Ramp4x4: VO2 Max Trainer

Run the Norwegian 4x4 with live heart-rate coaching, haptics, and clear Apple Watch cues. Understand workout quality and follow VO2 max trends over time.

Train your VO2 max with the Norwegian 4x4 - guided on iPhone and Apple Watch.

Ramp4x4 loads the complete session, cues every phase, coaches your heart-rate target, and shows what the workout delivered. Focus on the effort instead of building nine timer phases or doing zone math mid-interval.

THE NORWEGIAN 4x4, READY TO RUN

• One tap loads the warmup, four 4-minute work intervals, active recoveries, and cooldown
• Clear phase changes, countdowns, voice cues, and haptics
• Live heart rate against your personal VO2 target range
• Choose Apple Watch, AirPods Pro 3 or Powerbeats Pro 2 through Apple Health on supported devices, a compatible Bluetooth heart-rate monitor, or Timer Only

KNOW IF THE SESSION HIT THE TARGET

• Time in your VO2 target range
• Effective high-intensity time across all four intervals
• Peak and average heart rate, recovery, pacing, and completion
• A clear workout-quality score with practical coaching notes

TRAIN ON APPLE WATCH

Feel every transition on your wrist and see whether you are below, inside, or above your target. Run the Watch app when your iPhone is unavailable, or mirror the workout on iPhone and save the session to your history.

USE THE CARDIO YOU ALREADY DO

Run outdoors, or train indoors on a treadmill, bike, rower, elliptical, stair climber, or SkiErg. Ramp4x4 coaches your heart-rate target and measures workout execution. Indoor workouts do not update Apple Cardio Fitness, and Apple may not create a new estimate after every eligible outdoor activity.

FREE

• Unlimited classic Norwegian 4x4 workouts
• Apple Watch execution, voice cues, and haptics
• Live heart-rate coaching from supported sources or Timer Only
• Apple Health workout saving, your latest Apple Cardio Fitness estimate, achievements, weekly count, and a basic summary

PREMIUM

• The complete guided 8-week plan with progress interpretation
• Full workout history and detailed interval, target, recovery, and quality breakdowns
• Full Apple Cardio Fitness trend history, workout comparisons, and deeper training trends
• Custom interval presets and deeper coaching insights

Ramp4x4 is a training tool, not 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/