According to IHRSA, the leading trade association for the fitness business, the most popular aerobic machines are treadmills, stationary bikes, elliptical machines, stair climbing machines, rowers, and cardio cross trainers. We have all of those at The Training Station Gym, (except stair climbing machines). But which one is kind on bad knees?

You may need a physical therapist

aerobic machines

If your knees have lost their normal function, you should seek out a physical therapist to get you back to normal. Physical therapists use exercise and science to restore normal function. They know the best aerobic equipment to get you back to the way you were, or even if you should use aerobic machines to do so.

Finding the right aerobic machines, by trial and error

aerobic machines

If you’re out of physical therapy, or if your normal state includes painful knees, you’ll have to figure out which machines work for you. It will take some trial and error. Remember the following:

1. Walking on a treadmill creates ground reaction forces equal to 1.5 times your bodyweight. Running on a treadmill creates ground reaction forces equal to 3 times your bodyweight. Those kinds of forces may irritate knees.

2. The feet don’t usually leave the foot tray of an elliptical machine or an aerobic cross trainer, therefore the feet don’t land and they don’t produce significant reaction forces. You can set the incline to zero-height on some cross trainers, like our Cybex Arc Trainer. As a result, in addition to negligible ground reaction forces, there would also be negligible knee flexion. Under those circumstances, the knee joint would move very little even as you exercise. There’s a better-than-average chance that those circumstances won’t irritate the knee’s underlying problem.

3. Charles Tipton, the great American exercise physiologist, showed that incline running can strengthen the tendons and ligaments in the knee. If your knees are bad because of weak connective tissues, but good enough to allow you to run, then incline running may pay-off over time.