There are a lot of exercises you can do to improve leg muscles. I go to the gym 5 days a week and do a little bit of legs every day when I go. The stairmaster is great because it’s not only a good leg workout, but is also great cardio which really helps with riding. You can also do other things such as squats, leg press and calf rises. If you don’t have access to a gym, lunges are also a great way to build muscle. You can also simply go for a walk/ run, and other sports involving cardio (such as soccer) can really help build the leg muscles you will use while riding.