Are early-morning workouts actually healthy? As long as you're getting enough sleep, they are.

• Early-morning workouts are gaining popularity on TikTok.
• Sacrificing sleep for exercise can lead to health problems.

For busy people, waking up at 5 a.m. to exercise might feel like the only way to get in shape.

Communities of 5 a.m.-ers are popping up across social media. The hashtags #5amFitness and #5amWorkout combined have more than 40 million views on TikTok.

The sunrise fitness fests are certainly popular, but are early-morning workouts actually good for you? Turns out, it depends.

Your body needs sleep

"The important thing is getting a total of seven to eight hours of sleep," said James Maas, a sleep expert and the author of "Sleep for Success."

Sacrificing sleep to exercise can be tempting for people with jam-packed schedules, but this approach can cause problems if it's not handled correctly. Sleep deficiency can cause heart problems, kidney disease, stroke, depression, irritability, and a slew of other issues, according to the National Heart, Lung, and Blood Institute.

Stick to a schedule

If you're going to try early morning exercise, start by planning a schedule that gives you an opportunity to get those precious seven to eight hours of sleep. You will need to choose one bedtime and one time to wake up that works for your lifestyle and stick to it every day. Yes, even on the weekends.

It may take two or three weeks to feel comfortable with your new schedule. If you're already a morning person, you will adjust quickly to the earlier hours, but if you're a night owl, it will take longer for your circadian rhythm to shift.

Once you get into a regular routine, it will get easier to dive into your workout, but don't move too quickly.

"Early-morning exercise, if you're sleepy, makes you much more vulnerable to injury or accidents," said Maas. He always reminds athletes to plan enough time in their schedule to stretch and warm up because your brain needs time to become alert.

Don't rely on caffeine for a daytime boost

As you adjust to your sunrise fitness sessions, you might be tempted to load up on caffeine midday, but caffeine and alcohol can mess with your sleep schedule, so avoid drinking them later in the day. To get a good night's sleep, experts recommend that you stop drinking caffeine within six hours of bedtime and alcohol within four hours of bedtime.

Most people have a natural drop in their circadian rhythm in the early afternoon that makes them feel sleepy, and you might feel it more than usual if you join the early exercise club. Rather than pounding a coffee, stay hydrated and squeeze in a midday nap.

"Taking a power nap not longer than 20 to 30 minutes, typically after lunch, affects your amount of valuable sleep and also improves your memory and cognitive abilities," said Maas, who originally coined the term "power nap" back in the 1990s. He warns that a nap longer than 30 minutes could leave you feeling groggy.

Some workouts are better in the morning than others

Even if you've followed the right steps in preparing your body for morning exercise, deciding whether it's the best time to work out depends on your goals.

"Teams who do two-a-day workouts or just do mornings are worse off in terms of their performance than those who just do one a day at about 4 o'clock in the afternoon," said Maas.

That said, there are still a few benefits for the early risers.

If you are exercising outside, your body and mind will benefit from the sunshine. The sun exposure can boost your levels of vitamin D and improve your mood.

Physical activity is also widely known to decrease stress, so doing it when you first wake up starts your day on a positive note. One study found that participants were more focused and made better decisions throughout the day after morning exercise.

Another benefit that comes with break-of-dawn exercise is the calm and quiet environment that only exists when everyone else is still in bed.

Early-morning exercise can be a convenient choice, but it's not the definitive solution for everyone. The most important consideration is planning your timing carefully to get seven to eight hours of sleep every night.

"You've got to be committed to a schedule and keep it Monday through Monday, including the weekends," Maas said.