People think that there is the perfect training routine out there that if they follow it they will see amazing results with their physique. No doubt there are better programs and movements to perform than others but it is NOT what you do, rather it is HOW you do it.
If you are familiar with me you know that I love old school bodybuilding. Some refer to the 40s, 50s, and 60s as the “Silver Era” of bodybuilding. These people (men and women) used basic movements that built their bodies amazingly. They trained hard, correct, implemented strategic ways of moving to maximize muscle growth and shape. They emphasized ratios, proportions and symmetry to create a visually pleasing aesthetic physique with health and vitality as the central objective.
Tension is king when it comes to sculpting the physique. The muscle does not know how much weight you are lifting but it knows tension and force. There are two ways to create tension: Internally and externally.
Contracting the muscle is how you create internal tension. Flexing the muscles as hard as you can during all parts of the range or at selected parts of the range to maximize different points is how you need to be training. Anyone can move heavy weight without exerting much tension to the correct muscles but it is incredibly hard, but very effective, to flex the desired muscles you are working to develop during the movement. Internal tension should be mastered (posing, flexing, learning the art of muscle control) before utilizing weights.
External tension is from the weights being used. You create tension from using the appropriate weight for the repetition range you are using. The force from the resistance creates tension (more internal tension).
Planes of Motion
Muscle fibers run in all different types of direction and have different lines of pull to effectively stimulate that muscle and its fibers. Take the pectoral muscles for example. Some fibers pull across the body and others pull upward. If you are trying to develop certain parts of the chest but your elbow path is not working those correct fibers via the right line of pull than you will not stimulate those muscles for growth and development.
They experimented and asked questions. They did not wait or ask to see a pub med study with x amount of sources to validate whether this muscle is activated or that muscle etc. They experimented and used their brains with how their bodies responded accordingly.
As I said previously, it is not what they did, but how they did it. They trained by contracting their muscles during the movement, not just swinging weight from point to point b. They moved in the correct plane and paths to effectively target the correct parts of the muscle throughout partial and full ranges of motion and experimented with different movements.