In my last article, I laid out what I consider to be five of the best strategies for building the ultimate male physique, which really is a discussion about developing a body that others consider “sexy,” for lack of a better word. It's a really interesting idea: building a sexy body. We all know what makes for one, but we don't always think about why those characteristics are associated with sexiness.

For example, why do women want men to have broad shoulders? The answers to those questions are grounded in hard science. We view certain physical traits as desirable in members of each sex. An X-shaped physique for men implies virility and strength, just as an hourglass body on a woman suggests fertility. We view what is attractive partially through the eyes of people looking for mates because of scientifically proven numbers.

**Sex Appeal: It's In The Numbers**

Believe it or not, our definition of what’s attractive is only partially a matter of “taste” and is more a matter of math. Put another way, the immediate internal decision about whether we’re attracted to something or someone is, in large part, a highly mathematical process. That process, like all math, is based on certain formulas – in this case, something we call the golden ratio.

This is a number that shows up all over the human body (for example, the length of the arms and legs, compared to the torso), and it seems to define what proportions look best.

In fact, artists and sculptors have known about the golden ratio for a long time and have used it to create sculptures and artwork of the ideal human figure. To this day, surgeons and dentists use it to restructure the human face.

**The Golden Ration Defined**

OK, so what is the golden ratio, exactly? It is, in mathematical terms, a comparison of any two aspects that leads us to proportion them in the ideal way. Algebraically, if you have two numbers, A and B, it has to be such that (A + B) divided by A = A divided by B.

In most cases, this is going to be a comparison result in a ratio of 1:1.618. This appears naturally all over your body. For example, if the length of the hand has the value of 1, then the combined length of hand and forearm has the approximate value of 1.618. Similarly, the proportion of upper arm to hand + forearm is in the same ratio of 1:618.

Measure your lower body and you’ll find the same: If the foot is 1, then the length of the foot + the shin is 1.618.

Looking elsewhere on the body, the face is another great example. In fact, the human face abounds with examples of the golden ratio. The head forms a golden rectangle with the eyes at its midpoint.The mouth and nose are each placed at golden sections of the distance between the eyes and the bottom of the chin.

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Now, while all of that is interesting in terms of physiology, what is far more interesting, I think, is the effect is has on psychology. You see, our brains are programmed to look for symmetry and balance everywhere; programmed to be attracted to it and to try to create it. This means that what we consider a good body is really based on what we view as a body that projects certain characteristics and bodily symmetry, and that symmetry is determined by the golden ratio.

**The Golden Ratio**

So, the more a body fits into the parameters laid out by the golden ratio, the more attractive it will be, both physiologically and psychologically. It's a really interesting bit of science and evolutionary psychology, and it begs the question: How do we use this information to help you achieve your fitness goals and get the body that you want?

Well, the first thing is to realize that, chances are, the body you are working so hard for is based on our intrinsic ideas of symmetry. Of course, the numbers are just everywhere in places we can't control. Thankfully, not many women are going to be looking closely enough at your feet and shins to make sure they add up correctly.

That said, the golden ratio also applies heavily in places we can control, and the most important one by far is the most visible: your waist-to-shoulder measurement. As mentioned earlier, broad shoulders imply strength, power and virility, and are, therefore, a mating qualifier that makes a body appear more attractive to the opposite sex. But “broad” is a relative term. Something can only be “broad” if it’s compared to something less so, which is where your shoulder-to-waist measurement (and the golden ratio) come in.

**The Adonis Index: How Do You Measure Up**

If you want to build a body that is attractive in any type of wardrobe and is noticeable even from across the room, you need to optimize your Adonis Index. You need to develop your shoulders so they’re broad compared to your waist. The perfect dimensions are – you guessed it – in line with the golden ratio. So, if your waist is given a value of 1, your shoulders should be 1.618. This would be considered the “ideal” Adonis Index.

Now, let’s say you’re a skinny guy looking to gain some muscle. If your waist measures 28 inches, then your goal for your shoulders should be just about 45.3 inches. Even if you don’t immediately gain a tremendous amount of muscle, as long as you develop your shoulders to fit that proportion, you’re on your way to a “perfect” body.

Alternatively, let’s say you’re on the bigger side and you want to drop some weight. Maybe your shoulders measure 54 inches around – quite a big guy, and certainly powerful looking – but your waist could use some help. In this case, all you need to do is drop enough weight to bring your waist measurement down to around 33.5, and your proportions will be immediately more attractive. That means, you don’t need to get “super lean” just to improve your body and improve your Adonis Index.

**A Case Study**

Let’s work it the other way and put the Index in perspective. Let’s say we have a guy with a 34-inch waist whose shoulders measure 45 inches around. His current Adonis Index is about 1.323; he has some work to do.

If he diets down a bit and brings his waist measurement down to 32, his measurement will jump to 1.406. That means without increasing his muscle mass at all, a mere two-inch reduction in his waist has brought him a lot closer to an ideal Adonis Index and an improved body.

If this client wants to take it a step further, he can adjust his training workout to add size to his shoulders. If he can add three inches on the total circumference, he’s pretty much set. At 48 inches with a 32 waist, our client is now at an Index 1.5, which is amazingly close.

**Put It In Action**

Here's a question I want you to ask yourself: If you've been trying to get a "perfect body" and you’ve been having some success despite taking wild stabs at what that means, think about what this means for you. It means that now you can select your workouts based on your specific needs.

If you're trying to build an impressive body – with strong, broad shoulders and a narrow waist – you definitely want to pay careful attention to the golden ratio and to your Adonis Index. The perfect body may be closer than you think.

**Next Steps:**

1. Determine your goal: fat loss or muscle building?

2. If it's fat loss, measure your shoulders. If muscle building, measure your waist.

3. If you’re trying to lose fat, focus on getting your waist measurement to fit the Adonis Index, as determined by your shoulder measurement. If you’re trying to gain muscle, focus on developing your shoulders to be 1.618 times your waist measurement.