Running is great for your legs and the rest of your body
You are exercising with the stationary bike. For a weight-bearing exercise, you could alternate the bike with at least a half an hour of walking or some jogging. Depending upon your surroundings and weather conditions, you can walk indoors from room to room and/or up and down stairs, if necessary.
Steps and stairs are the best! If you have stairs in your home or building.. go up and down as long as you can! (be careful tho- you don't want to fall)!