N4x4 vs VO2Max Training

The best Norwegian 4x4 App on the App Store. Train the Norwegian 4x4 without watching the clock or guessing your effort. N4x4 reads your live heart rate — from Apple Watch, AirPods Pro 3, Garmin, WHOOP, Polar, or any Bluetooth monitor — and turns it into clear push, hold, and ease-off cues through every interval. When you finish, you see exactly how long you held the target zone, and how today compared with last time. Four 4-minute efforts, three easy recoveries. 33 minutes, warm-up and cooldown included. It trains VO2 max, the fitness marker most closely tied to how well you age, and it's one of the most studied ways to raise it. If you're going to invest time in your health, this is a strong place to start. HIT THE RIGHT ZONE • Target zones calculated from your own max heart rate • The number turns orange when you're below the zone and red when you're above, on both iPhone and Apple Watch • Spoken and haptic nudges when you drift out and stay out • A haptic countdown into every interval change: two taps, then the buzz USE THE SENSOR YOU ALREADY OWN • Apple Watch: install N4x4 on your wrist and heart rate streams automatically • AirPods Pro 3: the earbuds you're already wearing double as your heart rate monitor (iPhone on iOS 26) • Garmin (Broadcast Heart Rate), WHOOP (HR Broadcast), Polar, Wahoo, COROS, Powerbeats Pro 2, and any standard Bluetooth chest strap or armband • Wearing more than one? You choose which source wins • A built-in guide with exact, per-model setup steps EASY TO KEEP THE HABIT • Voice coaching through every interval, with the phone locked and your music ducked • Night-before, morning-of, and comeback reminders — each on its own switch • Weekly streaks, and a Live Activity on the Lock Screen and Dynamic Island FINISH WITH PROOF • Every interval charted against its target zone • Time in zone, time to zone, and a note per interval for your settings • Last session laid over today's, so progress is easy to see • Your usual workout — Cycle, Run, Kettlebells, and more — pre-selected when you save SEE THE PAYOFF • Your VO2 max trend from Apple Health • Training calendar, milestones, and full session history Works on the treadmill, rower, bike, stair climber, with kettlebells, or on the open road — any cardio that gets your heart into the zone. No account. No subscription. No ads. Your data stays on your device and in Apple Health. Start with one hard session a week. Add a second when you're ready.

VO₂Max is the strongest predictor of how long you'll live. Now you can actually improve it. If you've read about VO₂Max in longevity research or seen it on your Apple Watch, you know it matters. But knowing your number isn't enough—you need structured training to improve it. VO₂max Training is built natively for iPhone and Apple Watch: science-backed protocols, a guided session timer, progress tracking, and AI insights—so you can train with purpose and see real cardiovascular gains. A SPECIALIZED TRAINING APP FOR THOSE WHO CARE No more web wrapper. VO₂max Training is rebuilt as a true iOS experience with dedicated tabs for training, tracking, and insights—faster, smoother, and designed for real workouts on your phone and watch. TRAIN — STRUCTURED VO₂MAX WORKOUTS • Browse research-backed protocols (Norwegian 4×4, Tabata, Zone 2, and more) • Follow guided interval sessions with work/rest timing, pause, and skip • Build training plans with simple or advanced plan builders • Customize workouts with the interval builder and preview sessions before you train • Log post-workout heart rate and notes when you finish • Earn badges as you build consistency APPLE WATCH & LIVE COACHING • Start and control workouts from your Apple Watch • See live heart rate on your iPhone during sessions • Stay on pace with segment guidance and haptic cues • Follow your session on the Lock Screen with Live Activity • Train with confidence in the right intensity—not too easy, not too hard TRACK — SEE YOUR PROGRESS • Review session metrics and workout history • Monitor weekly metrics and training load over time • Connect Apple Health to enrich your data • Export your training history when you need it • Add a Home Screen widget for Resting Heart Rate and VO₂ Max INSIGHTS — TRAIN SMARTER • Get personalized cardiovascular insights based on your training data • Understand trends in your fitness and recovery with clear, actionable analysis • Unlock deeper cloud-powered insights with VO₂max Premium RESEARCH-BACKED PROTOCOLS Every protocol is grounded in peer-reviewed exercise science and designed specifically for VO₂max improvement—not random workouts. AI-POWERED GUIDANCE Our insights adapt as you improve, helping you understand what's working and what to focus on next—grounded in your data and the latest exercise science. WHO IS THIS FOR? VO₂max Training is for health-conscious adults who know cardiovascular fitness is foundational to longevity. If you're already exercising and want to train smarter—not just harder—this app is for you. GETTING STARTED • Complete quick onboarding to set up your profile and get a protocol recommendation • Sign in with Apple, Google, or email • Pick a protocol, start a guided session, and track your progress over time • Connect Apple Watch for live heart rate during workouts VO₂MAX PREMIUM Upgrade for unlimited training sessions, advanced AI insights, and full access to planning tools. Try Premium free for 1 week—cancel anytime. WHY VO₂MAX MATTERS VO₂Max measures your body's ability to use oxygen during exercise. Research shows it's one of the strongest predictors of longevity—more predictive than many common risk factors. Each meaningful improvement in VO₂max is associated with better cardiovascular health and long-term independence. You can't improve what you don't know how to train. We make VO₂max improvement accessible. Start training for longevity today. Terms of Use (EULA): https://vo2max.app/terms Privacy Policy: https://vo2max.app/privacy