High Intensity, Interval Training
The timer above is set to 40 seconds on, 20 off, eight rounds. A solid default HIIT block. Press start.
HIIT is short bursts of hard work with brief recovery, repeated. The "high intensity" part is the part that matters. If you can hold a conversation through it, it isn't HIIT yet. It's just intervals.
Pick a Work-to-Rest Ratio
The ratio is the dial. One-to-one, like 30 on and 30 off, is approachable. Two-to-one, the 40/20 set above, is the common sweet spot. Three-to-one or steeper is for short, savage bursts.
Start nearer one-to-one and earn the harder ratios. More rest isn't weakness. It's what lets the next interval actually be hard, which is the entire point. Open Settings to change work, rest, or rounds.
What Counts as a HIIT Movement
Anything you can push to near-max and recover from quickly. Bike sprints, rowing, burpees, jump squats, kettlebell swings, battle ropes, hill sprints.
Compound, full-body movements give you the most for your twenty minutes. Skip anything so technical it falls apart once you're gassed. Tired and complicated is how people get hurt.
Why HIIT Earns Its Reputation
The appeal is time. Twenty hard minutes can tax both your aerobic and anaerobic systems in a way an hour of steady jogging doesn't. A lot of stimulus in a short window.
The afterburn effect is real but oversold. Your body does burn a few extra calories recovering afterward. It's a bonus, not the main event. The main event is the work.
One honest caveat: HIIT is demanding by design. Two or three sessions a week is plenty for most people. Daily max-effort intervals are a quick route to burnout or a nagging injury.
HIIT, Tabata, and Plain Intervals
Tabata is HIIT with the dial cranked all the way: a strict 20/10 for eight rounds, four minutes, genuinely all-out. If that's the workout you want, the Tabata timer is preset to it.
If you want a gentler structure or a fully custom ratio, the interval timer handles any work and rest you set.
Using This Timer
Press start. A three-second countdown gives you time to get set, then the first work interval begins. A sound marks every switch between work and rest, so you can keep your head in the effort instead of on the clock.
The preset buttons cover Tabata, 30/30, 40/20, EMOM, and boxing rounds. Settings lets you build your own.