VO₂ Reserve Calculator
Find your VO₂ reserve and the training zones built on it, the method ACSM uses to set intensity.
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Enter your VO₂ max.
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What VO₂ Reserve Means
VO₂ reserve is the gap between your resting oxygen use and your maximum. ACSM uses it to set exercise intensity more precisely than raw percentages of VO₂ max.
Effort and heart rate map neatly onto your training zones.
Resting oxygen use is a steady 3.5 ml per kilogram per minute, known as one MET.
Training zones then take a share of that reserve.
How to Use This Calculator
- Enter your VO₂ max. The VO₂ Max tool can estimate it.
- Tap Calculate for your reserve and zones.
The Formula Used
VO₂R = VO₂ max − 3.5
Zone = 3.5 + VO₂R × intensity %
Zone = 3.5 + VO₂R × intensity %
- VO₂ max
- Your peak oxygen use.
- 3.5
- Resting oxygen use, one MET.
Understanding Your Results
Light
30-40% VO₂R
Easy recovery work.
Moderate
40-60% VO₂R
Steady aerobic training.
Vigorous
60-85% VO₂R
Hard, fitness-building effort.
Near max
Above 85% VO₂R
Short, intense intervals.
Tips to Improve
- Spend most time in the moderate band.
- Use brief vigorous intervals to build capacity.
- Recover fully between hard sessions.
- Re-estimate VO₂ max as fitness changes.
Frequently Asked Questions
It accounts for resting metabolism, so the intensity matches effort more closely.
Use our VO₂ Max tool or a lab test for the input value.
They are similar ideas applied to oxygen and heart rate, and they track closely.
Scientific References
- American College of Sports Medicine. (2021). ACSM's Guidelines for Exercise Testing and Prescription (11th ed.).
- Swain, D. P., & Leutholtz, B. C. (1997). Heart rate reserve is equivalent to %VO2 reserve. MSSE, 29(3), 410–414.
- Garber, C. E., et al. (2011). ACSM position stand: Quantity and quality of exercise. MSSE, 43(7), 1334–1359.