I have to admit that pumpster has a point.
To many people tend to do to many sets when they're lifting weights. Small warmin-up, 2 tot 3 sets, and then your heaviest.
It doesn't kill, it doesn't hurt you, but it does put a high amount of stresslevels to everything.
imo this method is best to break a certain plateau. If your stuck for a certain amount of time with a certain weight,
stop wasting energy with endless sets of pressing, and go immediately heavy. You will found out that you can lift more.
But it's wise to use this kind of technique only with a decent spotter.