If form is so important, why can people have developed and/or big muscles who use terrible form and tons of momentum?
When it comes to developing the body, muscles do not know how much weight you are lifting. They do know tension and creating maximum tension (contracting and squeezing the muscles) is key. This is why people who cheat, use momentum with heavier weight, can build muscle. The resistance provides a great amount of tension regardless of form etc. However, tension can and should be generated without weight, by contracting the working muscles. This provides a greater response in building the body. So the best way to develop the muscle is not to just squeeze very hard and use light weights but to use the appropriate weight (even heavier weight than strict form allows) for the amount of repetitions you are targeting while maximally squeezing/contracting the muscles through the movement, manipulating different parts of the strength/force curve and squeezing at different ranges maximally as well.
“Bad” Form, Cheating, and Momentum in Context
This doesn’t mean I don’t advocate bad form (relative), cheating, or using momentum, because these are very beneficial tools in developing the body in a really great and effective way. In the proper context I believe they can and should be used/maniulated to achieve great results.
I believe when aesthetics (person specific) are the desirable goal and sculpting certain parts of the body are the priority, then attention to form and detail are very imperative, whether you are using strict form, explosive reps, momentum or cheating, as long as you are in control. This will cut the risk of injury occurrence by a great amount.
Sacrificing Form to Lift More Weight in Context
When it comes to weightlifting, sacrificing form to lift more weight should only be done in certain contexts within bodily control to achieve a certain effect. Lift with specific intention and control.
Specific to body development, specificity is key. Unless you are a strictly training to see how much weight you can lift/move in general, do not just move weights using any and every muscle in your body. Moving more weight does not matter one bit when you aren’t using the muscle(s) you want to target in the first place. There are great and many times and places for STRATEGICALLY using cheating/momentum movements to develop the physique. Super strict slow form can even hinder your ability to develop muscle and shape to the physique. While strict form and isolating the muscle is imperative, so too is fast, explosive movements, cheating reps, using momentum reps, etc. Training properly using a multitude of methods (and yes, you can and should be in control when you are using cheat reps and momentum) while in control with the appropriate weight for each exercise is what will produce results and a wild physique.
I cannot emphasize the importance of tension enough, as it is very important to understand. The muscle does not know how much weight is being lifted, but how much tension is being generated. This means squeezing and contracting the muscle, and not just moving the weights from A to B (start to finish).
Take note that when I say “the muscle does not know how much weight is being lifted”, this does not mean that weight is not important and to only use very light weight. That is not the case and will not produce desired results. Weight is very important, and the goal is to progressively lift more weight than previously having been able to. Select the appropriate weight specific to the exercise being performed, the number of repetitions, etc.
Poor form (not being in control) leaves one vulnerable to:
- Injuries, acute and chronic
- Poor unbalanced development
- Strength discrepancies between limbs