How your DNA can determine your running performance

Muna Lee knows her great strength lies in running short distances – after all, she’s twice competed for the United States at the Olympics, in both the 100 and 200 metres. But sprinters need more than speed to succeed.

Now Lee is putting a greater focus on building endurance and devoting more time to recovery, thanks to results from DNA testing. Two years ago, she submitted a swab of saliva to the Canadian company Athletigen. 
The analysis 
she received provided training suggestions based on several genotypes, including HIF1A (which indicates how much oxygen the body delivers to muscles). Already, she feels stronger and better rested. ‘I wish I had done it sooner,’ she says.

Lee trains with more than 100 other athletes at Altis, a track-and-field training facility in Phoenix, Colorado, US. Coaches there have collaborated with scientists at Athletigen for the past two years to profile athletes and understand the links between genetics
 and performance, says Altis CEO and founder John Godina, who’s won Olympic silver and bronze medals in the shot-put.

‘As an organisation, we’re trying to push the boundaries regarding
 the amount of data and knowledge we can gather about the athletes,’ says Godina. ‘We still have our experience as coaches and the athletes’ race experiences as well. The genetics is just another way to turn the sculpture to look at the other side and see what’s going on.’

Cracking your code

You don’t have to be an Olympian to access this data. Companies such as DNAFit and FitnessGenes offer DNA testing to everyday athletes. The specifics vary, but most companies promise to assess genes related to muscle development, recovery time and injury risk – and offer a training plan (and sometimes a diet) tailored precisely to your DNA.

(Related: 7 ways to have a running breakthrough)

Not everyone has bought into the theory. Genetics researchers say these claims outpace the evidence. In fact, in a recent issue of the British Journal of Sports Medicine, a consortium of experts released a statement steering consumers away from these services. DNA influences such outcomes as your 5K time and body-fat percentages. But unlike some inheritable diseases that hinge on a single gene mutation, the DNA code underlying sports performance has proved harder to crack, says Linda Pescatello, a scientist at the University of Connecticut, US, who’s spent years trying.

In some cases, genes shown in one study to influence athletic traits haven’t held up to further scientific scrutiny, she says. And in others, the effects of the various mutations that scientists do understand pale in comparison with those that they don’t. ‘Say you have 12 puzzle pieces out of hundreds or thousands,’ says David Epstein, author of The Sports Gene: Inside the Science of Extraordinary Athletic Performance. ‘You’re giving someone this measure that looks like you are telling them a balance of percentages inside 100 per cent, when really, that entire 100 per cent might be less than one per cent of what’s actually important.’

Racing the clock

Pescatello predicts it will be decades before scientists truly understand genetics well enough to derive useful, specific training guidance. But athletes such as Lee – who, at 35, probably won’t get another shot at the Olympics – don’t want to wait. Godina says he understands the scepticism but sees little downside for his athletes.

(Want to read more articles like this? Subscribe to Runner's World here!)

Because he can monitor and understand so much of what’s happening in their lives, he can help them implement the results earlier than other runners might – he hopes to have even more useful insights from the testing within 
the next two years. ‘The genetics is an aspect of the whole,’ says Godina.
‘If you’re seeking to get 
a tenth of a per cent improvement and you’ve exhausted all the other pathways, if genetics can provide you with that tenth of a per cent of insight, the testing has done its job.’

4 ways your genes could inform your running

1/ SPEED VS ENDURANCE

What you'll learn: Genes influence your balance
 of fast- and slow-twitch muscle fibres, which play a crucial role in whether you’ll excel at tearing up the track in a 100m race or will be able to keep going for 26.2 miles without falling apart. For instance, most elite sprinters do not have a particular variation of a gene called ACTN3, which is detrimental to sprint performance.

Is it helpful? Having this genetic variation only tells you that you won’t challenge Usain Bolt in a sprint, not whether you’ll qualify for the Boston Marathon – and certainly not how to best train for it, says geneticist Stephen Roth, of the University 
of Maryland, US.

2/ RECOVERY

What you'll learn: Testing companies analyse 
genes such as IL-6, an inflammation marker, 
and they can also recommend an ideal amount of downtime.

Is it helpful? Many factors contribute to
 your recovery rate, including how hard you ran and what you ate afterward, says Linda Pescatello, of the University of Connecticut, US. To track how it all fits together in real time, use a tool such as Ithlete – which combines a fingertip sensor with an app (£44.99 and £6.99, respectively) – to keep tabs on your heart-rate variability, which can indicate overtraining.

3/ INJURY RISK

What you'll learn: A certain copy of a gene called COL1A is linked to ruptures in the knee’s anterior cruciate ligament (ACL). And 67 snippets of DNA influence your odds of developing fractures. Your genes probably explain part of your propensity for injury, says scientist Dr Stuart Kim of Stanford University, US.

Is it helpful? The genetic markers that scientists have pinpointed probably explain only a small percentage of the total genetic picture – what we don’t know greatly outweighs what we do know. For now, look to the past – unfortunately, having one injury places you at high risk for a repeat occurrence.

4/ BODY TYPE

What you'll learn: Most genetic tests can identify so-called obesity genes, says Pescatello. Certain genetic variations can boost your risk, perhaps by influencing your appetite or propensity for fat storage.

Is it helpful? Pescatello says many other genes – plus, of course, lifestyle choices such as diet – play a big role in how easily and comfortably you squeeze into your running tights. If you have a family link to obesity – or suspect it, based on a glance around the Christmas dinner table – use it as motivation. As little as an hour of running per week will tip the scales in your favour, even if you’re genetically prone to obesity.