After a quick 9-minute workout, sprint intervals might make your heart take longer to calm down compared to burpees or steady hard exercise — at least in young, somewhat active people.

Sprint and hard steady workouts get your heart pumping faster and keep it near maximum longer than burpee workouts in young, somewhat active people — at least during 9-minute sessions.

Short, intense bursts of exercise (like sprinting) can boost heart and lung fitness just as well as longer, steady workouts — and take way less time.

Doing short bursts of all-out exercise for at least 8 weeks might lower your top blood pressure number more than steady, moderate workouts—especially if each burst is under 30 seconds.

When young and older men do short, super-intense bike or sprint workouts, the young guys get better at using oxygen during exercise, but the older guys don’t — their bodies just don’t respond the same way.

For young adults who exercise a bit, doing a quick 9-minute sprint workout leads to bigger drops in muscle power—like how high you can jump or how strong your legs and arms feel—compared to other similar workouts using burpees or steady hard exercise.