What HIIT means
HIIT stands for high-intensity interval training. It alternates short bursts of hard effort with rest or easy movement, instead of a single steady effort. The details vary a lot from one program to another, but the idea is the same: work hard, recover, repeat. The preset on this page is 30 seconds of work and 30 seconds of rest for 10 rounds, a ten-minute session.
Work-to-rest ratios
A ratio describes how long you work compared with how long you rest. Common patterns include:
| Ratio | Example | Feel |
|---|---|---|
| 1 : 1 | 30 seconds on, 30 seconds off | A balanced, approachable starting point |
| 1 : 2 | 20 seconds on, 40 seconds off | Easier, and useful for very hard efforts or beginners |
| 2 : 1 | 40 seconds on, 20 seconds off | Harder, with less recovery |
| Longer intervals | 1 to 4 minutes hard with equal rest | Often used on a bike, rower or hill |
The Tabata timer uses a 2 : 1 pattern, while the interval timer lets you set any combination.
How hard is hard?
The work periods should feel challenging but controlled. A rough check many people use is the talk test: during the work, speaking a full sentence should be difficult. During the rest, your breathing should start to settle. If your technique falls apart, slow down. Good form with strong effort beats sloppy reps at top speed.
Choosing exercises
- Low impact: cycling, rowing, swimming, incline walking and step-ups.
- Bodyweight: squats, push-ups, high knees, mountain climbers, lunges and plank variations.
- Running: short sprints or hill repeats, with a walk back down as the rest.
- Mixed: rotate through four or five moves so that no one muscle group does all the work.
Warm up, cool down, recover
Begin with five to ten minutes of easy movement that raises your heart rate gradually, then include a few practice reps of your first exercise. Afterward, walk until your breathing settles and stretch lightly. Many programs suggest allowing recovery time between hard sessions, so consider starting with one or two a week and noticing how your body responds.
Safety
Intervals are demanding. Stop if you feel dizzy, unwell or any pain. If you are new to exercise, are pregnant, have a health condition or are returning from an injury, check with a qualified professional before starting.
Other pages that pair well with this one include the boxing timer for round-based training, the plank timer for core holds and the 10-minute timer for a plain countdown.
Questions
What is HIIT?
HIIT, or high-intensity interval training, alternates short periods of hard effort with periods of rest or easy movement. The exact lengths vary. A common beginner pattern is 30 seconds of work followed by 30 seconds of rest.
How long should a HIIT workout be?
Sessions often run from 10 to 30 minutes, not counting a warm-up. Because the effort is high, shorter sessions can be plenty. This page starts with ten rounds of 30 seconds on and 30 seconds off, which takes ten minutes.
How often can I do HIIT?
Many programs suggest allowing recovery between hard sessions, so starting with one or two a week is a common approach. How often suits you depends on your fitness, other training and how you feel. A qualified trainer can help you plan.
Do I need equipment for HIIT?
No. Bodyweight moves such as squats, lunges, push-ups and mountain climbers work well, and you can add a bike, rower, jump rope or kettlebell if you have them. Pick movements you can do safely while tired.