Is running ability down to effort or DNA? And can it be proved?

If you’re really serious about competitive running, there are companies that test your DNA to determine your sporting potential. But does it work?

Growing up, I was always the dumpy, unsporty one. Matt, my older brother, was the skinny one who did the running, jumping and anything requiring quickness and coordination. He seemed to excel with ease while I laboured away on a sluggish course towards sub-mediocrity. This pattern lasted until our late teens when Matt, being older, beat me to booze. While he was away on a year-long, round-the-world bender, I took up running — with a vengeance. It was time to turn the tables.

By the time Matt got back, I’d joined the local running club and was training every day. It turned out that becoming a competent runner didn’t require special talent, just lots of miles – driven on by the sense I was outrunning my former, slouchy self. Matt, visibly shaken by my transformation, threw himself into training to catch up – stymied by his three-kilo beer belly.

'The biggest shock is my aerobic potential, rated "low". OK, I'm no Mo Farah, but but surely my aerobic capacity is at least middling'

We’ll skip the gory details – the dozens of races where I beat Matt with ease – and fast-forward to 2012. I had been training consistently for six years by now. Matt was swiftly catching up, but I still had a clear edge in any race of more than10 miles, so I decided to step up to the marathon. After putting in the hardest three months’ training of my life, I came away with a shiny new PB of 2hr 28 min 46 sec.

The point is not to revel in my glory. My time was decent club standard but hardly impressive against “proper” British marathoners, let alone African elites. The point is, it was amazing for me, given my widely presumed lack of ability. If only I had realised sooner that I had the potential …

Imagine someone had tested my genes as a podgy kid and told me: don’t worry, you’re an athlete inside, it’s only your Sherbet Dip Dab habit holding you back. What wonderful reassurance and motivation that would have been. But wait. What if they had looked at my results and said: sorry, it’s not through lack of effort that you are sub-mediocre – it’s down to your DNA. What then?

I was intrigued to find companies offering to do just that – test my DNA to determine my sporting potential. Could it really work? I decided to find out.

I got in touch with DNAFit, the leading provider, and asked if they would blind-test my DNA plus a few other samples. To my surprise, they said yes. A call to some friends with connections in elite sport secured a sample from a multi-Olympian and world champion runner (on condition I wouldn’t reveal his identity) — let’s call him Mr Swift — and another from pro cyclist James McLaughlin. If their results tallied with their achievements, I figured, DNA testing would be worth taking notice of.

A few weeks later the results were in. Swift’s read as follows: “Aerobic potential: medium”, which qualified as “an intermediate VO2max tendency”. Yet according to his physiologist, Swift’s VO2max is “above 77” – quite definitely not an intermediate score. Furthermore, the report deems his power/endurance profile as favouring power over endurance by a ratio of 70/30. Swift is one of the greatest endurance runners in the history of the sport. His injury risk, marked “medium”, is also at odds with the actual evidence. “He has had many, many injuries,” his physiologist confides. “I’d say his injury risk is untypically high.”

McLaughlin’s results are similarly at odds with his track record: his aerobic potential is rated “medium”, with a slight tendency towards power over endurance. “It doesn’t ring true at all,” McLaughlin tells me. “My VO2max is very high, nearly 82, and I’m a pure endurance rider – I fare far better in long, sustained efforts than in sprints.”

My own results also suggest a predisposition towards power rather than endurance, 56/47. This flies in the face of my running experience: I am hopeless at shorter, power-based events; the longer the race, the better I do (relative to others). The biggest shock is my aerobic potential, rated “low”. OK, I’m no Mo Farah, but surely my aerobic capacity is at least middling, or how could I have run a sub-2hr 30min marathon?

I owe it to DNAFit to give them a chance to explain – after all, they have been generous in blind-testing samples, opening themselves up to journalistic scrutiny. The company’s head of sport science is the former Olympic sprinter Craig Pickering, to whom I reveal the disparities between our results and our sporting track records.

“You almost certainly can’t use genes to tell who will be a good athlete or not a good athlete,” he responds. “There is no talent identification use in this.”

Fair enough, but our world-class marathon runner was rated as having “medium” aerobic potential.

“That’s a great example of how you can’t use genetics to tell you what sport you’ll be good at.”

OK, fine, so what can genetic testing tell us?

“What the tests and reports do is give you information on which to base your training, to have a better informed programme.”

Citing one DNAFit-supported study on a small group of athletes, Pickering says that the results provide enough information to guide training, either towards power (short, sharp) or endurance (longer, slower) sessions. This insight, he says, relates to genetically determined trainability – rate of fitness gain – rather than aptitude. Yet this wasn’t the impression I had been given by the reports, covered as they are with the word “potential”.

I stress my concern to Pickering that, had I received my apparently bleak results as a newcomer to running, my athletic ambitions might have been crushed. But he thinks I am missing the subtleties. “Because you have a low aerobic potential … we have options, we can fine-tune and target other areas like movement economy and efficiency.”