A woman lifting a barbell overhead in the gym.

Why is it easier for some people to build muscle definition?

Posted by for Strength

Some people can naturally build more muscle than others (which seems totally unfair), but apparently it all comes down to hormones and genetics.

If you’ve ever wondered why no matter how many weights you lift or personal training sessions you fork out for, your muscles never seem to grow larger and stronger – yet, your best friend, who doesn’t run or swim or cycle or gym, has washboard abs all year round, we’re here to remind you that fitness looks different on everyone. 

Even if everyone started eating the exact same things and did the same amount of exercise, we wouldn’t all look the same. This is because our genetic inheritance influences everything from bone structure and body shape to weight and muscle mass differently.

Some bodies are simply genetically primed to put on muscle more easily than others. 

Does diet have anything to do with it?

Building muscle mass and definition is hard work and also requires the correct diet.

“I’m pretty sure that most of us know if we want to build muscle in strength and size that we need to consume protein,” says KOBOX instructor Zoe Purpuri. “Eating protein-rich foods is something that will aid muscle growth.”

If you are exercising to build muscle mass or definition, you don’t need to restrict calories. It’s best to aim for a balanced diet of proteins, carbs, and fats.

Do hormones also play a role in someone’s ability to gain muscle?

Testosterone plays a big role in muscle protein synthesis and therefore in ‘building muscle’,” explains Esther Goldsmith sports scientist at Orreco, FitrWoman. “It may also be associated with insulin growth factor-1 (IGF-1) which also has a role in muscle mass increase (both are ‘anabolic’ hormones or steroids).”

Most of us know that testosterone is a male sex hormone, and while females do have testosterone, our natural levels are much lower than those seen in males, she explains. “The normal ranges of serum testosterone in females are about 0- 2.1 nmol/L, whereas male normal ranges are 9-40 nmol/L (although these ranges may vary). As females typically have much lower testosterone levels, this is one of the big reasons why females may find it hard to ‘build muscle’.”

Remember, women usually have a higher body fat percentage

In regards to the aesthetic of muscle, females typically have a higher body fat percentage, says Goldsmith, “which, for most, is necessary to maintain a healthy hormone balance and regular menstrual cycle, and this will affect how muscles ‘look’. Muscle strength is not just dependent on muscle mass either, so just because you don’t look bulky or muscly doesn’t mean you’re not strong.”

Fitness blogger Alice Liveing recently posted an all-important reminder that having visible abs doesn’t necessarily mean you’re fit and healthy, it just means you have low body fat.

What about periods?

“It is also important to acknowledge that energy availability, menstrual cycle phase and hormonal contraceptives (as well as other medication) can affect testosterone levels and may play a part in whether you can build muscle or not,” says Goldsmith.

“‘If you are in a state of low energy availability (expending more energy than you are consuming), and your menstrual cycles have stopped, then testosterone and IGF-1 levels may be suppressed, which could put a halt to any ‘gym-gains’ and mean you are more likely to plateau, rather than adapt to the exercise you are doing.”

Everyone’s body is built differently – It’s all in the genes

The makeup of our muscle fibre varies according to genetics, explains Purpuri. “This you have no control over.” 

“We all have slow and fast-twitch muscle fibres,” she says. “Fast-twitch muscle fibres are used for power and strength – high-intensity movements or exercises – and grow faster and bigger.”

So if you’re someone who has a higher percentage of fast-twitch fibres, you’re going to be able to gain more muscle definition, at a higher rate – purely because of your genes. 

Our best advice? Remember that every body is different, so instead of comparing yours against what someone else’s looks like, try to think about all the incredible things your body is capable of (abs, or not).

Want more at-home workouts? Follow @StrongWomenUK on Instagram for the latest workouts, delicious recipes and motivation from your favourite fitness experts.

Image: Getty

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