Final answer:
Around 40% of VO2 max, the body enters the aerobic training zone, a good zone for increasing cardiovascular fitness.
Step-by-step explanation:
In biology, the concept of VO2 max refers to the maximum amount of oxygen that an individual can use during intense physical activity. At around 40% of VO2 max, the body enters the aerobic training zone, where the body is using a significant amount of oxygen to produce energy. This level of intensity is usually associated with low to moderate exercise.
For example, jogging or brisk walking would fall within this range. The body is able to sustain this level of exercise for an extended period of time without building up an oxygen debt. It is a good zone for increasing cardiovascular fitness.