the results are good I feel! I train fairly regular with the mask. usually Kettle bells and my homemade TRX straps type stuff. I can tell a huge difference if I've gotten to use the mask consisitently. About 3 times a week. I havent used the O2 trainer in quite a while, but I also swim with a snorkel alot because I have a PT test for work and its sort of the same only with a bigger hole to breath through. But when I train consistently I do feel like my cardio as far as rolling is better.