Final answer:
Genetics influences the training response, and 'high responders' to endurance exercise training can improve their VO2 max by up to 50%
Step-by-step explanation:
Genetics influences the training response and can significantly impact how much VO2 max can be improved with training. Some individuals are considered 'high responders' to endurance exercise training, and they can improve their VO2 max by as much as 50%.