Be sure to ride a bike, which may make your leg muscles more developed. . But it doesn't necessarily get thicker, but after you ride a bike, you should do some leg muscles properly. . Do it seriously. . The main thing is to stretch the muscles you exercise. . So your legs won't get thicker and uglier because of riding a bike. . Relaxation and stretching after exercise are very important. . I suggest you try spinning in the gym. . It feels so good.