I used to lift weights with some guys that took it as well. They always did seem to get bigger than everyone else. It's just a rumor, but I heard stuff like it can make your heart burst while your standing in the sun on a hot day. That is if you have been taking it a while. Just a rumor though.

*EDIT*
I think I remember someone telling me it works by letting your muscles hold more water, which increases the mass and let's your muscles be able to take more strain. The heart is a muscle. I don't mess with any stuff like that except for straight up protein.

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