Let’s talk about the F word: fatigue. For years, Well+Good has been reporting on the prevalence of people feeling exhausted, parsing the difference between being just plain tired versus experiencing actual fatigue, and understanding the many types of fatigue you may be feeling. But, then there’s the question of what to do about it. When you’re especially fatigued and considering how to get more energy, is it best advised to nap or exercise?

First, know that a lot of the leading factors that tend to lead to fatigue and exhaustion likely aren’t serving your health. For instance, take stress, which “is extremely draining and can lead to fatigue,” Shelby Harris, PsyD, sleep-health expert and author of The Women’s Guide to Overcoming Insomnia, previously told Well+Good. There are a number of other psychological and physiological factors contributing to why you may feel TATT (tired all the time), too, including when you consume caffeine.

Regardless of the reason, though, there are two common answers to the question of how to get more energy when you’re tired: through quality zzzs and physical activity. For the purpose of recharging your internal battery, when it comes to determining whether to sleep or exercise for more energy, it’s less a question of either/or and more a matter of both, according to Todd McGrath, MD, sports medicine specialist at the Hospital for Special Surgery. But sleep should be your first priority.

Sleep is more important than exercise for helping you get more energy

Simply put: “The body doesn’t function without sleep,” Dr. McGrath says. So if you aren’t getting the recommended hours of shut-eye for whatever phase of life you’re in, no amount of exercise is going to compensate for it. “The benefits of exercise are significantly limited if your body isn’t rested enough to recover from the exercise,” he adds.

“The benefits of exercise are significantly limited if your body isn’t rested enough to recover from the exercise.” —Todd McGrath, MD, sports medicine specialist

So your first step toward upping your energy levels should be taking stock of how much you’re hitting the hay and the quality of sleep you’re getting. There are lots of health wearables and apps that can help you track your sleep. But if you prefer not to take technology to bed with you, there are ways to tell if you’re getting a good night’s sleep that you can use to gauge for yourself.

And if you’re positive that your sleep is on point, but you’re still feeling tired throughout the day, then exercise might be your best answer to the question of how to get more energy, Dr. McGrath adds

But exercise can boost your energy instantly and overall

The endorphins release from physical activity helps you feel a little bit more awake right away, according to Dr. McGrath. In fact, research shows that quick HIIT workouts can give you the same buzz as a cup of coffee. This is something to keep in mind if you find your energy waning in the afternoon and aren’t trying to consume caffeine—especially if a power nap isn’t possible.

“In the long-term, regular exercise, particularly aerobic exercise—though resistance exercise is also important—increases cellular metabolism, which helps you process and formulate energy a little better on a molecular system scale, so you feel a little bit more energized throughout the day,” Dr. McGrath says.

An easy way to choose between sleep or exercise for more energy

The best way to tell if sleep or exercise is the more likely antidote to your low energy levels is to determine if you’re getting enough quality zzzs every night—at least seven hours. If not, it’s better to prioritize snoozing over a morning workout, for example.

If your sleep game is strong, then upping your physical activity (with an emphasis on aerobic exercise) can lead to both immediate and ongoing improvements to your overall energy.

When feeling fatigued or overly tired is more of an “in the moment” issue like an afternoon slump, as opposed to a chronic problem, opting for a four-minute, quick burst of high-intensity exercise can wake you up the same way as a cup of coffee. Meanwhile, power naps of about 20 minutes can leave you feeling more alert, focused, and productive, so they’re nothing to sleep on, either.