When it comes to building strength, there are 2 huge, controllable factors that determine strength. They are, in order of importance, neuromuscular coordination and muscle size. Neuromuscular coordination is the ability of your brain, nerves, and muscles to work together efficiently to produce a movement pattern. In everyday language we might refer to this as one’s technique or skill. The second key part is muscle size, otherwise known as the cross sectional area of the muscle. Think of muscles as the engine in a car; muscles are what makes the body go. Neuromuscular coordination is like the driver of the car.
While the bench press can benefit from a solid leg drive, the majority of the movement is produced by the muscles in the upper body. Because there is some confusion as to what role certain muscles have in the bench press, I have listed all of the major muscles in the upper body and listed their relative contribution to the bench press. A score of 5 means the muscle is the agonist or the prime mover. A 4 means the muscle is a strong synergist, it will produce actual movement and it will respond to the exercise. A 3 is a weak synergist or a strong stabilizer. The muscle will contribute a little bit to the exercise and it might show some development from the exercise. A 2 means the muscle is a stabilizer during the exercise. It is contracting during the exercise but it is not producing active movement and it will usually not respond to the exercise. However if this muscle is injured it can significantly limit the weight lifted. A score of 1 means the muscle is relatively inactive during the exercise
|Core (Abs, Obliques)||1.5|
Note: It is possible that individual variation, biomechanics, and form might make a muscle work either a little bit more or a little bit less involved based on how the lift is perform.
If you believe that increasing the size of your muscles will help improve the bench, then focus on training the muscles that received a 3 or more on the above scale. Give it 3, 6, even 12 months of hard training. Track your progress and try to establish your own personal correlation between your muscle size and your performance on the platform. It is worth noting that because the bench press requires force to cross the least stable major joint in powerlifting (the shoulder) as you add size to your upper body you increase the stability of the joint, allowing for a much higher level of force production. This is why this lift is the typically the most affected by any change in bodyweight.