There remains a common belief that the shape of a muscle can be altered by performing specific exercises. It is also believed by many that the number of fibers in a muscle can be increased. Neither of these premises are correct and are examples of muscle shaping mythology.
You cannot increase or decrease the number of fibers in a muscle, additionally the shape of your muscles is determined by genetics and cannot be altered by exercise.
Some individuals have long muscles with short tendons (the fascia that attaches muscle to bone), whilst others have short muscles and long tendons. Unfortunately, unless you opt to have surgery, you cannot change the shape of the muscles you were born with (i.e., increase a “peak” in a muscle or make a short muscle long). You may, however, change the size of muscle fibers and thus change the shape of the muscle overall (i.e make a muscle bigger or fuller). Muscles can only hypertrophy (get larger overall) or atrophy (get smaller overall).
The myth that you can, by exercise, change the shape and length of your muscles however continues to be widely believed among many of the physical culture fraternity.
The length of the muscle belly and the length of the tendon can differ for every individual, but the insertion of the muscle is virtually the same in everyone, differing only by a few millimeters.
Looking at the calves as an example: If someone’s calves have a “high insertion” then what they actually have is a very short muscle belly and a long tendon. If they have a “low insertion” then what they have is a long muscle belly and a short tendon. Those individuals with long tendons will have what is termed” high calves” which tend to be resistant to hypertrophy and difficult to develop. Conversely, those lucky enough to have short tendons will have low calves which will naturally look full and well developed, and will likely be more responsive to resistance training.
Examples of muscle shaping mythology
There is an old training myth that “high calves” can be lowered by stretching them on a block and performing calf raises through an extended range of motion.
Additionally, perfect diamond shape calves cannot “be created” because, regardless of exercise, you retain the shape that you were born with, you can only increase their size. A similar myth exists that lying pullovers develop the rib cage and increase thoracic expansion, but after the age of around twenty one years this is extremely unlikely.
Former Mr Olympia Franco Columbo displayed a strange split in his chest musculature between upper and lower pectorals. This was attributed by some as the effect of isolating the upper pecs by doing incline bench work, when in reality the anomaly was purely a genetic trait. Similarly, contrary to training mythology there exists no abdominal exercise that corrects asymmetrical abdominals, or even lack of prominent abs (which is rare). Boyer Coe a bodybuilder from the 1970’s, was famous for his beautifully peaked and split biceps, but he lacked evidence of abdominal development even with low levels of bodyfat.
Unfortunately you can only develop what nature has given you. If you are genetically gifted with a symmetrical six or even an eight pack, long clavicles, narrow hips and long muscle bellies like for example Flex Wheeler had, you are lucky and could potentially obtain a very aesthetically pleasing physique. Structurally of course if you have inherited narrow shoulders and wide hips you can do nothing to change this, anymore than you can change the relative length of your limbs. You can only try to create an illusion to negate the effect .
Larry Scott possessed narrow shoulders but developed cannonball size deltoids to make them look wider and compensate to improve this genetic deficit. Larry was also a keen exponent of the preacher curl which even got renamed the “Scott curl” after him. This exercise along with concentration curls was falsely touted by some as being able to develop the lower bicep and increase bicep peak, neither of which it could do.
Other trainers have claimed that developing the brachialis will increase the bicep peak effect, as will doing curls to emphasise the various heads of the bicep. The biceps peak however cannot be effectively developed as the shape of all muscles is genetically determined and unalterable.
This myth is still circulating regularly on bodybuilding forums and in magazines, stimulating endless debates among misguided trainees and older trainers who should know better. I am baffled that despite the fact that no bodybuilder in history has ever significantly changed the shape of their bicep this myth persists. If a peak could be obtained by doing a certain exercise, in a certain way, we would have endless bodybuilders with peaked biceps and elite level Olympian bodybuilders like Dennis Wolf would not possess long flat biceps without any peak.
I remember that David Dupree a golden era bodybuilder competing in the 1970’s was gifted with peaked biceps which had a beautifully pronounced split. He tried various exercises in order to “smooth out” the split! His hero was Steve Reeves whose biceps did not display a prominent split. At the same time trainees were performing various curls to “isolate the long head of the biceps” desperately trying to obtain split biceps and increase its peak. Sadly, of course all their efforts were in vain.