What sports are you good at?
There was a famous Olympic speed skater, I think it was Eric Heiden, who won gold medals on the ice and then became a professional bike racer. He had to lose a lot of the muscle in his thighs to be competitive on a bike. IIRC it took well over a year.
Professional bike racing teams have determined a range of power to body weight ratio that will win on mountain stages and the massive thigh muscles that speed skaters have just don’t pay off for racing up a mountain.
As for my sport, while I prefer bike riding or running (back when my knees were better) I’m not good enough at cycling to race or anything. When I was junior high school age 55 years ago, my big brother got a set of barbells and I noticed I could build my thigh muscles far easier than my arms or upper body. I guess that’s genetics