Do genetics play a role in building muscle?

8 min read

Role of Genetics in Bodybuilding - Devoted Blog - Devoted Gym Wear | Sportswear

I can’t put on muscle because of my Genetics?

Sound familiar? It might because many people who work-out, even we ourselves sometimes blame genetics for stunt muscle growth. However, does this statement hold any truth?

Do genetics actually play a role, or is it just a lazy man’s excuse to why he/her isn’t in shape?

We’re gonna talk about all of this here. What role does genetics play, how can you test out your levels of genetic limitation etc?


Do genetics play a role in building muscle?


Yes, don’t let anyone tell you otherwise. We all are born with a set of genes that are written in stone. You can alter them to some extent, like 2-5% maybe. But not enough to make a difference.

Does that matter? A big NO. Let's talk about these genes in more detail.


What all is actually controlled by genetics?


We all have thousands of different genetics in us, however, as far as bodybuilding goes, the few main genetic differences that play a role are listed below.

  1. Composition of Fast twitch and slow twitch muscles
  2. Neuro efficiency
  3. Bone density
  4. Skeletal muscle
  5. Hormone Levels
  6. Satellite cells
  7. Genetic mutations
  8. Time taken by our muscles to recharge ATP.

Out of all of these, the most important one is the composition of fast twitch and slow twitch muscle fibers. Either way, we can’t alter any of these to an extent big enough to make a difference.


What are fast and slow twitch muscle fibers?


The more fast twitch muscle fibers a person has, the faster a person can build muscle. Slow twitch muscle fibers basically are the muscles that determine how long an activity can be continued for a period of time, for example running marathons. And on the other side, fast twitch muscle fibers are those that determine the power performance levels in activities, for example, running a 100m race.


How to know whether genetics are on your side or not?


To get a pretty much exact estimate of your composition of fast twitch and slow twitch muscle fibers, you’re gonna have to get a muscle biopsy. However, it’s really expensive, painful and shouldn't be on your bucket list. We at Devoted are gonna provide you an easy exercise to test out your composition of fast twitch and slow twitch muscle fibers.

This process is called the ‘80% Rule’. Here’s how you can perform this on your own. These are the steps

  1. Select your best compound exercise. Whichever one is your best, it might be bench press, squat, deadlift etc.
  2. Find your 1RM(1 Rep Max) for that exercise in pounds and let that weight be ‘X’.
  3. Take 80% of X in pounds, load it up and start performing that exercise to failure, with proper form and count your reps
    Note: Perform this exercise fresh, not in the middle/after a workout.


  1. Now as per your reps, you can measure your composition of fast twitch and slow twitch muscle fibers via the following;


  1. 1-3 Reps

Extremely fast twitch muscle composition

  1. 3-6 Reps

Majority fast twitch muscle composition

  1. 6-9 Reps

Little more fast twitch muscle than slow twitch

  1. 9-13 Reps

Normality, almost equal composition of fast and slow twitch muscle fibers.

  1. 13-16 Reps

Little more slow twitch muscle than slow twitch

  1. 16-19 Reps

Majority slow twitch muscle composition

  1. 19+ Reps

Extremely slow twitch muscle composition


By performing this simple test, you can know your approximate composition of fast and slow twitch muscle fibers.


So what all does this mean to me?


In conclusion, if you are currently in a situation where it seems like your muscle growth has got stuck. The best solution to that would be to change up your workout. Stop doing your normal split and change it up. There are a million ways to make changes in your workout. Start a cycle with really low reps(4-6), or a cycle with really high reps(20-50). Change up your rest in between reps to 30 seconds or go to the other side and take 2 mins rest. Start performing different exercises, perform 4 sets instead of 3 etc.

In the bodybuilding world, change equals growth. Read our other blog about the 4 fundamentals of transformation to know more about how to build muscle faster.

And the last thing before signing off, stop comparing yourself to the most muscular guy in the gym and stop blaming genetics for the same. You can’t compare your chapter 2 to someone else’s chapter 20. That guy has probably been working out for over a few years, with Devotion. And do remember to check out our line of fitness clothing, which will help you to perform better and look better, with Devotion.

Stay Devoted.


  • Team Devoted

    Hi Binanda,

    Our Free Devoted Trainer will surely help you out here, link –


  • Binanda Saikia

    Give me a muscle grow complete routine.

  • Team Devoted

    Hi Anurag,

    Thanks a lot for your comment, we’re really glad that you liked our blog :D



    Nice blog

Leave a comment

Please note, comments must be approved before they are published

यह साइट reCAPTCHA और Google गोपनीयता नीति और सेवा की शर्तें द्वारा सुरक्षित है.