yes, but really just on big max attempts... i havent used one for about a month or so, i think i remember cracking one when i pulled 525, but if i remember right i didnt when i pulled 535...
honestly im not very knowlegable on how they effect your body in detail, i just know they are only reccomended for big PR's... i did see stars on my first pull with 495 today... i continued without one, even going heavier and the stars didnt come back...
getting off topic a bit, but i was talking to an older guy today about seeing stars and he mentioned that it was (according to his doctor) a very minor form of a stroke... but absolutely nothing to worry about... but i will be researching that shortly... just threw that in as its been on my mind today...
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