For recovery YAY but not building muscle. The latter requires exceedingly painful levels of ElectroStim (as tried many years ago by the Russians) or a 'shivering protocol' developed more recently by an Irish university (I could dig out the paper but it wasn't pleasant either, all of the researchers said that they'd much prefer to actually do the exercise than 'shiver' for long stretches).

SteveMc

I have one and use it periodically for recovery after a hard workout. I think there's a small but noticeable impact on recovery (then again, it may entirely be a placebo effect). If I had to make the choice again, I'm not sure I would spend the money on it but since I have it I use it. I can't see it being useful at all for building strength.

I found that if I use it before a race, my legs are zapped. Even recovery mode. I would use it for recovery only. Never had success with the strength mode doing any good. I have the Elite (wired) one. I primarily use the Active Recovery, Massage & Endurance modes. None of the others.

I bought one a few years ago when it was half price on Active....I have only used it for recovery and I would say it does help somewhat. I don't think it's worth the full price, though, so if you can get one half off, go for it.