Is HIIT better than steady-state cardio?

HIIT is not better than steady-state cardio, but it does something different. HIIT gets you similar fitness gains in less time. Steady cardio is easier to recover from, so you can do more of it. For most people, the best mix is mostly steady cardio and one HIIT session a week.

What each one does

HIIT (high intensity interval training) alternates hard bursts with rest, like 30 seconds hard and 60 seconds easy. It pushes your heart and lungs close to their max, which is the strongest signal to raise VO2 max.

Steady-state cardio is longer work at a comfortable pace, like a 40 minute jog or bike ride. It builds your aerobic base and your ability to keep going. It's also easier on the mind and the body.

Where HIIT wins

• Time. Fifteen to 25 minutes can match what a longer steady session does for fitness.
• VO2 max. Intervals are one of the best ways to raise it.
• Variety. It's less boring for some people.

Where steady wins

• Recovery. You can do it 4 to 5 days a week without much fatigue.
• Lower injury risk. Hard intervals, especially running, put more stress on your muscles and joints.
• Base building. Long easy sessions are what let you hold a pace for longer.
• Beginners. You need some base before hard work is safe and useful.

How I'd combine them

Here's a simple week for someone who wants general fitness:

1. Two or three steady sessions of 30 to 45 minutes at a pace where you can talk.
2. One HIIT session, such as 6 rounds of 1 minute hard and 2 minutes easy, after a 10 minute warm-up.

Don't do HIIT more than 2 times a week unless you're advanced, and leave a rest day between hard sessions. If your legs feel heavy for days, you're doing too much.

Runs and rides synced from Apple Health are scored in League of Fitness by intensity and heart rate zones, so a hard interval session and an easy zone 2 session both count for the effort they really were. That makes it easier to keep the easy days easy.

If you take medication for your heart, have a heart condition, or feel chest pain or dizziness, talk to your doctor before doing high intensity work.