I do 12 sets for my Bicep and the same for tricep and both are growing nicely. That tight feeling is the pump, yes. Sometimes I don't get it much and other times I feel like my arm is going to burst. It's caused by blood rushing to your muscles I've always been led to beleive... How much energy you have depends on what you eat as well mate. If I don't eat properly I am like a slob as soon as I enter the gym.

Drink lots of water, and get some carbs in you before you train. If you are half way through the workout and feel slow, your gym may sell like energy boosters. Down one of those I guess. However, eat correctly and you won't need them.

Benni.