I am at the stage in life where my knees are giving me problems, and I no longer run, or do marathons, so I need to find something that keeps me in shape. Over the last several years I have turned more to cycling, either on the road or on a stationary machine.

Many backpackers have "Nordic walked", for years, using two poles (adjustables are the best bet), but frankly my experience is that it doesn't really do that much to help the knees -there is still a lot of pounding. I am skeptical about the alleged benefits, compared to jsut getting out and putting one foot in front of the other.

Swimming is the ultimate for non weight bering aerobic exercise, but it just doesn't appeal to me.