Structure and Frame

The ideal structure for a competitive bodybuilder is what’s called the “X-frame.” This means a bone structure with wide shoulders, narrow hips, bigger legs and a great V-taper. Bodybuilding greats like Ronnie Coleman, Mustafa Mohammad, Jay Cutler, Gustavo Badell, Victor Martinez and Dennis James, all have extremely wide shoulders. And while none will be accused of having small hips, they all have huge thighs and lats to balance the symmetry of their “X.”Bodybuilders from the past whose bodies exemplified the X-frame include Arnold, Sergio Oliva, Lee Haney, Bill Pearl, Steve Reeves, Reg Park and Serge Nubret.

Muslcle Shape

Despite what some magazine articles may claim, you can’t really change a muscle’s shape. Muscle shape is primarily genetic. Therefore, the best physiques tend to have muscles that already possess the right shape, and training simply enlarges the muscle. The best shapes are high, peaked biceps; long, full thighs; small, tight ab dominals; low attaching and wide back muscles (primarily the lats); full shoulders with all three heads clearly developed and visible; full, diamond-shaped calves; and horseshoe-shaped triceps.

Joint Size

Although bigger joints tend to mean more potential muscle mass, nothing looks as good as large muscles on small to medium-sized joints. Great examples of this include Serge Nubret, Flex Wheeler and Dexter Jackson. 

Muscle Size and Mass

While hardness and structure are relevant, bodybuilding is about muscles – strong, massive, powerful muscles! Granted, size is often related to height and bone structure, but few pro bodybuilders or top amateurs weigh less than 200 pounds in contest shape. Nearly every top bodybuilder has greater than 20-inch arms, 50-inch chest, 20-inch calves and 28-inch thighs. Competitors who possess this size in addition to an ultra-shredded look will usually place at or near the top.

Symmetry, Balance and Proportion

It’s not enough to just have huge muscles; the muscle mass must be evenly spread over the body. From top to bottom and side to side, your body must be evenly balanced and proportioned. Your calves should not be noticeably larger or smaller than your neck or arms; your chest should not dwarf your back; your upper body should not make your legs look like stilts. Your ultimate goal is to have your body resemble a Greek statue. If you want to see what ideal proportion looks like, take a look at Dexter Jackson.

Long Muscle Bellies and Full Muscle Insertions

As with joint size and muscle shape, these features are primarily dependent on your genetics. If you watch a bodybuilding contest or look at pictures, you’ll notice that some competitors have muscles that run the full length of their bones, while others have noticeable gaps between the joint and the muscle belly. The biceps and triceps show great variation in this respect, and “high” lats and calves are not as coveted as “low” versions – in other words, it’s preferable to have calves and lats with low insertions.

Muscular Definition

There was a time when the bodybuilder with the largest muscles would probably win any given contest, but not anymore. Today, bodybuilders are expected to carry as little body fat as possible. If your muscles don’t display striations and cross-striations, you can kiss the winner’s trophy goodbye! While genetics do play a role in achieving that “ripped” look, the primary variables for developing muscular definition are diet and cardio.

Vascularity

Vascularity refers to how well the veins stand out in bas-relief on your body. On some bodybuilders the veins will be closer to the surface, while on others they will be deeper. Vascularity is also related to body fat – the less fat on the body, the more the veins will stand out. Some bodybuilders have great vascularity year round, while others’ veins won’t start showing until the weeks leading up to a contest. 

Muscle Separation

As the term suggests, muscle separation refers to how well muscles are clearly separated from one another. It also refers to how clear the sub units of the muscles stand out from one another. For example, on some bodybuilders you can see the dividing line between both biceps heads. Having all four quadriceps heads separated is a must these days. The two pectoral (chest) muscles should be separated by a clear line, straight up the middle. To be really competitive, your muscles should not appear as one large lump of mass. Muscle separation is one of those areas where smaller bodybuilders can hold their own, and often beat larger opponents.

Muscle Density

You can tell the bodybuilders who blow their muscles up quickly with drugs and lift light weight for high-rep sets. They don’t have that powerful, rugged look about them. Instead, they appear almost artifical. Only years of heavy training will give muscles that “dense” look.

High Energy Levels

Building a good-looking physique takes at least a few months. A great one will require an investment of years of high-intensity workouts. Only those with the stamina and energy to endure such physical exertion will survive. A typical champion bodybuilder will train very hard, one to two hours a day, four to six days a week. When you add in the four to six cardio sessions, you can see why this training is not for the lazy!

Natural Strength

With one or two possible exceptions, all today’s top bodybuilding stars are immensely strong. Guys like Jay Cutler, Ronnie Coleman, Mat DuVal and Mustafa Mohammad can each bench press over 400 pounds, squat over 500 pounds and barbell curl in excess of 200 pounds. If you find yourself holding your own with the strongest guys in your gym after a few months of training, you probably have the strength needed to build a large, muscular physique. Training will make you stronger, but those possessing natural strength from day one will usually progress the farthest in the sport.

A Quick Metabolism 

One of the absolute musts of bodybuilding. A great-looking physique means being able to eat a lot of nutritious food and have the calories turned into muscle tissue, not fat. Some bodybuilders can eat in excess of 5,000 calories per day and still keep a six-pack set of abdominals. Others will get fat on 2,000 calories.

High Pain Threshold

Weight training, especially the type required to build a large, muscular physique, is painful at times. Most, if not all, your sets should be carried through the pain barrier. Most of the top bodybuilding stars block the pain out (a few masochists actually enjoy it!) If stubbing your toe or pulling a band-aid off your skin hurts, forget about building a large, muscular physique! You won’t survive the first training session!

Willpower

Are you willing to make sacrifices to build a championship physique? Do you consistently find excuses to skip workouts? Would you prefer to hit the fast-food joint rather than broil some skinless chicken? Do you regularly get 8 to 10 hours of sleep every night? With one or two exceptions, virtually all the top bodybuilders make bodybuilding a top priority. They are not lazy and they are extremely dedicated. This is how you absolutely must be if you want to reach the top.

Positive Mental Attitude

After Ronnie Coleman placed ninth at the 1997 Mr. Olympia, he didn’t settle for merely cracking the top 10. Instead, he banished all negative thinking and set a new goal: to win the 1998 title. Then to show it was no fluke, he won the next seven! Likewise, Jay Cutler didn’t give up after placing second to Ronnie Coleman on four different occasions. 

Determined to finally win the No. 1 spot, he found the positive energy needed to improve his physique and won the title in 2006 and 2007. If your goal is to someday win a major bodybuilding title, then you can’t take a half-hearted approach and be defeated easily. There will be days when going to the gym is the last thing you want to do. But with the exception of when you are overtraining (more on this later in the book), you must kick yourself in the ass and hit the iron!

Source:
Robert Kennedy: Encyclopedia of Bodybuilding, The Complete A-Z Book On Muscle Building. 2008
Nick Evans: Bodybuilding Anatomy. 2012
Arnold Schwarzenegger: The New Encyclopedia of Modern Bodybuilding, 2013