i have the same problem bro....yesterday when i was working out i had to cut it short becasue after i did one set of close grip bench my right tricep muscle cramped up and i was in a bit of pain....i also could not extend my right arm....im only doing clen right now......it has also happened to me in the past as well...i dont know for sure if its from the clen but this kind of thing always happens to me when im taking it.