I'm 60 and in pretty good shape but I could not go for more than 3 minutes. My wife (53) couldn't do more than 2 minutes and it hurt her back enough so that I had to take her to the chiropractor. My athletic grandson did the best but even he had a hard time, so I sent it back. But get this, that cost me $360!. Free shipping refers to one way, there to you. Buyer beware.
Bottom Line: No, I would not recommend this to a friend