HIIT Pro: Interval Timer

Train with precision, not just a countdown. HIIT Pro is a customizable interval timer for iPhone and Apple Watch. Build workouts for HIIT, Tabata, running, cycling, rowing, circuits, boxing, EMOM and more. Follow clear cues, monitor your heart rate and match your music to every interval. HEART RATE ZONE TRAINING See live heart rate from Apple Watch, follow five customizable zones and set heart rate targets for individual intervals. Zone-colored graphs show your effort in real time, while post-workout insights reveal exactly how long you trained in each zone. BUILD WORKOUTS YOUR WAY Create unlimited workouts using warm-up, work, sprint, recovery and cool-down intervals. Add targets for heart rate, speed, power, RPM, resistance, reps or perceived effort—or start quickly with ready-made HIIT and Tabata templates. SPOTIFY WORKOUT MUSIC Assign Spotify tracks to specific intervals or connect an entire playlist to a workout. Control playback without leaving your training screen and keep high-energy music aligned with your hardest efforts. APPLE WATCH INTEGRATION Monitor heart rate and active calories, control your workout from your wrist and receive haptic interval alerts. Completed sessions can be saved to Apple Health and contribute to your activity history. WORKOUT HISTORY AND INSIGHTS Review detailed interval results, heart rate charts, calories and time in zone. Explore your consistency using month, year and multi-year workout calendars. Records, saved workouts and preferences can sync securely through iCloud. OPTIONAL BREATHING GUIDANCE Add paced breathing to an entire workout or selected intervals. Choose from resonance breathing, box breathing, 4-7-8 and equal breathing patterns. DESIGNED FOR FOCUSED TRAINING Use distraction-free Focus Mode, configurable countdowns, preparation alerts, quick time adjustments and max-heart-rate warnings to stay in control. No account or subscription required. Your health information remains under your control in Apple Health and iCloud. Spotify features require Spotify Premium and an internet connection. Apple Watch is optional but recommended.