How to Improve Your VO2 Max

Consistent aerobic exercise at the right intensity is the primary driver of VO2 Max improvement. Most people see gains of 5-15% over 6-12 weeks of structured training. The two variables that matter most are frequency and intensity. You need to train regularly, and you need to include some harder efforts alongside your easy sessions.

The Two Training Approaches That Matter

Zone 2 base training means long, easy efforts at 60-70% of your maximum heart rate. You should be able to hold a conversation comfortably. These sessions build mitochondrial density, improve fat oxidation, and strengthen your aerobic engine. They form the foundation of any cardio fitness program. Aim for 30-60 minutes, 3-4 times per week.

High-intensity intervals push your heart rate to 85-95% of maximum for short bursts, followed by recovery periods. A typical session might include 4-6 intervals of 3-4 minutes at high effort with 2-3 minutes of easy recovery between them. These sessions drive the largest acute improvements in VO2 Max because they force your cardiovascular system to work at near-maximum capacity.

The research supports a ratio of roughly 80% easy training to 20% high intensity for most people. This is often called polarized training. One or two hard sessions per week combined with several easy sessions produces better results than training at moderate intensity every day.

How Long It Takes

Beginners see the fastest gains. If you are starting from a low cardio fitness base, improvements of 10-15% over 8 weeks are common. That might mean going from 30 ml/kg/min to 34 ml/kg/min, enough to shift you from “Below Average” to “Average” for your age group. Use our VO2 Max percentile calculator to see your current standing and what improvement could mean for your ranking.

Already-fit individuals improve more slowly, typically 3-5% over the same period. Genetics set the ceiling, but most people are nowhere near their genetic potential. Consistent training over months and years produces compounding gains that are far more meaningful than any short-term sprint.

What Your Apple Watch Shows

Apple Watch estimates VO2 Max after outdoor walks, runs, and hikes. The reading updates gradually as your fitness changes, not after a single session. It uses heart rate, pace, and elevation data to predict your cardio fitness level. Indoor workouts, cycling, and swimming do not produce VO2 Max estimates on Apple Watch.

Luen connects your VO2 Max trend to your daily habits so you can see what actually moves the needle over time. Rather than checking a number in isolation, you see how your exercise, sleep, daylight, and stress patterns relate to your cardio fitness trajectory. Make sure your Apple Watch is actually capturing your progress — see how often it updates VO2 Max.

What Else Matters

Sleep quality directly affects your body’s ability to adapt to training. Your cardiovascular system builds fitness during recovery, not during the workout itself. Chronic poor sleep limits VO2 Max improvement even with a good training program. Aim for 7-9 hours of quality sleep. Training is only half the equation — sleep plays a major role in your VO2 Max as well.

Stress management matters because chronic stress elevates your resting heart rate and impairs recovery. If your resting heart rate is trending upward despite consistent training, stress or poor sleep may be the limiting factor.

Consistency over intensity. Three moderate sessions per week, every week, will outperform sporadic intense training. The adaptations that improve VO2 Max are cumulative and require sustained stimulus over months.