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Can Your DNA Explain Why You Struggle with Cardio? Science Says Yes, and Here’s by How Much

 Written by 

Julien Raby

 Last updated on 

Researchers have found that our genes play a big role in how we respond to exercise. 

They identified 13 genes that influence three main areas of fitness: cardiovascular fitness, muscular strength, and anaerobic power. 

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These genes can explain 44% of the differences in cardiovascular fitness, 72% in strength, and 10% in power among people who were not previously trained.

Cardiovascular Fitness and Genes

Cardiovascular fitness, or how well your heart and lungs work during exercise, improved by about 11% with regular aerobic exercise. Several key genes affect these improvements:

ACE Gene: Think of the ACE gene as a regulator for your blood pressure and heart health. Different versions of this gene (called polymorphisms) can all help boost your cardiovascular fitness when you exercise. It’s like having different models of a car engine that all make your car go faster.

Other Genes: Genes like COX4I1, CS, and HADH are involved in how your body produces energy during exercise. For example, COX4I1 helps with the energy production in your cells, while CS plays a role in processing fats and sugars for energy. HADH helps break down fats to use as fuel.

Muscular Strength and Genes

Muscular strength, measured by how much weight you can lift in one go, increased by about 22% with strength training. Six key genes play a significant role in these gains:

AKT1 and mTOR Genes: These genes are like the master controllers for muscle growth. When you do strength training, these genes help your muscles get bigger and stronger by boosting protein production in your muscles.

ACE and VEGF-A Genes: The ACE gene, also important for heart health, helps with muscle strength too. VEGF-A, although studied with fewer participants, is another gene that helps improve strength, probably by supporting blood flow to muscles.

ACTN3 Gene: Known as the “sprinter gene,” ACTN3 helps with muscle power and strength. Even though its impact was smaller compared to other genes, it still made a noticeable difference in how much strength people gained.

Anaerobic Power and Genes

Anaerobic power, or your ability to perform short, intense bursts of activity, improved by about 12% with specific training. Genes had a smaller impact here, explaining only about 10% of the differences.

HADH and MAFbx Genes: HADH, which also helps with cardiovascular fitness, is important for anaerobic power too. MAFbx (also known as Atrogin-1) is involved in muscle repair and growth. Think of HADH as providing quick energy, while MAFbx helps rebuild muscles after hard efforts.

Practical Applications

These findings mean that knowing your genetic profile could help create a personalized exercise plan that works best for you.

Instead of following a one-size-fits-all approach, trainers could design workouts that match your genetic strengths. This way, you might see better and faster results from your efforts.


Genes have a significant impact on how we respond to exercise, affecting cardiovascular fitness, muscular strength, and anaerobic power.

By understanding these genetic influences, we can tailor fitness programs to individual needs, leading to more effective and personalized workouts.

Future research will help us understand these genes better and create even more customized fitness plans.

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