An interval timer you can read from across the room
This interval timer runs your HIIT, Tabata or EMOM workout for you. Set the length of the work, the length of the rest and the number of rounds, press Start, and follow the screen. The time left in the current phase fills the screen in huge numbers, with the phase and the round above it, such as “Work · round 3 of 8”.
During rest, the two colors swap: the screen turns white and the numbers take the color. Put your phone on the floor or your laptop on a bench, and you can tell from across the room whether it is time to push or to breathe. Different sounds mark each change, so you can also train without looking. There is no app to install, no account and no ad between rounds, and the page keeps the screen on while the timer runs.
How to set up a workout
The settings read as a sentence: “20 s of work, 10 s of rest, 8 rounds, with a bell”. Turn a wheel with your finger or the mouse, or tap the middle of a wheel to pick a value in a larger list.
| Setting | Range | Default |
|---|---|---|
| Work | 5 seconds to 10 minutes | 20 s |
| Rest | 0 to 10 minutes | 10 s |
| Rounds | 1 to 50 | 8 |
| Get ready | 10 seconds before the first round | Always on |
The big number shows the total time of the workout before you start. The timer ends after the last work interval: there is no point resting at the end. Your settings are saved on this device for next time.
What you hear
- Three short beeps during the last three seconds of every phase: get ready.
- Two rising notes: work starts.
- Two falling notes: rest starts.
- Your chosen sound (a bell, a chime, a beep or a gentle rise): the workout is over.
The sounds are scheduled in advance by your browser, so they stay on time even if you switch to a music app, as long as the page stays open.
Popular interval formats
The bar at the bottom of the screen sets the most common formats in one tap. Each one has its own page with sample sessions:
| Format | Work | Rest | Rounds | Total time |
|---|---|---|---|---|
| Tabata | 20 s | 10 s | 8 | 3:50 |
| 30/30 | 30 s | 30 s | 10 | 9:30 |
| 40/20 | 40 s | 20 s | 10 | 9:40 |
| EMOM | 1 min | Rest of the minute | 10 | 10:00 |
- Tabata comes from a 1996 study by the Japanese researcher Izumi Tabata. Four minutes, very hard.
- 30/30 is the gentlest ratio, and a classic of running clubs.
- 40/20 fits each round into one minute, ideal for circuits.
- EMOM means “every minute on the minute”: you do your reps at the start of each minute and rest for what is left.
How to build a HIIT session
HIIT, for high-intensity interval training, alternates short hard efforts with recovery. A complete session has three parts:
- Warm-up, 5 to 10 minutes: easy cardio, mobility, then a few short accelerations.
- The intervals, 10 to 25 minutes: one or several blocks set on this timer.
- Cool-down, 5 minutes: slow walking or pedaling, then some stretching.
Beginners do well with more rest than work, such as 20 seconds on and 40 seconds off, and 2 sessions a week. As you get fitter, shorten the rest, add rounds, then move to harder ratios. Simple moves work best: squats, lunges, push-ups, jumping jacks, mountain climbers, burpees, a jump rope, a bike or a rower.
Choosing work and rest
The ratio between work and rest sets the difficulty more than the exercise itself:
| Ratio | Example | What it feels like |
|---|---|---|
| 1:2 | 20 s of work, 40 s of rest | A gentle start, plenty of time to recover |
| 1:1 | 30 s of work, 30 s of rest | Balanced, a classic for runners |
| 2:1 | 40 s of work, 20 s of rest, or Tabata 20/10 | Hard: the heart rate stays high |
| Work only | EMOM, a new round every minute | The faster you work, the more you rest |
Shorter, harder efforts suit sprints and jumps; longer efforts at a steadier pace suit circuits and running. Change one thing at a time from one week to the next: rounds, then work, then rest.
Train safely
Hard intervals put a real load on the heart. If you have a heart condition, high blood pressure, or have not exercised for a long time, check with your doctor first. Stop at once if you feel chest pain, dizziness or unusual shortness of breath. Keep good form, even if it means fewer reps, drink water and leave at least one day between two hard sessions.
Tips
- Go full screen with the button at the top right, and use + to make the numbers bigger.
- On a computer, the space bar starts and pauses the timer.
- While it runs, the settings fade away after a few seconds. Touch the screen to bring back Pause.
- Other timers: for a single block, use the online timer. To time laps, the stopwatch. To keep a steady cadence, the metronome.