What factor influences VO2max significantly, with a contribution of up to 80%?

Hereditary factors have a significant influence on VO2max, contributing up to 80% to an individual's maximal oxygen uptake. Genetic predisposition can determine various physiological characteristics, including heart size, lung function, muscle fiber composition, and the efficiency of the cardiovascular and respiratory systems, all of which are crucial for determining aerobic capacity. This means that individuals with a favorable genetic makeup may naturally possess a higher VO2max than those without such traits, independent of their training status or lifestyle choices.

While age, exercise mode, and environmental factors can also impact VO2max, their contributions are generally less decisive compared to hereditary factors. Age typically leads to a decline in VO2max, but this is a gradual change influenced by lifestyle and training rather than a fixed genetic characteristic. Exercise mode can influence how VO2max is expressed or measured but does not fundamentally change the underlying genetic potential. Environmental factors, such as altitude or temperature, can have acute effects on performance but again do not dictate the inherent capacity that genetics provides.