Interval timer: Tabata, EMOM, AMRAP and rest between sets

Pick a mode, set the numbers and press Start. The timer counts work and rest for a Tabata, starts a new round every minute for an EMOM, runs one clock with a round counter for an AMRAP, or times a single rest between sets. Where each default comes from, and how each mode behaves, is below.

Run the timer

The timer needs JavaScript, which looks to be switched off. Any phone clock can run each mode by hand: the rules are below.

Where the starting numbers come from

Tabata. The default is eight rounds of 20 seconds of work and 10 seconds of rest. The 1996 study behind the name used seven to eight sets of 20 seconds at about 170% of maximal oxygen uptake, with 10 seconds of rest between sets, on a cycle ergometer.¹ A 2012 trial used the eight-round version with one bodyweight exercise per session, such as burpees, jumping jacks or mountain climbers.² How the two differ, and how hard to go, is on the Tabata workout.

EMOM. A 2024 study describes the format as doing the specified reps within a one-minute interval, with work and rest both inside each minute.³ The default is 12 one-minute rounds, the twelve minutes the EMOM workout suggests setting. Set Every to 120 for a round every two minutes.

AMRAP. The same study describes AMRAPs of 10 to 20 minutes, and ran its own for 12.³ The default is 10 minutes, as on the AMRAP workout.

Rest. The American College of Sports Medicine's 2009 position stand recommends three to five minutes between heavy sets of 1 to 6 reps for strength, one to two minutes for muscle-building sets of 6 to 12, and under 90 seconds for light to moderate endurance sets of more than 15.⁴ The default, 90 seconds, is a practical middle; rest between sets goes through which lifts need longer.

Questions

How does the Tabata mode work?

After five seconds to get ready, it runs work, then rest, for each round, and stops at the end of the last work period. So eight rounds of 20 on and 10 off take 3:50, not four minutes: there's no rest left to time after the last round. Change the three numbers for any other work-and-rest interval, such as 40 seconds on and 20 off.

How does the EMOM mode work?

Each round is a fixed interval, a minute by default. Start your set when the round starts; whatever is left of the minute is your rest, and the next round starts on time whether you're ready or not. If the set takes the whole minute, cut the reps.

How does the AMRAP mode work?

One countdown for the whole session. Tap "+1 round" each time you finish the list, and the count at the end is your score. Write it down: the page forgets it when you leave.

How does the rest timer work?

Press Start when you rack the weight. It counts down once and says when it's time for the next set; press Start again after that set. The quick buttons set one, one and a half, two or three minutes.

Does it keep time if I switch tabs?

Yes. It works the time out from the clock instead of counting ticks, so it's right whenever you look back. It never asks to keep your screen awake, so your phone may still dim or lock; to hear every beep, keep the page open in front.

Is anything saved or sent?

No. The numbers and the round count stay in the page while it's open and are gone when you leave. Sound is off until you switch it on, and the beeps are made by your browser, not downloaded.

A timer keeps the minutes honest. What goes in them, and how hard, is the part a page can't set for you. Coaching is the version where your workouts live in the Trainerize app, sized to the days you actually have, and a weekly call looks at the week you just had and rebuilds the next one. Coaching for a week that doesn't hold still explains how that works, and apply is the first step.