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Interval timer

Run HIIT, Tabata, EMOM and boxing rounds with a screen you can read from the floor.

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Your workouts

The workout

Total 4:00

20 s work, 10 s rest, 8 rounds

Two short beeps 10 seconds before the end of any phase of 30 seconds or more, like a boxing timekeeper.

Save workout

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Importing replaces what's here. The data it replaces is kept on this device, below.

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How it works

A workout is a list of phases: get ready, an optional warm-up, then work and rest for each round, sets with a longer rest between them, and an optional cool-down. There's no rest after the last round, because the workout is over.

When you press Start, the page fixes the workout to the clock, so it stays on time if you switch apps or the page is busy. Work fills the screen with bright orange and rest with deep teal, so you can tell them apart by brightness alone. In the last three seconds of each phase you hear 3, 2, 1, and the next color rises up the screen. Work, rest and the end each have their own sound.

The Tabata preset is 20 seconds on and 10 off, eight times. That's the timing from Izumi Tabata's 1996 study, whose subjects pedaled at about 170% of their VO2max; the page times your workout and doesn't tell you how hard to go.

A locked phone pauses web pages, so the page keeps the screen on while you train. Your workouts are saved in this browser; Copy link puts one in a link.

Questions people ask

What is a Tabata workout?
Eight rounds of 20 seconds of work and 10 seconds of rest, 4 minutes in all. It comes from a 1996 study in which seven people did seven to eight such bouts on an exercise bike at about 170% of their VO2max, five days a week for six weeks; most workouts called Tabata today keep the timing, not the intensity.
What do EMOM and AMRAP mean?
EMOM is "every minute on the minute": you start a set number of reps at the top of each minute and rest for whatever is left. AMRAP is "as many rounds and/or reps as possible in a given timeframe": one long countdown while you count your own rounds.
Why is there no rest after the last round?
Because the workout is over, so a rest there would only add dead time. Boxing rules end the same way: Nevada's says the final round "includes only a period of unarmed combat".
Will I hear the beeps over my music?
The page never pauses or lowers your music, and in Safari it asks to mix its beeps with other audio. Set the beeps' volume in Settings; work and rest each have their own sound, and if you miss one, the screen's color still changes at every phase.
Does it keep going with the screen locked?
Not on a phone: a locked phone pauses web pages, so the page keeps your screen on while a workout runs. If you switch to another app and back, the workout is still on time, because it runs from the clock, not by counting.

Sources

  1. Tabata et al. 1996, Med Sci Sports Exerc 28(10):1327-30
  2. CrossFit: CrossFit terms explained (Tabata, EMOM, AMRAP)
  3. Nevada Administrative Code chapter 467 (round and rest lengths, the 10-second warning)
  4. PushPress: common HIIT setups and AMRAP lengths
  5. ACSM: high-intensity interval training ("the format varies considerably")
  6. W3C: Audio Session
  7. W3C: WCAG 2.2, 2.3.1 Three Flashes or Below Threshold
  8. MDN: Screen Wake Lock API
  9. Apple Developer Forums: JavaScript in Safari in the background