You can train muscles in three ways: eccentrically (lowering the weight), concentrically (lifting the weight), and isometrically (standing still). Isometric training doesn’t have a prominent place in bodybuilding. Is that justified?

RESEARCH

The surprising answer is: no. Isometric training can produce the same growth stimulus as “normal” repetitions with a concentric and isometric portion. This was demonstrated in a recent scientific study in which each participant trained both legs: one leg with isometric contractions in the starting position of the leg extension, the other with regular reps of the leg extension. Both methods resulted in a similar amount of muscle growth.

This is in line with the results of four previous studies.

WHY DOES ISOMETRIC WORK?

As you may know, muscles grow as a result of mechanical tension. This is the amount of tension a muscle must exert when it’s subjected to resistance from dumbbells, barbells, or other heavy weights.

It’s a misconception that the weight must move under mechanical tension. With isometric exercises, the muscle fiber remains continuously activated, which creates a different, and sometimes even more intense, stimulus than with sets of concentric and eccentric training.

It’s all the more striking that isometric training is rarely used in contemporary bodybuilding. Except occasionally for injury rehabilitation (isometric training means low impact on the joints) and for exercises like planks and wall sits.

EXERCISES

Some examples of isometric training:

• (RKC) plank: you keep your body in a straight line, supporting yourself on your forearms and toes;
• wall sit: you sit upright against a wall with your knees bent, as if you were sitting on an invisible chair;
• isometric push-up: you lower yourself slightly and hold that position, instead of performing the entire movement;
• wall push: push against a wall with full force;
• chest squeeze: press your hands together using your chest muscles;
• isometric shrug: the regular shrug but holding the top position for 15-30 seconds;
• bridge: lie down and push your body up so that only your feet and hands are touching the floor. Hold this position for 15-30 seconds.
• superman: lie on your stomach and extend your arms out in front of you. Now lift your legs and upper body. Hold this position for 15-30 seconds.

CONCLUSION 

Muscle growth requires tension, not necessarily movement. This isn’t to say you should replace your regular workout; isometric training is a valuable addition.