the answer is a because he is getting in shape which is making it easier for him
Answer
The component he has probably added to his training is A. running every other day.
Explanation
Everyday exercises will prepare a racquetball player with the strength required to quickly move up and down a court. The game requires a player to be flexible to enable him or her efficiently swing with the racquet without interference. This calls for a well shaped body that could be attained through physical exercises such as simple workout.