I will third the notion of the lovely Princess L and the masked avenger DontKnowIt, both are resistance training. Of course there are different degrees of resistance which the muscle meets, when ever using a BowFlex or general weight training. BWT exercise are also resistance exercise, which a lot of people tend to forget. You friend does have a different genetic response to resistance training, as you do. Same diet, different diet or whatever..not the same muscle building/fat loss responses. I would guess a lot of the top Pro's would still look outstanding (though not any where near their full potential) if the BowFlex was the only piece of equipment ever used by them. Good Luck.