Final answer:
Heritability accounts for about 40-50% of the VO2 max variability in sedentary adults, meaning genetic factors significantly influence individual differences in cardiovascular fitness among those who are not physically active.
Step-by-step explanation:
Heritability is a measure that shows the extent to which individual differences in a population can be attributed to their genetic difference. It is often expressed in percentages and specifically for VO2 max, which stands for maximal oxygen uptake and is a measure of cardiovascular fitness, heritability plays a significant role in determining individual variability, especially in sedentary adults.
While the exact percentage can vary from one study to another, a commonly accepted estimate is that heritability determines approximately 40-50% of VO2 max variability in sedentary adults. This implies that the genetic makeup of an individual can explain about half of the difference in VO2 max levels among individuals who do not regularly engage in physical activities.