Winning combination: Is athletic potential governed by a genetic code?

By Cary Davies

26 August 2024

The answer, of course, is multifaceted.

There is much deliberation about whether sporting skill stems from the inheritance of physiological talent or psychological discipline. The role of inherited habits has ample standing in the nature versus nurture debate across most domains, but how much weight the genetic code carries in the sporting arena poses an extremely interesting question.

Genetics has been extensively studied in exercise research, and the findings suggest that DNA variation cannot fully explain athletic success1.

However, the achievement of elite athlete status seems most plausible when physiological and psychological pillars of excellence meet.

Does a ‘sporty’ gene exist?

In an attempt to find correlations between specific genetic traits and athletic performance, researchers have conducted genome-wide association studies (GWAS) to investigate the genetic code of elite athletes.

The results indicate that athletic performance is likely shaped by a complex interplay of genetic factors rather than a singular beneficial gene. Furthermore, genetic testing for athletes can categorise genes into sub-groups that influence different areas of athletic ability, such as endurance, power, and baseline fitness.

Scientific estimates suggest that genetics accounts for approximately 66% of athletic success.1 However, genetic advantage can be enhanced or reduced by various sliding variables, including body composition, general health, mental health, nutrition, ergogenic aids, training environment, and social support.

In this regard, lifestyle genetic testing can provide a competitive edge to athletes through individualised feedback on their genetic strengths and limitations.

Moreover, as biological knowledge increases, so does the power of prediction. DNA profiling can be used to inform exercise design and optimise performance potential.

The suggested scope of DNA influence sparks enough interest for deeper investigation

A 2023 review of scientific literature revealed that as many as 251 different DNA polymorphisms (genetic traits) are associated with the performance capacity of athletes across a vast range of nationalities. 1

While further research aims to narrow the playing field, visionary companies such as 3X4 Genetics provide a simple translation of foundational genetics relevant to sports performance.

Although a 3X4 Genetics Test will not predict performance outcomes per se, the insights therein can provide individual empowerment and training direction. Click here to learn more.

How genetic testing can be used to tailor sports training strategies

Our genes play a role in oxygen delivery (VO2max), muscle fibre function, ATP production, mitochondrial biogenesis, circadian rhythm, and the inflammatory response to exercise.

Thus, genetic testing for athletes provides insights into the unique physical aptitude of an individual, which can be used to instruct various aspects of training, from progressive loading recommendations to peak training times and specific recovery requirements.

DNA testing can also gauge the performance-enhancing effect of caffeine, the risk of certain nutritional deficiencies, and the associated risk of muscle cramping - each of which may differ between genotypes.

Therefore, if athletic training is planned according to recognised genetic parameters, the expected outcome would be the attainment of optimal health, strength and fitness, at the most physiologically appropriate rate of progression, with minimal injury risk.

How DNA variants influence athletic potential

Athletic ability is influenced by two categories of physical fitness: musculoskeletal fitness (strength) and cardiorespiratory fitness (endurance capacity).

  • Musculoskeletal fitness is influenced by the composition of skeletal muscle, which consists of slow-twitch and fast-twitch muscle fibres. The ratios of these fibres can vary dramatically between genotypes. A higher ratio of slow-twitch muscle fibres is associated with enhanced endurance capacity, while fast-twitch muscle fibres are linked to greater power potential.2 Thus, athletes with a higher proportion of fast-twitch muscle fibres are likely to display superior adaptations to strength training and enhanced abilities in sprinting, jumping, and weightlifting.
  • Cardiorespiratory fitness is influenced by the body’s oxygen-carrying capacity - otherwise known as VO2 max - which is also impacted by genetics. Certain gene variants can predict prolonged aerobic sustainability and athletes who carry such variants are likely to display superior endurance capacity, achieve a higher VO2 max, and excel in long-distance events.

Establishing genetic advantages and limitations can improve motivation

Despite the definitive nature of DNA testing, the interpretation of genetic code will not limit athletic potential or rule out the possibility of a competitive sports career. In fact, it may achieve the opposite.

Understanding their own genotype will empower athletes with the foresight of how their bodies will respond to different types of exercise. For example, runners who do not carry a genetic advantage for endurance will need to allow for a longer training period before a marathon than those whose genes allow for faster improvements in VO2max.

Similarly, the expected time frame for the visible results of weight training to emerge will depend on genetic variation. In this way, genetic testing can be used to manage expectations, direct training towards areas of inherent strength, and refine preparation strategies for competitive events.

Injury risk and the accurate prescription of rest can also be determined by DNA

The role of genetic variation in injury risk has been less extensively researched, yet it holds immense promise in protecting athletes from load-associated injuries, especially those who are genetically prone to inflammation.

Post-training inflammation and oxidative stress are a natural response to exercise, but different bodies may exhibit different levels of inflammatory stress, even with identical training.

Increased frequency and intensity of training are not always correlated with performance gains. On the contrary, they can create setbacks for those genetically predisposed to inflammation and injury.

In such individuals, optimal exercise design might include mandatory rest days in between intensive training sessions; a greater focus on slow endurance training, and fewer heavy resistance workouts.

Understanding individual recovery requirements may be just as important for athletes as pushing for their personal best. If a training load is too high, with insufficient post-training recovery, the consequences could be potential injury and reduced motivation due to muscle pain and fatigue.

Another way to look at exercise recovery is through the lens of adaption to training. In other words, without adequate recovery, the body will not be well-equipped to handle progressive loading. However, since the capacity for physiological stress in genetic, exercise recovery planning can be customised.

Genetic testing provides access to the fine print of key performance guidelines

DNA profiling can be used to determine the expected physiological response to different types of exercise, guiding periodised progression and offering strategic training advice.

In summary, while athletic potential cannot be predicted by genetics alone, it can certainly be enhanced by playing to genetic strengths.


References:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10298527/
  2. https://www.physio-pedia.com/Muscle_Fibre_Types