T Nation

The Truth About Genetic Limitations


From "The Thinker" On EliteFTS.

The reason lies in the function of the type I, IIA, and IIB fibers.

It is for these reasons why there are many effective methods used by bodybuilders as well as powerlifters; however, not so many used by weightlifters, throwers, sprinters, etcetera and perhaps this is most significantly a result of the importance of genetics.

The fastest and most explosive athletes are largely genetically predisposed to excel in such disciplines due to their inherited larger percentage of white fiber, favorable anthropometry, tendon lengths, and so on and the room to advance these capacities is very small to non-existent;

While the goal of becoming only maximally strong or muscle bound is only marginally dependent upon genetic material and nearly anyone, regardless of inherited gifts, can become very muscle bound and strong in the limit sense via proper training and nutrition.

It is for this reason why you will witness a plethora of bodybuilders and powerlifters speak of how they were skinny and/or weak early in life and through years of training and nutrition they reached very high status.

You will not, however, witness elite caliber sprinters, for example, speak of how slow or nonexplosive they were early in life because, for all intents and purposes, you either have it or you don't.

In closing:

The more dependent the sport result is upon the anaerobic alactic function of the white fiber- the more the athlete's success depends upon inherited genetic material.


'White fiber',dude that's just racist.


How does this not apply to powerlifters?


I could be wrong on this but I believe it goes something like this...

Type I Fibers are Red, Slow Twitch Fibers. This is the endurance stuff.

Type IIa Fibers are Red, Fast Twitch Fibers. This is the fiber type that you can make nice and big.

Type IIb Fibers are White, Fast Twitch Fibers. It sounds like the thinker is saying there's not a lot of room for improvement with this fiber type.

Type IIa Red Fibers are very trainable. Between training these fibers through lifting in the 5-15RM range and training the CNS through lifting in the 1-5RM range you can get big and strong.

So if genetic limitations are mainly on white fibers, then healthy individuals are capable of gaining considerable amounts of muscle mass by training Type IIa Red fibers.

An Aspiring Powerlifter whose genetics have left him with less-than-world-class Type IIb fibers will need to accept the fact that he will not be able to get an elite total at his current bodyweight of 165 and height of 5'9".

So between training his Type IIa Red Fibers and his CNS with heavy weights, he can still reach his lifelong goal of an elite total by putting on enough muscle to walk around at 250lbs and compete at 242.

Maybe I'm wrong. But if I'm wrong then I just don't get the whole picture. It's not because what the thinker says is wrong.

Maybe I'm biased - but the argument that type IIb fibers aren't very trainable just makes a lot of sense.

I attempted to throw Javlin last spring and I was TERRIBLE. Despite the fact that I was nearly twice as strong as everyone else throwing Javlin my distances sucked huge donkey balls.

(Although this had a lot to do with my novice level technique, much weaker kids with technique about as bad as mine could still throw farther than me.)

I can out Power-Clean everyone I knew in High-School who can Dunk, but I'm not even close to being able to Dunk.

Well, then how is it that the Olympic Lifts and Dynamic Effort Power Lifts can be done so fast with such heavy weights by the big, strong guys? I'm assuming that explosively Benching 275 has a LOT more to do with Maximal Strength, Type IIa Red Fibers, and CNS efficiency than it does Type IIb fibers.



I wonder if you could test it.

Something like throwing a baseball as far as possible 10 times and then averaging the distance.


Very interesting. Thanks FightingScott.

The wrench in the works are those people who do not look athletic (or genetically gifted) at all and still break records or are in the hall of fame. Babe Ruth? Now I know that being genetically gifted for something goes further than just muscle type.

Also location, frame, etc will play a role. Shoot, in Babe's case maybe hand/eye cordination or the type of muscle fiber in the forearms causing explosiveness off of the bat and that was his genetic blessing. Or the ability for his liver to rid the body of a lot of alcohol..idk...lol

I think a point to be made from Babe (or your analogy/person of choice) is that genetics play a huge role in something but there can be exceptions. Genetics is something we cannot control without the use of PEDs so don't fuss about it too much, if your good at something stick with it...

I know several people who are good at their hobbies that may not have the best genetics for that particular hobby. Another point that could be made is that people tend to pick the hobbies that they are genetically good at.

My view on things is that if your heart is into something then your head will be too. If you can put your heart/mind together anything can be accomplised imo. Now the thing is, you cannot force the heart into something, that has to come naturally.

When it does embrace it because that doesn't not happen very often. Many times we put our heads into something and think our hearts our in it but they aren't. If your heart is into something you could do it 24/7 and be happy. Anybody see my point there?

Wow I made a lot of 'points' in there but re-reading it sounds like jarble...oh well, interesting read man thanks for that. Hopefully my 'points' get across to somebody. LOL



I read a quote today, maybe here but not sure. Possibly a video...anyways:

"the only way to find one's limit is to push past it"

I believe there is truth to that. How do we really know where a limit to something is unless we are trying to push past it. If you stop and say I'm done and cannot improve anymore you might as well call it quits. We do not know for certain that is the limit, but you are giving in and accepting.

My high school baseball coach told me this before playing college ball and it is probably the singlemost motivation for my life with anything I chose to pursue.

One of my life motto's:

"When your through improving, your through"

Man I'm postwhoring like a mutha tonite! lol



The main point of me making this thread was to suggest that the impact of genetics is relativly limited.

The list of things that genetics mostly controls (like height, bone structure, and white fiber distribution) is a short list. Since the list of limitations that are truly genetic in nature is short, the list of doors that have been closed off to you is pretty short as well.

What's the worst if you have bad athletic genetics but you're healthy? At worst you just don't possess the short list of athletic qualities that aren't very trainable.

How many doors does that shut for you? How many are left open? So what if you can't do the events you suck at in track?

There are plenty of highly trainable athletic traits, such as Maximal Strength, Endurance, and Psychological Strength that can be raised to a very high degree - high enough to outweigh the detriment your weaknesses cause. And raising these highly trainable traits should open a lot of doors for you.


This post was flagged by the community and is temporarily hidden.


That still leaves enough highly trainable qualities that are of importance in athletics.

And whether you agree with the ethics of it or not, you can manipulate your hormone levels but you can't manipulate your fiber distribution.

You also might be able to find people who got the short stick on one or two of these traits, but I think it's pretty rare to find someone who is healthy, yet his or her genetics truly suck in every way possible.


There is one very interesting study showing a massive increase in type IIb fibers by taking long off-training periods.


This post was flagged by the community and is temporarily hidden.


This post was flagged by the community and is temporarily hidden.


For some reason I can't see it catching on...


What he wrote is totally false. Muscular potential is not much less dependent on genetics than any other facet of physical ability. The source of the misconception is probably the fact that few people ever approach their bodybuilding potential, so people who train can exceed the physiques of more gifted people who don't train. Neverthless, if everyone trained, it would become immediately obvious that genetics is THE most important factor influencing physique.


I agree with this. The problem pops up when people who don't try that hard blame their lack of results on their genetics. Most people on the planet should be able to drastically change how they look. The ones who can do this as well as stand out amongst the elite are much fewer than the general population.

If you can't build arms over 15", chances are, the problem is NOT your genetics but your lack of effort in the gym and the kitchen.

If you can't build arms over 19", that may be the result of your own genetics.


prox whats your opionon on genetics when u reach a preety high level of bodybuilding, either ifbb or npc. How far do you think someone could make it would average genetics?


Haha, that's some hardcore dedication right there :smiley:
Funny though, because I thought about it once that if you went everywhere in a wheelchair but still did sprint training you would get massively explosive because of you only needing to adapt to that. I would really like if you could get your hand on that study, just to see if I finally had a smart thought :stuck_out_tongue:


I still can't touch the freakin' rim on the goal yet. My friend who dosen't train can hang on it like a monkey. The same guy closed my COC gripper on the first try. Ive been struggeling with it for over a week now and still can't close it. He said he set records in high school track though so Im sure he has gifted genetics. Its actually more annoying than anything.


Truly "average" genetics would find most people unable to get arms larger than 18" in my experience. So obviously, there won't be many "average" people at the truly higher levels of competition if we are discussing heavy weights. There are TONS of people who compete in NPC contests as light heavies and lightweights who aren't carrying as much size but still look amazing.

A ripped to shreds 18" arm means the guy is walking around with arms over 19" the rest of the year at least. You need to understand things like that when discussing competitors in contest shape. the average guy is walking around AT LEAST 20-30lbs heavier in the off season with most over 50lbs heavier. That is why if you have a goal of weighing 190lbs ripped, you had better be over 220-230lbs in the off season.