Q: I heard that the step machine is not very good for the knees. In fact, doing the step regularly (2 times a week) can cause major joint problems there...is this true?

A: As far as I know if you do not have any pre-existing knee conditions, the stair machine will not hurt them. An injury is always a possibility in general, both when exercising and in 'regular' life. If you do feel pain in the knee (or anywhere else) that shouldn't be there, STOP immediately! The only good pain is the muscle tiredness during the exercise and possible muscle soreness afterward. Any other kind of pain is not good. If it happens, stop exercising and see a doctor. But there's nothing inherently dangerous in the stair machine. Remeber to maintain proper posture when using the stair machine -- your torso should be upright and you should not put any weight on the rails, they're only their to make sure you don't fall.

I should add that women are much more prone to knee injuries than men due to their anatomy. But again, the stair machine is not any worse than other machines or forms of cardio. However if you have an existing knee (or any other) condition or think you may have one, please consult with your doctor and/or physical therapist before starting on a program.