6. If you are going heavy you can cheat on form
How often do I baulk at some people's form in the gym. Knees wrapped, plates stacked on the bar, squatting down maybe one or two feet before struggling to stand, man that's a knee injury waiting to happen!
If you load up the bench to do only a few quarter-reps, believe me your shoulders don't appreciate that at all!
These people are not only risking injuries, but they are also cheating themselves of gains.
When you are at the gym next time, checkout the guys that wildly swings around 50kg on the EZ-bar for his biceps workout. Believe me or not, this guy only lifts a fraction of that weight with his biceps. The rest is lifted by the lower back and shoulders. But the worst thing is that his elbows have to bear the full impact of the weight that his arm actually can't lift, which can lead to a bad injury.
If you really want to have an optimal muscle growth, you have to engage as many muscle fibers as possible, which can only be achieved with a good form.
With this I mean:
squatting so that your butt will be just below your knees, benching with a controlled movement ( no bouncing!), and curling while your elbows stay at your side with minimal swinging.
A study conducted by Federal University of Rio Grande do Sul in Brazil showed the importance of a good form while lifting heavy. They took unexperienced men and split them into 3 groups: a control group, a partial range group and a full-range groupe. The 3 groups trained 2 times a week for 10 weeks, using a program that increases weight and decreases reps every two weeks. And guess what, the full-range group's strength was 60% higher. Even though the partial and full-rep group experienced muscle growth, the full-rep group's was 29% higher.
So by doing partial reps, you can literally make half the potential gains while exposing yourself to an unnecessary risk of injury.
Which means that if you are lifting heavy and forcing yourself to get the last repetition done, may be a sign that your form gets a little sloppy.
It's okay if you miss the good form by only 3 cm when you are doing your squat or your barbell bounces only a little off your chest. You should always try to keep a proper form. If you find yourself cheating by the second or third rep already, well you are using way to much weight!
Here is what I recommend you:
leave your ego at home and stop trying to lift with your ego! You only harm yourself and you look stupid! People who know what they are doing recognize good form when they see it and they respect it, regardless of the weight that you lift.