Peak Intervals vs PeakInterval

Peak Intervals helps you train VO₂max using the Norwegian 4x4 interval method and track training quality over time. Run, ride, or row a 4x4 session, stay in your target heart rate zone, then review clear metrics that explain workout quality and progress over time. What you get: • Guided 4x4 workouts with Apple Watch support • Target heart rate zone guidance based on 90–95% of estimated HRmax • Time in Zone (≥90% HR) to measure intensity • Repeatability to see if you hold performance from interval 1 to 4 • Recovery to measure how fast your heart rate drops between intervals • Trends and simple verdicts like Improving, Stable, Under-target, or Fatigued • Workout history with interval breakdowns and session details Apple Health Peak Intervals can read workout and heart rate data from Apple Health (HealthKit) to compute your metrics and trends. You control what is shared at any time in iOS Settings. Subscriptions Peak Intervals offers an auto-renewing subscription with monthly and yearly plans, including a 2-week free trial where available. After the trial, an active subscription is required to start new workouts. Payment is charged to your Apple ID account at confirmation of purchase. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. You can manage or cancel your subscription in App Store account settings. Peak Intervals is not a medical device and does not provide medical advice. High-intensity exercise may not be appropriate for everyone. Consult a physician before beginning a new training program. Privacy Policy: https://peakintervals.app/privacy Terms of Use: https://peakintervals.app/terms

PeakInterval is a clean, focused interval timer for every kind of training — from gentle Japanese walking to all-out HIIT. Set it, start it, and just move. Clear audio, spoken zone names and haptic cues keep you on pace so you never have to look at your screen. WORKOUTS FOR EVERY GOAL - Japanese Walking — alternate brisk and easy paces (beginner, classic and advanced) - Classic HIIT — 40 seconds on, 20 seconds off - Tabata — the original 20/10 protocol - Run/Walk and Sprint Intervals - Focus 25/5 — for deep-work blocks, not just workouts - Mobility Flow — an easy moving stretch BUILD YOUR OWN Use Quick Build to generate a repeating work/rest pattern in seconds — set your work and rest zones, rounds, and optional warm-up and cool-down. Or fine-tune every interval by hand. Your custom timers are saved under My Timers, ready whenever you are. CUES THAT KEEP YOU MOVING Every zone gets its own distinct sound — rising tones for effort, falling tones for recovery, ticks for the final three seconds, and a fanfare when you finish. Zone names can be spoken aloud, and haptics buzz on every change. It all plays over your own music and respects the toggles in Settings. LIVE ACTIVITY + DYNAMIC ISLAND When a workout starts, a live banner appears on your Lock Screen and in the Dynamic Island — showing the current zone, a self-updating countdown, your progress and what's next. No need to unlock your phone mid-set. APPLE WATCH APP Start, pause, skip and stop workouts right from your wrist, with haptic cues on every zone. Browse the same built-in workouts and your custom timers, synced from your phone. TRACK YOUR PROGRESS See lifetime stats — total workouts, minutes trained and your current day streak — plus a log of every finished session. PRIVATE BY DESIGN Everything stays on your device. No account, no sign-up, no data collection, no ads. Requires iOS 17 or later. Apple Watch app requires watchOS 10 or later.