In addition to owning my gym, I also belong to 2 others. When I go I often see members doing their exercises with crazy out of control form. When you do an exercise there should be a slow portion and a hold and a squeeze and an even slower section when you let the weight go down as you prepare for the next repetition. If you go too fast you are definitely not going to be working the muscle effectively at all. Your muscle needs a specific message and the slower you go the more your muscle will have to work and recruit more muscle fibers to do the work, which in turn will make the muscle grow and respond faster. When you let the weight down, that is STILL part of the exercise and a very valuable part, and if you let the weight down slowly taking 3-4 seconds to lower is the best so that way you are working optimally on the up(positive) and the down(negative) phase. If you do your exercises in this manner I can guarantee you will see results much faster. Don't be in a rush to finish and get out of the gym. You only really need an hour doing weights if done correctly  --  Mark Gontar