Caynax: HIIT & Tabata Timer

Caynax HIIT is a free, powerful interval timer for HIIT, Tabata, cardio and any timed workout — with live Bluetooth heart rate, colour-coded heart-rate zones, a full workout history and progress tracking.

Want to burn fat, build stamina and get more out of every minute? High-intensity interval training alternates short bursts of all-out effort with brief recovery — a flexible approach to challenging cardio sessions, even when you have only a short time to train. Caynax HIIT keeps the timing, the cues and the tracking for you, so you can focus on the work.

A REAL INTERVAL TIMER
• Build unlimited workouts: warm-up, work, recovery, rounds, long break and cool-down.
• Varied rounds: give every round its own work and recovery time.
• Twelve ready-made workouts included — Tabata, Norwegian 4x4, EMOM, AMRAP, 2:1 Grind, circuit training, Japanese Walking and five weekly programmes.
• Quick start: set work, recovery and rounds, then go. Nothing to save first.
• Create, edit, duplicate and delete your own workouts.

VOICE AND SOUND CUES
• A voice announces every stage and counts down out loud.
• Or whistles and beeps, from a set of built-in sounds.
• Count down your way: every second, every n-th second, or only the final seconds.
• Edit what the voice says (PRO), or bring your own sound files (PRO).

LIVE BLUETOOTH HEART RATE + ZONES (PRO)
• Pair any Bluetooth LE chest strap or armband (standard Heart Rate Profile).
• Live BPM while you train — current, min, average and max.
• 5 colour-coded zones from your age or your own max HR.
• Every session saves your full heart-rate curve, coloured by zone and drawn over the stages you ran.

HISTORY AND PROGRESS — FREE FOR 7 DAYS
• Automatic history of every session: date, duration, rounds, calories, completion.
• Streaks, a calendar, weekly trends, personal records and a weekly goal.
• Time in each heart-rate zone, per-workout history, notes and RPE.
• Export your history as a CSV file.
• Both screens are open for your first 7 days, then they are PRO.

BUILT FOR IPHONE AND IPAD
• A Live Activity on the Lock Screen and in the Dynamic Island: current stage, time left, and pause, back and skip without unlocking.
• Full-screen colour-coded stages, a big readable timer and a "next" preview, in portrait or landscape.
• Skip a stage, go back a stage, or hold to rewind and fast-forward.
• Keeps running with the screen locked, and plays over your music.
• Weekday reminders, so a training day never slips.
• Back up your workouts to a file and restore them on iPhone or iPad — including workouts saved from Caynax HIIT.

WHAT IS HIIT?
High-intensity interval training alternates short, intense effort with less-intense recovery. A typical session lasts 9-20 minutes: a warm-up, six to ten hard reps separated by easy recovery, then a cool-down. A common protocol uses a 2:1 work-to-rest ratio — 30-40 s hard, then 15-20 s easy. It is one of the best ways to get a complete workout when time is short.

Because of the intensity, this training is not for everyone. Please consult a doctor and a qualified trainer first.

PERFECT FOR: Tabata • HIIT • cardio • CrossFit-style circuits • Fartlek • kettlebell • jump rope • bodyweight • running intervals • boxing rounds • stretching • yoga • and anything else that needs a flexible timer.

FREE vs PRO
Caynax HIIT is free and fully usable: unlimited workouts, work up to 3 min, recovery up to 5 min, 1-20 rounds, voice and sound cues. PRO unlocks intervals of any length, up to 60 rounds, all spoken texts, your own sounds, the advanced countdown options, live heart rate, and History and Performance for good. Optional one-time PRO purchase, no subscription — plus a cheaper "remove ads" option if that is all you want.

Download Caynax HIIT and turn any space into your interval gym.