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How DNA Testing Can Determine Your Genetic Limit to Muscle Growth

Margaret Etudo
Three people doing a high plank in the gym
It’s no news that lifting weights and consuming protein shakes can help you build muscle. However, research has shown that no matter how much you train, you can only build a certain amount, thanks to your genes.

Your genes determine how much muscle you can build. This is why some people find it easier to lose weight and gain muscle than others. In this post, we'll take a closer look at how genetics limit muscle growth and give you a few tips to work around it in order to build as much muscle as genetically possible—naturally! Let's dive in.

» Interested in an at-home DNA test? Check out our top picks for the best DNA test kits and companies.

Is There a Genetic Limit to Muscle Growth?

Experts have found that there are many genes that control muscle growth and development. However, this research is still underway, and we could still discover more genes that affect muscle growth in the future. That being said, let’s take a look at the genes that have a hand in increasing muscle growth.

A 2018 study on laboratory mice found that that three genes (Asb15, Klf10, and Tpt1) increase muscle fiber and promote growth. Another study shows that ACTN3 is one of the many genes that affect muscle strength. Unlike athletes, most people have a defective ACTN3 gene, which means they are not able to produce the protein that helps with strength and bodybuilding.

Despite the fact that some genes favor muscle gain over others, there is a genetic limit to muscle growth. Scientists prove this using the fat-free mass index (FFMI). The FFMI measures your lean body weight with respect to your height. Studies show that a person cannot have an FFMI higher than 25 to 26 without taking steroids.

» Thinking of taking an at-home DNA test? Here's what you should know first.

4 Genetic Factors That Affect Your Muscle Growth Limit

So, we've established that people with better genetics would find it easier to grow their muscles, but why is this the case? The following factors influence how much muscle you can build.

1. Height and Bone Structure

Taller men with large bone structures find it easier to build muscle than shorter men with smaller bone structures. A study shows most men gain about 5 kilograms of muscle for every kilogram of bone, while women gain 4 kilograms for every kilo of bone.

2. Muscle Shape

A muscle is made up of the belly and tendon. The belly expands and contracts during movement and exercise, and the tendon connects the muscle to the skeleton.

Muscles grow wider and not longer. Therefore, the longer the belly and shorter the tendons, the more muscle mass you can gain.

3. Muscle Cells and Fibers

Your muscle cells increase as you exercise, directly impacting muscle growth. Muscle growth can also be The size of your muscle cells can also determine muscle growth.

In addition, those who have more muscle fibers have an easier time increasing their speed and strength and make better athletes.

4. Testosterone

Testosterone is the main hormone produced in the body, and it plays an important role in muscle growth and maintenance. People with high testosterone levels have higher satellite cell activity, which increases their muscle mass.

» Learn more about reading and interpreting your DNA test results.

The Role of Genetics in Muscle Decline

Just because genes can improve muscle growth doesn’t mean there aren’t ones that do the opposite. Your genes play a role in muscle decline in terms of size and strength. For example, myostatin is encoded by the MSTN gene and limits muscle growth.

Building muscle also becomes relatively difficult when testosterone levels reduce. Most times, the hormone reduces as a result of aging.

» Want to learn more about your health? Find out more about how your ancestry and ethnicity affect your health.

How DNA Testing Can Help

DNA testing can help you determine what is possible when it comes to exercising, building muscle, and losing weight. DNA tests can help you determine your muscle growth capacity by testing the following:

  • Weight loss genotype
  • Body composition type
  • Testosterone levels

Weight Loss Genotypes

DNA tests will tell you what type of weight loss genotype you have, which tells you how you gain or lose weight and respond to macronutrients. These genotypes vary from low to enhanced.

An enhanced genotype means you need more strength training and proteins to avoid losing muscle mass. People with normal genotypes will get optimal results from exercise. If you have a low genotype, you will need to double your training to gain muscle.

Body Composition Type

DNA tests analyze your body composition type, i.e., how your body responds to strength training. People with an enhanced body composition find it easier to build muscles with the right exercises. However, more people fall into the normal category.

Testosterone Levels

Testosterone is a hormone that greatly affects muscle growth. Men have more of this hormone, which is why they have an easier time building muscle.

Tests for this hormone come out as "more likely," "normal," or "less likely." If yours is "more likely," you have a higher chance of having low testosterone levels.

» Check out these 10 things a DNA test can tell you about your nutrition.

Tips for Developing Muscle Naturally Based on Your Genetics

Developing muscle naturally pays more than using supplements and drugs like steroids. If you don’t want to risk your health and overall physique, working with your genetics to build muscle naturally may be your best bet.

Depending on the type of DNA test, different methods can help you choose the best ways to develop muscle naturally.

For Weight Loss Genotypes

People with a below-average genotype should engage in resistance training to increase their strength. People with a normal or enhanced genotype should do higher-intensity workouts to grow their muscles.

For Body Composition Type

People with an enhanced body composition type should focus on strength training and work out about three times a week. If you have a normal body composition type, you should work out twice a week and focus on strength training and cardio.

In the case of a below-average body composition type, strength training won’t cut it. It’s best to focus on heavier weights to boost metabolism, burn fat, and grow muscles.

Tips for Testosterone Levels

If you have low testosterone levels, try full-body strength training to increase your levels. You can also consider doing high-intensity interval (HIIT) workouts to get in some cardio.

Maintaining a healthy lifestyle, sleeping well, and avoiding alcohol can improve testosterone production and increase muscle growth.

» Learn more about what DNA results can tell you about your health.

Bottom Line

Certain traits can be purely genetic, even how your body builds muscles. Some people have better genes that allow them to increase their muscle growth faster than others. Regardless, there is a genetic limit to the muscle mass you can naturally attain.

Getting a DNA test can help you determine your genetic limit to muscle growth. Through reputable DNA companies like Vitagene and MyHeritage, you can easily take an at-home DNA test to find out how your genetics affect your muscle gain and optimize your bodybuilding journey.

» Trying to lose weight? Try these meal delivery kits for weight loss.

Margaret Etudo
Margaret Etudo is a medical writer specializing in healthcare, pharmaceuticals, and various medical fields, with a Bachelor of Pharmacy Degree in progress at the University of Lagos. Her experience includes crafting articles for top10.com, WebMD, and Medical News Today, where she exhibits her ability to simplify complex topics in areas like respiratory, mental, and sexual health. Margaret makes it her mission to break down complex medical information for the everyday reader.