# does apple watch track vo2 max — Wearable Metrics Explained > Updated: 2026-05-15 · Source: https://dorsi.ai/topics/does-apple-watch-track-vo2-max Yes, the Apple Watch tracks VO2 max — but it’s an estimate, not a lab-grade number. Starting with Series 3, Apple added optical sensors and GPS to… Yes, Apple Watch tracks your VO2 max. It calls it Cardio Fitness, and it’s an estimate—not a lab-grade measurement. The watch uses your heart rate and movement during outdoor walks, runs, or hikes to calculate it. The number can drop if you skip workouts or gain weight. Dorsi helps you see how your daily choices affect that score. On this page, I’ll break down exactly how the watch measures it and what you can do to push it higher. Yes, the Apple Watch tracks VO2 max — but it’s an estimate, not a lab-grade number. Starting with Series 3, Apple added optical sensors and GPS to calculate what they call Cardio Fitness (a VO2 max range). The watch uses heart rate, pace, and your profile data during outdoor walks, runs, or hikes. That’s good enough for a trend check, especially when you pair it with a dedicated strength coach like Dorsi. Those three Apple Watch numbers we’ve written about — resting heart rate, heart rate variability, and recovery — actually tell you more about training readiness than a single VO2 max snapshot. So what does the number really mean for your workouts? Let’s break down how the estimate is built, where it falls short, and how to use it without overthinking. ## Check your Apple Watch VO2 Max setting Open the Watch app on your iPhone, go to My Watch > Workout > VO2 Max, and make sure it's enabled. If it's off, toggle it on. This setting allows your watch to estimate your cardiovascular fitness during outdoor walks, runs, and hikes. Without it, no data gets logged. ## Complete a qualifying outdoor workout VO2 max estimates require a sustained outdoor workout of at least 20 minutes. Start a Walking, Outdoor Run, or Outdoor Hike workout on your watch. Walk or run at a steady pace—the algorithm needs consistent heart rate and GPS data. Stop-and-go activities like interval sprints won't trigger a reading. ## View your VO2 max in the Health app After a qualifying workout, open the Health app on your iPhone. Tap Browse > Heart > Cardio Fitness. Here you'll see a graph of your estimated VO2 max over time. Each dot represents a workout where your watch calculated the value. Tap a dot to see the exact number and the date it was recorded. ## Interpret your cardio fitness level Apple Watch classifies VO2 max into low, below average, above average, high, or very high based on your age and sex. Values are measured in mL/kg/min—higher numbers mean better aerobic capacity. For example, a 30-year-old male with a VO2 max of 40 is in the low range. Use this to gauge your fitness trend over months. ## Use Dorsi to improve your VO2 max Want to lift that percentile? Run an adaptive strength program—VO2 max responds to heavy compound lifts and high-rep circuits. Dorsi plans load, sets, and rest for your max, not a generic split. Check it on iOS after a week of serious squats: that number should climb. ## FAQ ### does apple watch measure vo2 max accurately Apple Watch uses heart rate and motion data to estimate VO2 max during outdoor walks, runs, or hikes. Accuracy is decent for fitness tracking but not clinical-grade. Studies show reasonable correlation with lab tests for moderate activity. For casual use, it's a useful trend indicator, but don't rely on it for precise medical assessment. ### how to set up cardio fitness on apple watch Open the Health app on iPhone, go to Browse > Heart > Cardio Fitness. Tap "Set Up" and follow prompts. You'll need to allow notifications when your fitness level is low. Ensure your Apple Watch has recorded at least a few outdoor walks or runs. The feature works automatically after setup – no extra watch app needed. ### what is a cardio fitness score Cardio fitness score is Apple's term for VO2 max estimate, measured in mL/kg/min. It indicates how efficiently your body uses oxygen during exercise. Higher scores mean better cardiovascular health. Apple classifies levels as Low, Below Average, Average, Above Average, or High, based on age and sex. It's a useful metric for tracking changes. ### why is my vo2 max below average A below-average VO2 max could be due to sedentary lifestyle, aging, or health issues like obesity or heart conditions. It might also drop if you haven't exercised enough outdoors with sufficient heart rate data. Check watch fit and ensure outdoor walks or runs. If consistently low, consider a doctor – but first verify setup is correct. ### what does apple watch count as exercise Apple Watch counts any movement lasting at least a minute that raises heart rate above a threshold – walking, running, cycling, swimming, etc. It auto-detects workouts for common activities. The "Exercise" ring tracks minutes of brisk activity (≥3 METs). Manual workouts contribute too. Standing counts only if you move enough within the hour.