According to Phillips, the workout this machine offers can be hazardous since it tends to exert too much pressure or torque on the back of the kneecap, which can lead to early-onset arthritis. He recommends executing straight leg raises as a much safer alternative to leg extensions. This move requires you to lay flat on your back and raise one leg at a time. Because the SLR doesn't apply torque to your kneecaps, you won't need to be concerned.
Avoid deep or heavy squats for the benefit of the health of your knees. This action may damage the cartilage that covers your knees and place undue strain on your knee joints. According to Phillips, "Deep refers to sinking down extremely low, whereas heavy refers to any additional weights you may be carrying." Both are difficult to kneel on.
Plyometric exercises and harsh landings when leaping up and down might prematurely wear down the meniscus and cartilage in your knees. According to Phillips, "this exercise puts additional stress on the soft tissue, including the tendons and ligaments in the knee." These ligaments and tendons grow less flexible and more vulnerable to injury as we become older.
Sprinting is another workout that is too demanding on your knees after the age of 50, which shouldn't come as a huge surprise. It's a high-impact exercise that overstresses the nearby soft tissue around your knees. Additionally, it can put an excessive amount of strain on your cardiovascular system, which can be very risky.
"Lunges put stress on the patella (kneecap) and the surrounding tissues," Phillips explains. "A split squat is a safer substitute. With less stress on the soft tissues than a lunge, this exercise is excellent for strengthening and supporting the improvement of your balance as you age.