Tweeti have known one guy to die while squatting running slin pre so that was enough to keep me from giving it a go. perfectly healthy dude to in his late 20s. now as for post here is what i think: you are using slin for the purpose of adding muscle and such. it cause more nutrients and such to be forced into the muscles. now after we do the damage to our muscles through training them and then hitting the slin and hammering all the good stuff to fill the up is forced in even more with slin. so that leads me more so to feel like it is more of a benefit to use post workout which is what i choose to do. now with that said there are articles out there that point out the pros and cons of both but after knowing someone to die from it pre i dont roll that route