Another common claim is that sprinting builds muscle, particularly in the glutes, hamstrings, and quadriceps. “On social media, when people say you’re gonna lose fat and gain muscle, it makes it sound really extreme—like we’re really gonna get shredded. That’s not what’s gonna happen,” says Hirsch.
Still, sprinting does activate large muscle groups and fast-twitch fibers, which can lead to some hypertrophy, especially in those new to training. A 2009 study found that women had a greater growth hormone spike after sprinting than men, which could result in more muscle development in women than men. But don’t expect significant gains unless you’re pairing it with strength training.
“It’s not necessarily a replacement for strength training, but what it can do is promote maintenance of muscle size and muscle power,” says Vincent. Hirsch agrees: “Weights are still your best stimulator of muscle, but sprinting does stimulate muscle better than any kind of steady state cardio, like a long run or a walk.”
How to safely add sprinting to your routine
Sprinting sounds simple in theory—just run fast. But it’s more demanding than it looks. “You wouldn’t want to just jump off the couch and then immediately start a really high intensity sprint training program,” says Clark.
Start with a solid fitness base. If you’re not there yet, walking or jogging may be a better entry point. Then, ideally with guidance from a trainer or coach, you can work sprint intervals into your routine. Hirsch recommends starting with two sessions a week and capping at three; otherwise, you may overdo it and wear your body out.