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

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.

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.

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.

If you're trying to lower your bottom blood pressure number, going for a steady, moderate workout might work better than doing short, intense sprints — especially if those sprints last 30 seconds or more.