HIIT Timer vs VO2 Max Trainer

Interval Flex: Advanced Interval Timer Create complex interval sequences that simple timers can't handle. Perfect for HIIT workouts with group repetitions, breathwork patterns like 4-7-8 breathing, and pyramid training routines. Why Choose Interval Flex: - Complex Patterns: Group intervals and repeat sections - ideal for boxing rounds, Tabata circuits, and breathing exercises - Smart Grouping: Set up sequences like "warm-up, then repeat high-intensity/rest 5 times, then cool-down" - Breathwork Templates: Pre-built sequences for 4-7-8 breathing, box breathing, and custom patterns - Template Library: HIIT, Tabata, pyramid workouts, and meditation timers ready to use - Visual Feedback: See which intervals are grouped and how many repetitions remain - Multisensory Alerts: Sound, vibration, and visual cues for seamless transitions Perfect For: - Complex HIIT workouts with grouped intervals - Breathwork and meditation sequences - Tabata training with custom rest periods - Pyramid interval training - Any timing pattern simple apps can't create Built for users who need more than basic 30-second/10-second timers. If you've been frustrated by simple interval apps, Interval Flex gives you the flexibility to create exactly the sequences you need. Download now and build the perfect timer for your routine!

Boost your VO2 max, one of the strongest predictors of endurance performance and of how long and how well you live. Measure your true VO2 max in 15 minutes or less, raise it with Zone 2 and HIIT workouts, and beat the rest of the world on a verified global leaderboard. iPhone and Apple Watch. NEW: GHOST RACE Race a ghost during your Cooper test, Balke test or 1.5 mile (2.4 km) run. Pick your best run, your 12-week goal, the athlete 10 places above you on the leaderboard, the #1 of your age group, an Olympic record, or any VO2 max you choose. The gap shows live in meters or yards, green when you lead and orange when you chase, with voice cues when you pass or get passed. Follow the race on the Lock Screen, in the Dynamic Island and on your Apple Watch, even without your iPhone. The result saves as a normal test, and you can share a "Me vs ghost" card. MEASURE YOUR VO2 MAX - Beep test 20 m and 15 m (bleep test, PACER test, multistage fitness test, Leger shuttle run) - Yo-Yo Intermittent Recovery test, levels 1 and 2 (YYIR1, YYIR2) - Cooper test (12-minute run) - Balke test (15-minute run) - 1.5 mile / 2.4 km run test Results are compared with age and sex norms. FIND YOUR TRUE MAX HEART RATE AND LACTATE THRESHOLD The 220 minus age formula can be off by 10 to 20 beats per minute. Run a beep test with a heart rate monitor and the app records your real maximum heart rate and estimates your lactate threshold from how your heart rate responds as the pace rises, with no lab and no blood test. Your Zone 2 and HIIT zones are then built from your own threshold. TRAIN TO IMPROVE IT - Zone 2 training with personal heart rate limits and Apple Watch haptics when you drift out of zone - HIIT and interval workouts: Norwegian 4x4, Tabata, Gibala, 30/30, EMOM, Myoreps - Free mode to log any session - Custom workout builder: work, rest, repeat blocks, warm-up and cool-down - A 12-week training plan built from your current fitness level - An AI coach on the Plan tab that tells you what to do today and why GLOBAL LEADERBOARD WITH VERIFIED RESULTS Compare your VO2 max with athletes worldwide by age, sex, country and job. A score only reaches the leaderboard after anti-cheat checks: GPS, heart rate (Apple Watch or a chest strap), cadence and vehicle detection. Verification badges show how each result was checked. O2 POINTS AND RANKS VO2 max moves slowly, so O2 Points show the work you put in every day. Every minute with heart rate earns points, harder zones earn more, and 80/20 training, following your plan and retesting give boosts. Climb 7 ranks, from Reserve Duty to Norwegian Cyborg. LIVE ACTIVITIES AND WIDGETS Every test, Zone 2 session and interval workout shows on the Lock Screen and in the Dynamic Island: level, time, heart rate and zone without unlocking. Home Screen and Lock Screen widgets show your next workout, readiness, fitness age, VO2 max progress, Zone 2 minutes, O2 rank and leaderboard position. KNOW YOUR BODY - Training readiness score (1 to 100) from HRV, resting heart rate, sleep and recent load - Fitness age, from your VO2 max and other health markers - Race time predictions from 5K to marathon - Post-workout analysis: effort score, time in each zone, pace, intervals - Editable history with monthly and yearly charts APPLE WATCH AND HEALTH Leave the phone at home: tests, Zone 2 and intervals run on the watch with haptics and audio. Workouts sync with Apple Health, and workouts from other apps can be imported. WHO IT'S FOR Athletes and runners who want to go faster for longer. Soccer, rugby, basketball and hockey players. People preparing for military, police or firefighter fitness tests, PE teachers, students and coaches. And anyone who wants a stronger heart and lungs, a younger fitness age and more healthy years. Built by one independent developer. Questions? Message me in the app. Terms of use (Apple standard EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/