What HIIT is
High-intensity interval training, or HIIT, pairs short, hard efforts with short recoveries. The work should feel close to your limit, around 8 or 9 out of 10, and the rest should be just long enough to repeat that effort. Because the hard parts are short, a complete HIIT session can fit into 10 to 25 minutes.
Work-to-rest ratios
The ratio of work to rest decides how hard a session feels. Shorter rest means more fatigue and more conditioning; longer rest lets you push each interval harder.
| Ratio | Example | Good for |
|---|---|---|
| 1:2 | 20 s on, 40 s off | All-out sprints, beginners |
| 1:1 | 30 s on, 30 s off | Running and bike intervals, first HIIT sessions |
| 2:1 | 40 s on, 20 s off | Bodyweight circuits, general conditioning |
| 3:1 | 45 s on, 15 s off | Fit athletes, metabolic finishers |
| 5:1 | 50 s on, 10 s off | Moderate-intensity circuits with little rest |
Sample HIIT workouts
- Beginner, 12 minutes: 30/30 × 12 alternating squats and incline push-ups. Try the 30/30 timer.
- Intermediate, 10 minutes: 40/20 × 10 rotating jump squats, push-ups, mountain climbers, lunges and burpees on the 40/20 timer.
- Advanced, 20 minutes: 3 sets of 45/15 × 6 with 1 minute between sets.
Tips
Warm up for five to ten minutes before your first hard interval. Choose moves you can do with good form while tired, and lower the intensity before you lose technique. Two or three HIIT sessions a week, with easier days in between, is plenty for most people.
Questions and answers
How long should a HIIT workout be?
Most effective sessions have 4 to 20 minutes of actual intervals, plus a warm-up and cool-down. Longer is not better if the work stops being hard.
What is the best HIIT ratio for beginners?
Start with 1:1 or 1:2, such as 30 seconds on and 30 seconds off. Move to 2:1 when you can finish every round with good form.
How often should I do HIIT?
Two or three times a week is enough for most people. Leave at least one easier day between hard sessions.