What percentage of VO2 is related to genetics versus training?

• A. 60-70% genetic; 30-40% training
• B. 50% genetic; 50% training
• C. 30-40% genetic; 60-70% training
• D. 60-70% training; 30-40% genetic

Answer: (D)

VO2 max is shaped by both biology and training, but the training you do has the larger impact on the actual value you achieve. Genetics set your baseline and ceiling—some people are predisposed to higher oxygen delivery and utilization. Yet endurance training drives major adaptations that directly boost VO2 max: the heart becomes able to pump more blood per beat, the muscles grow more capillaries, mitochondrial density and oxidative enzyme activity rise, and the muscles become more efficient at using oxygen. Because these training-related changes account for a larger portion of how high VO2 max climbs across individuals and as a result of training, the typical view is that training explains about 60-70% of the variation, while genetics accounts for roughly 30-40%.