Interval Timer
A HIIT and Tabata timer โ work, rest, rounds, big colours and beeps.
About this interval timer
Set your work and rest lengths and the number of rounds, hit start, and train. The screen turns red for work and green for rest, the numbers are readable from across a room, and beeps count down the last three seconds of every phase โ so the phone can stay on the floor while you keep moving.
One-tap presets cover the classics: Tabata's 20/10 ร 8, a standard 40/20 HIIT block, and an every-minute-on-the-minute round. The timer follows the wall clock rather than the tab, so a backgrounded browser won't stretch a round, and your settings are remembered on this device.
Tabata, HIIT and why intervals work
The famous protocol comes from Dr Izumi Tabata's 1996 study of speed skaters: twenty seconds all-out, ten seconds off, eight times โ four minutes that improved both aerobic and anaerobic capacity in athletes training six weeks. The catch, often lost in fitness marketing, is that โall-outโ meant 170% of VOโmax; the structure is four minutes, the intensity is the hard part.
High-intensity interval training generalises the idea: alternating hard efforts with recovery lets you accumulate more time at high intensity than one continuous effort could sustain. For most people the practical draw is simpler โ intervals compress an effective session into twenty minutes, and the timer removes every decision except โkeep going until the beepโ.
Getting the most from interval sessions
- Earn the short rests. If you can talk during the work phase, lengthen it or push harder โ intervals only work at genuine intensity.
- Warm up outside the timer. The prep phase is for getting in position, not for cold muscles meeting burpees.
- Progress one variable at a time. Add a round, or trim the rest, or extend the work โ not all three in one week.
- Two to four sessions a week. True high-intensity work needs recovery days; daily Tabata usually means the intensity wasn't Tabata.
Frequently asked questions
What is the Tabata protocol?
Eight rounds of 20 seconds' work and 10 seconds' rest โ four minutes total. It comes from Dr Izumi Tabata's 1996 study, where the work intervals were performed at very high intensity; the preset here gives you the exact timing.
Does the timer keep working if my screen locks or I switch apps?
It tracks wall-clock time, so a backgrounded tab still switches phases at the right moment. On a phone, keep the screen awake for the colours โ or rely on the beeps, which play as long as the browser is running.
Can I use it for things other than workouts?
Anything that alternates effort and rest โ practice drills, stretching, speed cleaning, even writing sprints. Work, rest, rounds and prep are all adjustable.
Why can't I hear the beeps?
Browsers only allow sound after you've interacted with the page, which pressing Start satisfies โ so check the device isn't muted and the media volume is up. iPhones also silence web audio when the ring switch is on silent.