New Study Shows Kids Get Athletic Abilities From Their Mom

Every runner knows the feeling of pushing through the last mile. Your legs burn, your lungs heave, and your heart pounds against your ribs.

We often attribute our ability to keep going to our training, our grit, or perhaps the athletic build we inherited from a sporty father.

However, a growing body of scientific evidence points to a surprising reality: the biological machinery that powers your run the "engine" of your cells is a gift inherited exclusively from your mother.

While your height, muscle structure, and skeletal frame are a genetic cocktail mixed from both parents, your endurance capacity relies heavily on something called mitochondrial DNA.

New and ongoing studies into genetics and physiology are reshaping how we understand athletic inheritance, suggesting that if you are a runner, you owe a massive debt of gratitude to your mom.

The Powerhouse of the Cell: Understanding Mitochondrial DNA

To understand why your mother is the key to your running success, we have to zoom in to the cellular level. Inside almost every cell in your body, there are organelles called mitochondria.

You likely remember them from high school biology class as the "powerhouse of the cell."

This nickname is accurate because mitochondria are responsible for creating adenosine triphosphate (ATP), the chemical energy currency that fuels muscle contractions.

When you run, especially during endurance events like marathons or half-marathons, your body relies heavily on aerobic respiration. This process happens largely inside the mitochondria, where oxygen and nutrients are converted into energy.

The more efficient your mitochondria are, the better your body is at utilizing oxygen a metric often measured as VO2 max.

Here is the genetic twist: unlike the DNA in the nucleus of your cells (nuclear DNA), which is a 50/50 split from mom and dad, mitochondrial DNA (mtDNA) is inherited strictly from your mother.

When fertilization occurs, the sperm contributes its nuclear DNA, but its mitochondria (located in the sperm tail) are usually destroyed or left behind. The egg, however, is packed with the mother's mitochondria.

This means every single mitochondrion in your body right now is a direct clone of your mother's, which was a clone of her mother's, and so on.

If your mom had mitochondria that were highly efficient at processing oxygen, you likely inherited that same high-performance engine.

The Science: Evidence from Animal and Human Studies

The theory that endurance capacity is maternally linked is not just speculation; it is backed by rigorous scientific investigation.

One of the most compelling areas of research comes from studies on "Intrinsic Exercise Capacity."

Researchers have long used rat models to study genetics because their generations are short, allowing scientists to track traits over time.

In a pivotal study discussed in journals like Physiology and Genomics and findings related to the HERITAGE Family Study, scientists observed that while training improves everyone, the baseline ability to move oxygen the intrinsic aerobic capacity has a strong genetic component.

A specific study published in PMC (PubMed Central) titled "Intrinsic Exercise Capacity and Mitochondrial DNA Lead to Opposing Vascular-Associated Risks" delved into this relationship.

The researchers bred lines of rats with high aerobic capacity (HCR) and low aerobic capacity (LCR). They found that the mitochondrial genome played a significant role in vascular physiology and energy output.

The study highlighted that animals inheriting the mtDNA of a high-capacity mother displayed improved vascular function and better metabolic profiles.

In contrast, those with "low-capacity" mitochondria struggled more with energy efficiency and had higher risks of metabolic issues.

Key takeaway for runners: This suggests that the "ceiling" of your aerobic potential how high your VO2 max can go and how efficiently your body burns fuel is heavily influenced by the specific mitochondrial genes you received from your mother.

You can read more about the specific mechanisms in this study here.

Dad Gives the Chassis, Mom Gives the Engine

It is important to clarify that your father’s genetics are not useless when it comes to running. A useful analogy used by sports geneticists is the car comparison.

Think of your body as a race car.

• The Chassis (Nuclear DNA): This comes from both parents. It determines your height, your bone density, your limb length, and your muscle fiber composition (fast-twitch vs. slow-twitch). If your dad was a 6-foot-tall sprinter, you might inherit his long legs and explosive muscle fibers (influenced by genes like ACTN3).

• The Engine (Mitochondrial DNA): This comes from mom. The engine determines how much fuel you can burn and how long you can keep the car moving at speed.

If you inherit a "Ferrari chassis" (great legs and fast-twitch muscles) from your dad but a "moped engine" (inefficient mitochondria) from your mom, you might be a great sprinter but struggle with the marathon distance.

Conversely, if you have a "standard sedan chassis" but a "Formula 1 engine" from your mom, you might not look like a supermodel athlete, but you will be the one passing everyone at mile 22 because your body is incredible at producing energy.

This distinction explains why some athletes are naturally gifted at endurance sports (cycling, distance running, triathlon) while others excel at power sports (football, weightlifting, sprinting).

The endurance athletes are often the ones who won the "mitochondrial lottery" from their maternal line.

Prenatal Programming: It Starts Before You Are Born

The "Mom Effect" goes deeper than just the DNA she passes down. Recent discussions in sports science have highlighted the concept of fetal programming.

This field of study suggests that the environment inside the womb can switch certain genes on or off, affecting the child's future health and athletic ability.

A recent buzz in the medical community, highlighted by articles discussing findings in Medicine & Science in Sports & Exercise, suggests that a mother’s physical activity level during pregnancy can positively influence the fetus.

Mothers who exercise while pregnant may actually boost the vascular development and mitochondrial density of their unborn children.

This means if your mom was active whether she was jogging, walking, or doing aerobics while she was pregnant with you, she might have primed your cardiovascular system for success.

This is separate from genetics; it is an environmental head-start that only a mother can provide.

Does This Mean Training Doesn't Matter?

Absolutely not. While studies like the HERITAGE Family Study show that about 50% of your baseline VO2 max is genetic, the other 50% is entirely up to you.

Genetics determines your potential, but training determines your reality.

You might have inherited a world-class engine from your mother, but if you leave that engine in the garage (i.e., you sit on the couch and never run), it won't matter. Conversely, someone with "average" genetics who trains consistently, eats well, and rests properly can often outrun a "gifted" athlete who is lazy.

However, at the elite level where everyone trains hard and eats perfectly the winner is often decided by that genetic edge.

That is where the mitochondrial efficiency inherited from mom becomes the tie-breaker.

The "Warrior" Gene and Nuclear DNA

While we are focusing on moms, we must acknowledge the complexity of genetics.

There are nuclear genes that influence endurance too, such as the ACE gene and the PPARGC1A gene. These regulate how your muscles use oxygen and how your blood vessels constrict. Since these are nuclear genes, you get them from both parents.

However, the mitochondrial function is the bottleneck of endurance.

You can have all the vascular capability in the world, but if your mitochondria cannot process the oxygen delivered to them to create ATP, you will fatigue.

This is why the maternal inheritance factor is so uniquely critical for long-distance runners.

Summary: Go Hug Your Mom

The next time you crush a PR, cross a finish line, or simply enjoy an easy Sunday long run, take a moment to appreciate where that energy is coming from.

Your ability to lace up your shoes and endure the miles is a complex interplay of training, nutrition, and mindset. But biologically, the fire that fuels your run was sparked by your mother.

She gave you the mitochondrial DNA that powers every single stride.

Whether she was an Olympian or just someone who kept moving, her genetic legacy is beating in your chest and powering your legs.

Scientific References:

• Intrinsic Exercise Capacity and Mitochondrial DNA Lead to Opposing Vascular-Associated Risks: https://pmc.ncbi.nlm.nih.gov/articles/PMC7749784/
• Mitochondrial DNA and Elite Athletic Performance (Review): https://journals.physiology.org/doi/full/10.1152/physiolgenomics.00029.2011
• Genetic Influence on Athletic Performance (NIH): https://medlineplus.gov/genetics/understanding/traits/athleticperformance/