I have never understood supersetting fully. I think one reason is I have a medical condition that makes my lung capacity maybe ~10% less than the average person. To get around it I try different breathing techniques, sometimes breathing and exhaling more than one breath a rep depending on the exercise.
Was in the Arnold's chest thread; saw that he used to superset chest and back with no rest according to a poster. Have seen some people in the gym do similar things. Some of them have very respectable physiques.
I guess my question is why does supersetting work?
I believe the answer is this: If you are going balls out, not stopping any or much at all between sets.. your body is just plain working harder to do the same amount of work. Case in point: If I decide to go big on an exercise, say 5 rep sets, and I wait 3 minutes between lifts, the exertion does not feel as bad for the 2nd set as it would if I ran around and did another exercise and came back. I can't scientifically understand this though. If I wait the 3 minutes, my muscles are ready to do the lift again and primed.. but they have had more time to rest. So maybe my heart rate went down, maybe blood is not gushing as hard around the muscle, adrenaline has slowed, etc.
So why does supersetting work? I need an answer that really makes sense so I can quit avoiding a potentially valuable lifting technique for my arsenal.
EDIT: Pumpster has a thread going about rest periods that I just read his post that is pretty amazing. Going by that, the advantage of supersetting is that it is a tool that should be thrown in at different times to keep the body guessing and adapting from what I understand.