Doing short bursts of intense exercise might boost heart fitness more than steady, moderate workouts for people with heart disease — on average by a small but measurable amount.

For people with heart disease, short bursts of intense exercise don’t seem to work much better than steady, moderate exercise when both burn the same number of calories — both help a bit, but the difference between them is tiny.

Doing short bursts of intense exercise for 12 weeks doesn't improve the maximum oxygen your body can use during exercise in people with excess body fat, even though they can exercise longer before getting tired.

Doing steady, moderate workouts might boost your heart and lung fitness more than super intense but short sprints, even though the moderate workouts take longer.

Both short, intense sprints and steady, moderate workouts boost teenage boys' stamina just as much after six weeks — either way, their bodies get better at using oxygen.

For heart patients, how much total energy you burn during exercise might matter more than whether you do intense bursts or steady workouts — when both types burn the same calories, they seem to help your fitness just as much.