As a pretty athletic kid for most of my life I've been rather sessile the past year or so (working 40 hours a week, taking 18 credits, other responsibilities, etc.) but I'm planning on getting back into shape now and I've been seeing the commercials for this stuff pretty consistently of late (perhaps because I'm getting back into the gym and I just happen to notice it more). I don't think I'd ever actually take any of these types of supplements as I'm kinda worried about what they'd do to my heart, but I'm just curious to know if anyone has ever used 'em and had any success. I've known kids in high school who used the stuff, but they were also playing football and weightlifting with me so it was hard to discern if this stuff did anything or if it was just the fact that we were always exercising.