These supersets are meant to make life difficult. It's your job to rise to the challenge! Great results don't come without hard work.
In order to get the added size to your chest and back, make sure you do all the reps! If you need to take a pause, do it. And, make sure you make adjustments to the weights to fit your body type. Don't lift with your ego--it doesn't matter what the guy next to you is doing--focus on doing excellent repetitions. You should be pushing yourself to the max, but make sure your maximum doesn't come at the cost of injury.