This one gets tossed around a lot. Genetics are a favorite scapegoat for people who can’t effectively build muscle or lose fat. But what are they, exactly, and how much do they actually influence your results?

The word genetics comes from a Greek word meaning “origin,” and it refers to the molecular structure and function of our genes.

Genes are molecules in our DNA that provide instructions for the creation of special types of proteins that then tell each of our cells what to do, such as build muscle, make bone, carry nerve signals, and so forth.

While our bodies all contain the same types of genes, our programming is different.

For instance, the cells that form my iris were programmed to be a certain shade of blue, whereas yours were programmed to be a different shade, or a different color altogether. This variability in programming applies to every physiological activity in our bodies.

So yes, your genes determine things like which muscle groups tend to be your “strong points,” your natural hormone levels and rate of muscle growth, and how much fat you tend to hold on your body and where you tend to store it.

BUT…they don’t alter the basic physiological processes by which your body builds muscle or loses fat. So long as you don’t have disease directly impairing these functions, you can get into amazing shape if you know what you’re doing. Period.

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I’ve helped quite a few “hardgainers” over the years gain 30, 40, and even 50 pounds in their first year or two of training and eating correctly (and with no drugs). I’ve helped scores of men and women who were convinced that they were genetically programmed to be fat build lean, muscular physiques by just fixing the many little things they were doing wrong.

So if you’re afraid that your body is genetically destined to be small, weak, or fat, you can lay those fears to rest. Your body contains the same genetic programs as mine that result in muscle growth and fat loss.

In fact, your body might be able to do certain functions relating to these things better than mine. If I’ve made better progress than you with my physique, it’s only because I have a better understanding of how to kick those programs into gear—that is, I know more about proper training, eating, and resting. That’s it.

Now, genetics can make it easier or harder to build muscle and lose fat.

Some people have naturally high testosterone and growth hormone levels, which means faster muscle growth and an overall leaner physique. Some people’s bodies mobilize fat stores more effectively than others, making fat loss an easier endeavor.

Genetics also play a role in the shape of your muscles. Not all guys can have that perfect square chest or ridiculous bicep peak, and not all women can have a gravity-defying, perfectly round butt.

But none of these things are real limitations.

Who cares if you build muscle or lose fat slower than someone else? As long as you can see regular improvements and get to where you want to be, the added time is irrelevant. Regardless of the “quality” of your genetic programming in terms of fat loss, you can build the body of your dreams in a matter of a few years, and maintain it for the rest of your life.

And big deal if you can’t have the same aesthetics as your favorite fitness cover model. You can still look awesome and feel great, and that’s what it’s all about.

What do you think about how genetics affects our ability to build muscle and lose fat?  Have anything else to add? Let me know in the comments below!