Well I have watched many you tube videos. Most of the people on there are half my age and much fitter. I'm 53 a recent below knee amputee haven't had good mobility for 20 years and for the last 2 years before amputation have barely walked at all. So it takes some effort and does not claim to give you the mobility and fitness that you did not have before. As someone waiting for their prosthetic this is a game changer. I have to use a stick with it as my legs are still weak. But those of us who are older and less fit than we once were can benefit hugely from these.