FREE TOOLS
30/30 interval timer
30 seconds hard, 30 seconds easy, with a beep at every change, free in your browser
How to use it
- Pick 10, 15 or 20 rounds, or set your own.
- Add a warm-up and a cool down under Warm-up, cool down and blocks.
- Press Start and follow the beeps: a high one for work, a low one for rest.
Why 30/30?
Equal work and rest makes 30/30 easy to remember and easy to repeat. The rest is long enough to keep every effort strong, which is why it’s popular for running, cycling and rowing intervals as well as HIIT. Read more about work and rest ratios.
| Rounds | Work | Rest | Total |
|---|---|---|---|
| 10 | 5:00 | 4:30 | 9:30 |
| 15 | 7:30 | 7:00 | 14:30 |
| 20 | 10:00 | 9:30 | 19:30 |
Session ideas
- Running: 30 seconds fast and 30 seconds jogging, 10 times, after an easy warm-up.
- Bike or rower: 30 seconds hard and 30 easy, 15 times.
- HIIT: one exercise per round, such as burpees, squats and high knees.
Questions
Is 30/30 HIIT?
Yes, when the 30 seconds of work are hard. With equal rest it’s gentler than 40/20 or Tabata, which makes it a good place to start. See what HIIT is.
How many rounds of 30/30 should I do?
10 to 20 rounds is a common range, as in the running interval timer. Start with 10 and add rounds as you get fitter.
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Cero is free to download for iPhone, iPad and Apple Watch.
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Cero is a timer, not a medical device. If you’re new to hard exercise, are pregnant or have a health condition, check with your doctor first, and stop if you feel unwell.