Common HIIT timer settings
| Setup | Work | Rest | Rounds | Time |
|---|---|---|---|---|
| 30/15 (built-in HIIT Standard) | 0:30 | 0:15 | 8 | 5:45 |
| 20/40, an easier start (set it yourself) | 0:20 | 0:40 | 8 | 7:20 |
| 30/30 (set it yourself) | 0:30 | 0:30 | 10 | 9:30 |
| 40/20 (built-in EMOM Style) | 0:40 | 0:20 | 10 | 9:40 |
| 45/15 (built-in Endurance Builder) | 0:45 | 0:15 | 12 | 11:45 |
| 60/30 (built-in Strength Intervals) | 1:00 | 0:30 | 6 | 8:30 |
None of these ratios is an official standard: they're common setups. Times leave out the get-ready and the rest after the last round. Round counts differ, so compare the work and rest rather than the totals. For 20 seconds on and 10 off, see the Tabata timer page.
Choose what you can finish with good form. More rest usually lets you work harder in each interval, and less rest keeps your heart rate higher. Many people new to intervals begin with more rest than work, like 20/40, and shorten the rest as it gets easier.
Set up a HIIT workout in Interval Pal
Interval Pal is the timer we make. HIIT Standard, Endurance Builder and Strength Intervals are built in. For anything else:
- Open the Timer tab.
- Set work, rest and rounds. To cycle through several exercises in each round, set exercises to how many you're doing.
- Tap play, or tap Save to keep it for next time.
The total time updates as you change the numbers, so you know how long the session takes before you start.
What two studies found
A 2012 review by Gibala and colleagues looked at high-intensity interval training in healthy people and in people with disease. It reported that interval training can produce similar or even better changes than traditional endurance training when the work done is matched. Low-volume interval training is less well studied, but it can produce changes comparable to moderate continuous exercise in less time.
A 2014 meta-analysis pooled 10 studies with 273 patients who had coronary artery disease, heart failure, high blood pressure, metabolic syndrome or obesity. VO2peak is a measure of aerobic fitness. Theirs rose by about 3 ml/kg/min more with interval training than with moderate continuous training. The authors put that at 9.1% and describe it as almost double the gain.
Neither study tested the settings in the table above, so they don't show that one ratio beats another.
The NHS counts HIIT as very vigorous exercise. It advises speaking to your GP first if you have not exercised for some time, or if you have medical conditions or concerns.
What Interval Pal does and doesn't do
- A big countdown, a sound at each change and 3-2-1 beeps before it, over your music and with your phone locked.
- Up to 30 exercises per round, up to 50 rounds, and a longer rest between rounds if you want one.
- Save your own workouts and start them in one tap.
- It doesn't plan workouts or count reps, and there's no Apple Watch app.
Questions
What's a good work-to-rest ratio?
There isn't one right answer. See the table above, and start where you can keep good form for every round. The Tabata vs HIIT comparison explains where 20/10 fits.
Will I hear the timer over my music?
Yes. Cues play over your music and with your iPhone on silent. See the interval timer with music page.
Is Interval Pal free?
It's free to download. Running a workout needs Pro: start with a 7-day free trial of the yearly plan, or choose monthly or a one-off lifetime purchase. Prices are shown in the app before you buy.
Sources
- Gibala MJ, Little JP, Macdonald MJ, Hawley JA (2012). Physiological adaptations to low-volume, high-intensity interval training in health and disease. Journal of Physiology 590(5): 1077 to 1084.
- Weston KS, Wisløff U, Coombes JS (2014). High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: a systematic review and meta-analysis. British Journal of Sports Medicine 48(16): 1227 to 1234.
- NHS. Physical activity guidelines for adults aged 19 to 64.
Last updated 12 October 2026
Interval Pal is available on the App Store. Free to download. Running a workout needs Pro: 7-day free trial on the yearly plan, or a one-off lifetime purchase.