A lot of exercise will break down muscles. Tennis is the whole body strength, which relies on the power chain to produce whipping effect to hit the ball muscles that do not depend on the arm. Moreover, tennis mainly depends on the legs, not the arms, and the legs are in place.
Because tennis is not played with arms, but with a whip. The function of the arm is this whip. The thickness of the whip has little effect on the speed of throwing the whip head, so the thickness of the arm is not important in tennis. This sport is far from the understanding of ordinary people, basically the opposite.
Because in tennis, there is not much demand for abdominal muscle strength, so players will not focus on it. As for abdominal muscles, first, it is related to fat content, and second, it will be more or less involved in daily physical training with equipment, so it will naturally be there. Tennis players also have great abdominal strength, and core strength is very important for tennis. But whether abdominal muscles are obvious or not has nothing to do with the strength of abdominal muscles, but depends on fat.
Many people underestimate Federer's physical fitness. I think his physical quality is definitely the best among tennis players. Look at the four figures. Who is the most like a tennis superstar? I think it's Federer. Murray is too tall and Deyo is too thin. I think Deyo's biceps are similar to Federer's forearms, Nadal's muscles are too big, and Federer has the best figure. Symmetrical figure, excellent core, strong lower limb strength, thick forearm, not too much muscle mass, and no excess fat. His forearm would be perfect if it had less hair.
Generally speaking, it is the excellent physical quality, talent, playing style and excellent team that makes Federer still coquettish. On the other hand, Deyo on the grass, Nadal, Tim and Deyo on the red soil, Wawrinka and Deyo on the hard ground, and some explosive new generations are all great threats to Federer now.