Strengthening the knees can be effectively achieved through cross-training, including step workouts, which are less jarring than running. Incorporating exercises like leg lifts, squats, and lunges can enhance knee stability and strength, particularly for those recovering from injuries. It's important to gradually increase weights during strength training to improve bone density and overall knee health. Some participants noted that isometric exercises may not be beneficial and could contribute to issues like osteoarthritis. Overall, a balanced approach combining various forms of exercise is recommended for knee strength and injury prevention.