Yes you need to use good form. If pumping blood into a muscle has any effect on growth, then curling 5lbs for a 1,000 reps will pump in a lot of blood, correct?
Now you say moderate weight. Which is different for everyone, so I'll assume it's 10-15 rep range to failure. Can you honestly tell me that If I use good form with 225 on the bench for 10 good reps, It wont make a difference if I use 315 for 10 good reps?
If your playing the size game you need to add weight to the bar. The best programs are based around the principle of progression. But thats just my opinion. Go ahead and do what a pro does who has 20 years lifting experience, who already has enough size, who pays a mortgage to his drug supplier.
ffs dude, he's saying that, for bodybuilding purposes, you use weights you can easily control for slightly higher reps and ensure you're feeling the muscle. He's not saying to try to build up an insane amount of lactic acid, he's not saying avoid the fast twitch, he's not saying never progress... all he's saying is that you don't use the heaviest weights possible. As you approach the heaviest weight you can use, your form starts to break down and the body behaves differently, doing everything in its power to ensure the weight goes up. This is what you want to avoid -- you want to have total control over the weight and feel the target muscles getting hit.
If you can do 315 on bench for five reps, all out, completely balls to the wall, blood pressure through the roof etc, and progress to 320 lbs in a month, 325 the next month, etc. do you really think that if you stick to 225-275 and get 10 reps smooth, perfect reps, getting a huge pump, you somehow all of a sudden are magically not going to be able to add those same five lbs a month and progress, all the while putting way less strain on your connective tissues?
