Changing your diet will not potentially cause you serious physical harm; preventing a diabetic from having the appropriate diet will. Sorry, but your weight training isn't a medical issue.

Yes, the medical exemption is a huge and glaring hole. It serves to show how ridiculous the entire system is. Still, none of us are in a position to suggest that someone's medical needs are illegitimate, nor should we be.

Moreover, the TSA can run an ETD on the bottle and determine that it isn't explosive, so there is no real risk, just a bit of extra time required brought on by a ridiculous policy implemented despite a lack of credible evidence that a threat vector exists and despite the fact that a number of other countries have managed to source the appropriate hardware to ovbiate the ban, even if the threat were credible.