If you want to exercise your legs, you should practice sprinting and doing squats with barbells in the gym. Now we should practice for a day and rest for a day, so as to ensure that our muscles can get a full rest. Usually, you should eat more high-protein food to supplement your body needs. When exercising, you must do what you can, and don't hurt yourself, especially the barbell. Start with a low weight and don't rush to gain weight directly!