The Genetics of Fitness

Research suggests that there is a definite link between sporting capabilities and genetic makeup. Ian Craig explains.

Have you ever wondered what your genetic potential might be in sport? Some of you might already have found out, having excelled at a particular sport when you were younger, or even currently. Some of you might have no idea, but have just followed your friends or your nose into the multi-sport disciplines; even within multi-sport though, you have the choice to stay short and nail the sprint triathlon or go long and complete Ironman. Then there are those individuals who are a bit more confusing. I’ve trained with athletes who were provincial-level swimmers as kids over distances as short as 100 m, but put them on a bike and the further the better, thank you very much. It begs the question – can we have both sprint and endurance capabilities?

If we look at my old sport of running, the answer is almost certainly ‘no’. No matter how much endurance training you put Usain Bolt through, he would never take on Haile Gebrselassie over a marathon. And vice versa; Haile could never compete with Usain in anything less than 400 m. Having said that, however, Gebrselassie could comfortably beat most provincial level 400 m runners, such is the range of the man’s talents.


So if you were to know about your genetic potential, what would it tell you? From a simple swab of your cheek it is now possible to elicit your weighting of power and endurance genes and how much sporting potential you have in each area. Figure 1 displays the relative power and endurance weightings of two athletes. It would appear that Bill is more likely to excel at endurance sports because 71% of his overall genetic power/endurance potential is allocated to endurance compared to 52% for Ben. However, when you look at the two athletes’ endurance scorings in Figure 2, Ben has a superior overall rating, suggesting that he is more likely to excel at endurance activities as well as power sports.


How do we come up with these ratings? Since 2003, when the human genome was finally mapped to completion, research within the genetics of sporting performance has been prolific. It is now thought that a high percentage of the variance in athlete status is explained by additive genetic factors. For instance, a Russian study in 2009 looked at multiple genes and endurance performance in 1423 athletes compared to 1132 controls. The researchers found that 66% of the elite endurance athletes were carriers of eight or more of these endurance-related genes.

Genes have now been coded and studied which can help an athlete or their coach to choose their endurance and power training sessions, understand how quickly they are likely to recover from training sessions, and be aware of their genetic susceptibility for tendon and other soft-tissue injuries. It is a contemporary notion that prescription exercise regimens can potentially be tailored to the genotype of the individual. A Rugby League team in Manly, Australia have claimed that they gained a competitive advantage over their rivals by using genetic testing to design the players’ training programmes in an individual way.

The Genetics of Fitness

The Genetics of Fitness

The Genetics of Fitness


Assuming you’re an endurance athlete, what happens if you’ve got a stronger genetic power profile compared to endurance? For one, I would tend to suggest that if it is peak performance that you’re after, then stick with the shorter events. Secondly, I would suggest putting a good amount of strength and speed work into your programme – at least two sessions/week: Within an endurance schedule, it is important for you to cultivate your speed and strength. Top endurance athletes are not slow – speed at short distances in most cases translates to speed at the longer distances.

Even if two athletes are training for the same race – let’s say the Argus Cycle Tour – one cyclist may thrive on 300+ km/week of steady riding while the other cyclist might actually be best staying below a total weekly distance of 100 km, but inserting hard sprint intervals, hill reps and weight training. In other words, it’s important to know your strengths. With the genetic information, you can also tailor your recovery periods specifically to your genes. If it is revealed that you have a stronger inflammatory response to heavy training, I would suggest longer recovery periods between sessions and also an eating and supplement plan that is anti- inflammatory and antioxidant-rich in nature.


South African genetics company DNAlysis launched its cutting edge test DNA Sport in 2011 and it has been kept well up-to-date as new genetic information has appeared in the research. The test is conducted via a simple cheek swab, which is sent to the lab in Johannesburg.

Editor's note: For further information about DNA Sport genetics testing, see our report on The Genetic Testing Laboratory: DNAlysis

continue to top