What sports do you exercise without knees?
If the medial meniscus is injured, rest first, because it can recover on its own. When you feel no discomfort, you can take part in exercise. Relatively speaking, swimming is the best. The buoyancy of water can help you offset the pressure of gravity on your knees, so swimming is the best. Bicycles are better than treadmills. It is not recommended to do more.