What factor contributes to the gender difference in VO2 max values?

The factor that contributes to the gender difference in VO2 max values is lean muscle mass. VO2 max, which reflects the maximum amount of oxygen that an individual can utilize during intense exercise, is generally higher in males than in females, primarily due to physiological differences, including body composition. Lean muscle mass is directly linked to cardiovascular efficiency and the body's oxygen consumption capabilities.

Men typically have a higher percentage of lean muscle mass compared to women, which enhances their ability to perform aerobic activities effectively. Muscle tissue is metabolically active and requires more oxygen, thus increasing VO2 max. Additionally, higher levels of testosterone in males contribute to increased muscle mass and strength, which further influences aerobic capacity.

The options regarding body fat percentage, increased physical activity levels, and age do play roles in overall fitness and health, and they can affect VO2 max to an extent. However, the primary factor in explaining the baseline differences between genders in VO2 max is indeed the disparity in lean muscle mass.