Genomics

[diesel23]

Little Jay, there are MANY factors which will affect the activities you are inclined to excel at and strength levels.

ONE of them is limb length. Short levers HAVE an advantage over longer levers.

But that is ONLY ONE.

Another predispositioning factor is - you guessed it - the number of muscle fibers you were born with in a specific muscle. If you were born with less muscle fibers, then you have a disadvantage in terms of strength, power, endurance.

Another predispositioning factors are the predominance of muscle fiber type. Fast twitch muscles will get stronger and bigger more easily than a slow twitch muscle.

Another predispositioning factor is how how fast is your metabolism.

Another predispositioning factor is hormone levels - Growth Hormone, Testosterone, IGFs, Insulin, estrogen. Also poor insulin sensitivity will hurt you in terms of progress.

Also, what type of diet you’re naturally inclined to be on. We all descend from different cultures who adapted to slightly different diets and environments. You wouldnt expect an igloo man whose ancestors all lived in icy conditions with little carbs to do well on a high carb diet filled with donuts and oreos would you?

Another factor is mental attitude. Someone who quits easily at the first sign of pain is bound to make less progress.

Another factor is your body’s ability to use a specific energy system. These can be anaerobic (ATP+CP, Glycogen) and aerobic (glycogen). If you’re not effective at using ATP+CP, or if your body naturally stores little of these, you’re less likely to excel at power/maximal strength activities.

Muscle cross-sectional area cannot be overlooked as factor either. Someone with a large cross-sectional area will have greater strength potential than someone with tig arms - and this factor can affect your performance more than limb length. Muscle CSA is affected both by number of muscle fibers as well as hypertrophy of each muscle fiber.

Also, what accounts for muscle size? If you have great numbers of cappilaries and sarcoplasmic volume in the muscle, your strength is likely to be poorer in comparison to the muscle’s CSA.

There are SO many factors.

Limb length is but ONE of them. You can have bad luck at one factor, but have the jackpot in all others - and go on to excel at a specific sport.
BUT limb length still affects you, and all things being equal between two competitors, the one with shorter limbs will be able to DISPLAY greater maximal strength, but they both will be able to apply the same ammount of torque - and in a sport like baseball, torque is the name of the game.

In other words, if you’re short and you’re still eak, then you havent worked out long enough to bring out your potential, or you have a number of other factors playing against you. It doesnt matter how short your arms are, if you have but ONE muscle fiber connecting the humerus to the forearm, you wont flexing much.

[andersons]

Da Man, I agree with some of what you say about genetic limitations. No amount of training, nutrition, supplements, or drugs will magically put muscle fibers where there’s currently only tendons/ligaments. True. But how MUCH hypertrophy you can achieve in the muscle you DO have is unknown. People continue to raise the bar of achievement to higher and higher levels. No one knows whether there is a true upper bound (asymptote) or not.

There are a whole bunch of known factors that influence muscle mass. Controlled studies that try to measure the effect of each factor generally can attribute only 10-30% to the genetic factor. (These are not studies of muscle mass, but of a host of other observed conditions, all finding similar ranges of influence of genetics.) Even that 10-30%attribution is hard to separate from experience, because the expression of genes can depend upon environmental factors, right from conception.

One researcher found “Even physiological and anatomical attributes can change dramatically in response to physical training. [But we knew that, that’s why we’re training, right?] As the amount and intensity of physical training is increased and maintained for long periods, far-reaching adaptations of the body result. . .a surprisingly large number of anatomical characteristics show specific changes and adaptations to the specific nature of extended intense training. . .” (Ericsson, Krampe, & Tesch-Romer, “The Role of Deliberate Practice in the Acquisition of Expert Performance,” Psychological Review Vol 100 No 3).

So the evidence suggests that the amount of time you spend training your calves has a greater effect on them than your genetics does. If there IS a genetic upper bound, it hasn’t been found. There are diminishing returns, but no study has found a true asymptote.