The most famous HIIT protocol, from Dr. Izumi Tabata: 20 seconds all-out, 10 seconds rest, repeated 8 times = 4 minutes. It builds both aerobic and anaerobic fitness fast.
Every Minute On the Minute. Do a fixed number of reps of an exercise at the start of each minute, then rest for whatever's left. Finish early = more rest. A great format for consistency and pacing.
As Many Rounds As Possible. Pick 3-5 exercises, set a time window (e.g. 10-20 minutes), and complete as many rounds as possible while keeping good form. It measures your work capacity round after round.
Move through a series of exercises back-to-back (30-45 seconds each) with short rests between rounds. A full-body way to keep your heart rate up while building strength - no equipment needed.
Short, maximum-effort sprints (bike, run, row, or jump) followed by longer recovery. Boost speed and VO2 max in far less time than steady-state cardio.
Yes. Fitxel uses the Screen Wake Lock API so the display never dims or locks while the timer is running - no tapping to keep the screen awake mid-set. On older iPhones it automatically falls back to a built-in technique so the screen still stays on.
Fitxel sets the iOS audio session to "playback", so the adaptive Web Audio beats keep playing even when your iPhone's mute switch is on. No more silent workouts.
Set LOW TIME = 10 seconds, HIGH TIME = 20 seconds, and TOTAL CYCLES = 8. Each cycle plays 20 seconds of work followed by 10 seconds of rest - a full 4-minute Tabata.