ReadWriteBody is an ongoing series where ReadWrite covers networked fitness and the quantified self.

Over the years, I’ve taken a quasi-scientific approach to fitness, trying a variety of exercise and nutrition regimens and analyzing the results. But I've longed for a more definitive approach than my patchwork of research and experiments.

Genetrainer, a British startup in the emerging field of fitness genomics, promises to deliver something like that: workouts customized to your personal genetic makeup. The company grew out of research that Ralph Pethica, a Ph.D. student, conducted at the University of Bristol with one of his professors, Julian Gough.

Here’s the basic science behind Genetrainer: Researchers have analyzed the human genome and found variations, known as single-nucleotide polymorphisms, or SNPs, related to various conditions and tendencies. In recent years, they’ve discovered several genetic markers related to body mass, exercise response, and nutrition.

DNA, Meet API

Genetrainer draws on that science, but it is also very much a creature of the Web. In 2012, two key events made Genetrainer possible: In April, Amazon started hosting the 1,000 Genomes Project, a repository of human DNA profiles, in a format that made it much easier for Web-savvy data scientists to analyze. And in September, 23andMe, a consumer-genomics company offering DNA tests, opened up its API, or application programming interface, to third-party developers.

At the time, ReadWrite founder Richard MacManus predicted that 23andMe's API “will hopefully enable me to do useful things with my genetic data.” As usual, MacManus was right.

Because 23andMe handles the actual laboratory testing, and 1,000 Genomes offers a baseline population to compare against, Genetrainer can focus on analyzing its users' genes and mapping them against the latest available research. 

That matters because it means Genetrainer can offers its service at a lower cost than predecessors who have tried this before. A similar company, XRGenomics, offered its own fitness-oriented DNA test for approximately $315. While it drew some press coverage, its website is now offline and its Twitter and Facebook accounts appear inactive. (Update: After we published this article, XRGenomics’ website came back online and its Twitter account resumed posting, in part to dispute our reporting that the website was down. A cofounder, Jamie Timmons, told ReadWrite that the company had “paused” its sales for three months last year while it switched testing labs.) 

While the FDA has ordered 23andMe to stop offering health-oriented interpretations of customers' genes, it doesn’t appear it can stop customers like me from choosing to share our data with companies like Genetrainer that don't offer actual DNA tests.

I paid $99 to get my 23andMe test. Genetrainer plans to charge $79 for its test when it's available to the public. (Pethica let me view my results for free, with an incomplete, test version of the service; I am the first journalist to try the service.) 

How My Genes Have Trained Me

Some of what I learned through Genetrainer are things I've already gathered about myself. For example, I lack a sense of fullness after eating, a condition that's linked to a specific genetic variation. As a result, I rigorously log what I eat using MyFitnessPal so I don’t go over my calorie target. And my genetically determined circadian rhythm makes me a morning person, as anyone who views my sunrise photos of the Golden Gate Bridge on Instagram already knows.

Other results were surprising: I’m less likely to experience muscle soreness after workouts, which might explain my long gym stints. Basically, I don’t have to worry about overtraining, which is comforting to this gym rat.

Pethica, with my permission, took a deeper look at my genome and said I may have less response to weight-bearing exercise, which means that I could need to work out harder to gain strength and muscle than your average bear.

And, most intriguingly for a former fat kid, I appear to have fewer variations linked to an increase in body-mass index. That’s news to someone who’s struggled with his weight for most of his life, but it's interesting to contemplate the idea that my genetic destiny does not veer inexorably towards chunkiness.

Pethica says we may have to rethink the old saying about blaming our genes for our weight.

"It stops being an excuse, and you start looking for other things to blame—your lifestyle, the kind of foods you eat,” he said. "I'm not trying to tell you that genetics is everything. I'm just trying to tell you what we know at this point."

Some findings from my genetic test surprised me. Some findings from my genetic test surprised me.

 

Working Out My DNA

I grew accustomed some time ago to the idea that I'd have to watch what I eat and exercise hard for the rest of my life. But it's somehow comforting to know that this is just how I am, and that my body may actually be suited for the work I put it through.

And as Pethica points out, our DNA actually responds to environmental inputs, with genes getting turned on and off depending on a variety of factors. For example, researchers have found that exercise doesn’t just burn fat in the moment: It can change how our cells absorb fat, leading to long-term changes in body composition. 

"Our genes are just possibilities,” he told me. "Whether we turn them on or off is up to you."

My genes tell me I’ll be at the rowing machine a lot for years to come. My genes tell me I’ll be at the rowing machine a lot for years to come.

Genetrainer doesn’t stop with just offering analysis. It also prescribes a training plan. In my case, it suggested a mix of cardio and circuit-training workouts. That’s actually close to what I already do, so I likely won’t make many changes there. If I’d gotten this test years ago, though, it might have sped up my fitness progress considerably.

The most exciting thing I see in Genetrainer is its plan to link up your fitness data from a variety of sources, including fitness trackers like Fitbit and Jawbone Up and exercise apps like RunKeeper. Those connections may create a feedback loop of data that in turn inform the academic research Genetrainer relies on.

For example, if my genes say I'm a low responder to weight-bearing exercise, but my workout progression suggests otherwise, could that lead scientists to revise their results? (Many early genetic associations with disease risk or physical tendencies have failed to stand the test of time.) Or might it point to a new genetic marker they haven't analyzed yet?

It’s a glimmering of the potential that can be unlocked by putting genetic data online and using Web-scale data analysis. That's a big deal. But for me, it’s just one more glimpse into the workings of my body. And that matters, too.