Ramp4x4: VO2 Max Trainer

Train your VO2 max with guided Norwegian 4x4 workouts on iPhone and Apple Watch. Four 4-minute efforts. Guided recovery. Live heart-rate coaching. Ramp4x4 handles the session so you can focus on your workout instead of setting up timers or calculating heart-rate zones. Start with unlimited classic Norwegian 4x4 workouts, or build consistency with a focused 8-week Premium plan featuring two sessions per week. THE NORWEGIAN 4x4, READY TO GO • One tap loads your warmup, four 4-minute work intervals, active recoveries, and cooldown • Follow clear countdowns, voice cues, and haptics • See whether your live heart rate is below, inside, or above your target range • Train with Apple Watch, AirPods Pro 3, Powerbeats Pro 2, a compatible Bluetooth heart-rate monitor, or Timer Only MAKE EVERY INTERVAL COUNT See how closely you followed your workout targets. Review time in your target heart-rate range, high-intensity time, interval completion, and recovery. Premium adds detailed interval breakdowns, workout-quality scoring, comparisons, and coaching insights to help you understand your session and prepare for the next one. BUILD CONSISTENCY WITH AN 8-WEEK PLAN Follow a guided Premium plan with two workouts per week. See your next session and weekly progress at a glance, review your performance, and approve suggested plan adjustments before they are applied. TRAIN ON APPLE WATCH Get heart-rate guidance and feel workout transitions on your wrist. Train with the Watch app when your iPhone is unavailable, or follow your session on iPhone. USE THE CARDIO YOU ALREADY DO Run outdoors or train indoors on a treadmill, bike, rower, elliptical, stair climber, or SkiErg. Follow the same interval structure and heart-rate guidance across your preferred cardio activities. FOLLOW YOUR CARDIO FITNESS View your latest estimated VO2 max from Apple Health’s Cardio Fitness data. With Premium, explore your available estimate history alongside workout trends, target time, working heart rate, and recovery. Ramp4x4 displays available estimates from Apple Health; it does not directly measure VO2 max. Indoor Ramp4x4 workouts do not generate Apple Watch Cardio Fitness estimates, and a new estimate is not guaranteed after every outdoor workout. FREE • Unlimited classic Norwegian 4x4 workouts • Apple Watch workouts, voice cues, and haptics • Live heart-rate coaching from supported sources, or Timer Only • Save completed workouts to Apple Health • Latest available Cardio Fitness estimate • Achievements, weekly workout count, and your latest workout summary PREMIUM • Complete guided 8-week training plan • Plan progress insights and suggested adjustments • Full workout history and detailed interval analysis • Target-range, recovery, and workout-quality breakdowns • Available Cardio Fitness trend history and workout comparisons • Custom interval presets and deeper coaching insights Heart-rate analysis requires a supported heart-rate source. Health data features require permission and available data. Ramp4x4 is intended for general fitness and wellness. It is not a medical device and does not provide medical advice. Build up gradually and speak with a clinician before near-maximal intervals if you have a health concern. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://rampworkout.com/privacy/