood pressure increases, we produce more cortisol, adrenaline, and dopamine. All of these things make us more awake and alert, which is the opposite of what you want right before bed.”
Dr. Pardee says, ultimately, there is not a huge difference between working out in the morning, afternoon or evening (as long as there’s some time for your body to cool down an reset before you go to sleep). After all, the morning lark and night owl are both birds. And fear not, night owls: You may not have to ring the alarm early. Dr. Pardee encourages each person to consider your hormones, your stomach, your sleep and your energy. The best time for you may not be the best time for me.
Mira Kaplan is a Boston-born and LA-based freelance writer. With a background in Urban Studies and Art History, her work lies at the intersection of music, art and community engagement. Whether creating soundscapes from traffic noise or photographing pink things in public spaces, curiosity drives her storytelling.