Genetics and body proportions
Bodybuilding Genetics
You inherited your genes from your parents and grandparents and this determents for up to 80% on how you look. The other 20% are determent by environment , life style and personal choices. If your parents were very tall, you are probably are very tall too. If you want to become a basketball player than you can consider yourself lucky.
Is length favorable for bodybuilding? Fact is that most pro-bodybuilders are rather small. A smaller guy looks blockier much quicker. And most tall bodybuilders have trouble putting on muscle on their legs. But we all know the exceptions. One of them is Lou Ferrigno.
Comparison of two bodybuilders: Flavio Baccianini height 147 cm (4'10") vs Lou Ferrigno height 196 cm( 6' 5"). Flavio weighing 66 kg and Lou 136 kg. Baccianini placed 13th in the 1993 Mr. Olympia which placed him just three spots down from Lou Ferrigno that year.
Several aspects of a person’s physique reveal genetic potential.
First of all, there’s your basic skeletal structure. The ideal frame for bodybuilding is wide shoulders with a narrow waist and hips. That look is exemplified by bodybuilding champions such as Steve Reeves and Lee Haney. They both inherited a superior bone structure that was exaggerated even more when they developed their physiques.
Your skeletal structure is completely genetic because there’s no exercise you can do to widen your shoulders or narrow your hips. You can, however, emphasize certain areas of your physique to help overcome those structural deficiencies. Bodybuilders like Larry Scott and Rich Gaspari worked hard on developing bigger medial deltoids so they would look wider in the shoulders and narrower in the waist. Rich also cut back on heavy squats because they were making the muscles in his waist bigger and making him look more blocky.
Another genetic predisposition is your ability to add muscle size. Some people are naturally more muscular and bigger. They’re the mesomorphs, and they grow much more readily than the average person. It’s a function of the number and type of muscle fibers a person is born with. “Stubborn calves” are an extremely common bodybuilding problem. But bodybuilders found ways to overcome their genetic limitations. I’ll cover that later in this blog-post.
Bodybuilders like Casey Viator, Eddie Robinson and Jay Cutler are pure mesomorphs, and they developed massive size soon after they began training. Interestingly, Casey, Eddie and Jay were all teenage national champions—further evidence that getting big came pretty easily to them. Picture: Just look at the enormous genetic potential this kid has, sadly for him his economic and social outlook are probably more limited.
Another big factor in bodybuilding is your ability to be ripped and fat free. Some individuals have a faster metabolism and can get conditioned much more easily than the average person. That’s very important because being ripped is such a big factor in bodybuilding competitions today.
People who have fast metabolisms may have a more difficult time adding size, but when they eventually do get bigger, they have a huge advantage over their competition because they can get so ripped. Most bodybuilding contests are won by the person who’s the leanest and most conditioned.
If your gym buddies told you that you have good genetics, they may mean that you have a good structure and good shape. If that’s the case, continue working out hard to add more quality size and enhance your natural shape. Work on developing your muscle groups so they’re all in proportion to one another, and make sure you enter the contest in ripped condition.
Physical and Mental
You inherit not only physical but also mental (and health) characteristics. If you were lucky you also inherited willpower, determination and the ability to focus. In bodybuilding the mental attitude toward bodybuilding is very important, mind over muscle remember? The will to go to the gym, the aerobics, the diet, it needs a certain mindset to continue. Lifting changes more than just your body. Lifting can change how you participate in and view the world. It greatly improves your self-esteem, and even the girls will look at you differently.
Your bone structure affects posture, the question is if they are postural habits or an anatomical inheritance. But no matter what, you can force yourself to take the right body posture. Also bodybuilding will help to strengthen the musculature and core.
It’s not all genetically determent, New research has emerged that indicates that although genes may be passed down to our offspring, diet, environment and lifestyle can either turn the gene on or off.
Body proportions
Legs of a 'tall' man?
In tall people, we tend to associate long legs as being almost purely responsible for their extra height. In reality, taller people's height is also due to spine and neck length, though the contribution each of these make up can vary quite wildly between different people. I'm sure everyone's seen at least one movie where the main character offends a guy sat down (usually in a bar) who looks normal, but then stands up to reveal he is substantially taller than the main character to comedy effect. Clearly in this case, the tall person is tall because of having long legs.
Arnold's legs are without a doubt, proportionally long compared to the rest of his body. Exactly how 'long' his legs are depends on how tall Arnold actually is.
Early in his bodybuilding career, Arnold's legs were criticized for being underdeveloped compared to the rest of his body, and he had to work hard to build them up to match the muscles of his chest, arms, etc. Why did Arnold find them harder to build up than his upper body? Well, the answer is that they were too long.
Traditionally bodybuilders are slightly shorter than the average man. It is rare to find any bodybuilders at the highest level of the sport over the 6 foot mark. long spines tend to make for long mid-sections which make the chest and back appear smaller. Long legs leave a larger surface area of the muscle to build up and also make many leg exercises difficult to do, due to the extra range needed to perform those exercises (e.g squats, leg presses).
As we can see from the above photograph, Arnold's legs look very long compared to Reg Park's (right) and Dave Draper's (center) legs. Dave Draper is considered by all accounts to be around the 6 foot mark, and also is known for having very long legs. Reg Park, considered to be 6'1" or 6'2" (depending on the source) appears roughly the same height as Arnold in this photograph, yet his legs are shorter by at least 2 inches. Notice that the region between Arnold's navel and the bottom of his chest is a substantially shorter area than with the other two.
How do bodybuilders manipulate their genetic potential
First you have a big plus when you start young - muscles and bone structure are adaptive to workload.
In the past when you were genetically “blessed” with a big nose, you had to cope with it. Nowadays most girls in the USA are okay to fix their nose or breasts.
The same is true for bodybuilding. Most kids are okay with popping some d-bols. Also young bodybuilders use hormones, peptides, insulin and other chemicals to boost their metabolism or anabolism.
Furthermore all kinds of exotic means are used such as SARMs , interleukines etc.
Just as teenage girls bodybuilders no longer accept the limitations of their genetic gene-pool. This is not exactly new and I posted about here: //juicedmuscle.com/jmblog/content/site-injections-progress-or-madness?page=1
A musclegroup especially notorious as a lacking muscle-group in tall bodybuilders and some African races also Americans with African roots are the calfs. Some are simply unable to make them grow. On the discussionforums you can read how members react on 
the calf implants by example by Lou Ferrigno.
Esiclene is a compound used in bodybuilding for almost 40 years. After Esiclene came Caverject then came Nolotil, PGF2a, Synthol, implants, site-injects etc. Some even deliberately create scar-tissue.
On our forum a lifelong French champion pro-bodybuilder posted: “I win my first championship in my country with esiclen, (but win without the same I was ripped like never ) I put it in calves , biceps and shoulders, only 1 or 2 weeks before contest, all good competitors of my country make the same. Some put in back and chest but it was not good, and for me no problem back and chest (pectoral) was already big and ripped.sometime if you put too much, it was not good, you loss the effect ripped of muscle. I know some professional that take it, and some take yearlong to have progress in calves or another muscle , but I don't know if it was good. Nolotil and another are not the same for me (old school) esiclen like real parabolan are fantastic.”
Doctors struggle with ethical dilemmas. Parents ask them to stunt the growth of tall girls, or ask them to administer rhGH to their boys to enable them to grow tall enough to become successful basketballer.
Growth hormone increases the metabolism, that is, the rate at which the cells of the body consume fuel and nutrients. Some children may become unusually lean, losing body fat and becoming inappropriately muscular (Walker et al 1990).
To summarise, today we are able to look how we want, Conrad et all 2010:
“It is likely that people have sought enhancements for themselves or their children for as long as they have recognised that improvements in individuals are a possibility. These might have included strategies, techniques or potions to make humans stronger, smarter, faster, live longer or with keener senses. In contemporary society parents seek to enhance their children's life chances by providing music lessons, tutoring, private school education, after school programmes, summer camps and the like. Adults may endeavour to enhance themselves with supplements, exercise workouts, special courses, and diverse cultural experiences. There is no shortage of methods of self-improvement, many of which could be called enhancements.
One particular genre of self-improvement in modern society is ‘biomedical enhancements’. These include drugs, surgery and other medical interventions aimed at improving mind, body or performance. Cosmetic surgery, including liposuction, face lifts, breast augmentation and ‘nose jobs’ have become a common biomedical road to bodily improvement. Performance-enhancing drugs, often used by athletes for sporting competitions, such as steroids, hormones and stimulant medications, have caused controversy. More recently, Peter Kramerhas conceptualised certain drugs like Prozac as having the potential qualities of ‘cosmetic psychopharmacology’, making individuals ‘better than well’.
There has been considerable social concern about the potential of genetic engineering as a new and particularly powerful form of biomedical enhancement.”
Myostatin inhibitors ? Naaah 
//juicedmuscle.com/jmblog/content/site-injections-progress-or-madness?page=1