Bodybuilding exercises should take a muscle through its longest possible range of motion, with some exceptions. You should take care to stretch out to full extension, and then come all the way back to a position of complete contraction. This is the only way to stimulate the entire muscle and every muscle fibre. Whether you are doing 8, 10, or 12 reps for example, it is assumed that you are completing each rep to its full range of motion.
Quality Contraction For Muscle
Bodybuilding is all about training muscles, not lifting weights. You must use the weights and proper technique in order to target certain muscles of muscle groups. Weights are just a means to an end. In order to train effectively, you have to isolate the muscles you are targeting. When out of the gym and you are lifting something with your legs, and not your back, this technique deliberately brings as many muscles into play as possible to protect you from injury. In the gym, however, you don’t want to make the lift easier, in fact you want to target muscles to do all the work, with little or no help from other muscle groups.
Use the Right Weight & Technique
When you use a weight that’s too heavy for your target muscles, your body automatically calls other muscles into play. Your nervous system has been designed with this in mind. The mere fact that you can lift a weight, does not mean that you can do the exercise correctly. You also need to choose a weight that ensures that you target the intended muscles for lifting the weight.
Feel the Muscle Working
Start lifting with light weights and concentrate on how the muscles feel throughout the movement. Once you are satisfied with this weight, gradually increase it. When you get to a point where you can no longer feel the muscles working as they did when the weight was lighter, chances are you are working too heavy and need to back down a few kilos to re-establish this ‘feel.’
Maintain Form For Muscle
When training for bodybuilding, it is important not to compromise form, to ensure that you recruit the maximum amount of muscle fibre throughout a movement. Initially it may feel like you are using too light a weight, but it is better to gradually increase the kgse, without sacrificing form. Some exceptions do exist however, such as using ‘partial reps’ for training.