Double opposition: coordination, spatial judgment, and the rest are the same as above.
Serve: the jumping ability of abdominal muscles, deltoid muscles, chest muscles, forearms and legs, and the most important thing is coordination.
Every muscle in tennis should be connected, and the most important muscles in the upper body are forearm muscles and abdominal muscles. Forearm muscles are what we usually call the source of wrist strength, which ensures the stability of grip. Forearm muscles are mainly small muscles, so they are usually practiced after muscle exercise.
Abdominal muscles are the strength muscles for our waist-turning exercise. The forehand strength of tennis comes from the arm and waist. Usually, people with weak strength can't hit the ball deep by arm strength alone, which does not pose a threat. At this time, it depends on the strength of the waist. People with sufficient strength can reduce the burden on their arms by relying on waist strength to play ball, so that their arms will not be weak too quickly.
Every muscle in the lower body should be practiced. There is a famous saying in the tennis world that tennis is played with feet, which shows the influence of playing with all lower limbs. The exercise of lower limb muscles should be combined with speed exercise to improve the moving speed of your feet. I recommend you to practice running with Haining. Playing tennis is the key, and Nadal's excellent defense is his movement.
I hope what I said is helpful to you.