You're just a cheek swab or a needle prick away from finding out if your body is programmed for endurance, built for power, or hard wiredto lift heavy. That's because the sophisticated lab tests that were once reserved for Olympians have gone mainstream, thanks to a bumper crop of new companies that offer to read your inner tea leaves—found in your saliva orin your blood—for about the cost of a high tech fitness tracker.
These tests can give you instructions on how you can change your habits to see results and maximize yourhealth," says Gil Blander, Ph.D., a cofounder of InsideTracker, which analyzes 30 bio-markers in your blood. For example, if you've ever won-dered about your ability to build muscle, there's a gene that can answer that. "There are indeed genes that are linked to your predisposition to develop certain typesof muscle fiber," says Avi Lasarow, the CEO of DNAFit, a company in London that uses saliva samples to test for genetic traits. "People with the R version of a genecalled ACTN3 have a higherlikelihood of developing fast-twitch muscle fibers [the stuff that sprinters have in large supply, as opposed to slow-twitch muscle fibers], but only if they do the right training." The R version of this gene has also been linked to anincreased growth of muscle mass when strength training, so they may see faster results from their reps, Lasarow says.
On the other hand, people without the R version need to approach workouts differently if they want to build muscle, he says. That may mean eating more protein and lifting moderately heavy weights for longer sets. (Or maybe you'll find out you have the anti-exercise gene which makes you hate the gym.) The point is, accordingto the gene and blood marker trackers, when you tailor exercise to your body's specific needs, you can ensure faster, longer-lasting results. So should you open wide or roll up your sleeve? Our guide can help you decide.
Blood, sweat,and saliva
All DNA and blood analysis companies basically work the same way: You go online to select your tests, then you provide them with the appropriate sample—saliva forDNA tests, blood for blood analytics. (For saliva, swab or spit and mail your sample to the company in a pre-paid envelope. To get blooddrawn, you can head to a local clinic, which will send it to the company.) The difference is inthe advice you get back: Each company offers particular categories that it tracks and has its own method for translating the results into a planof action. (See "The Fit Girl'sGuide to Testing Companies," below, for a quick overview.)
If you go the cheek-swab route, DNAFit offers astandard package for about $129. It tests 16 genes, generating information including your power-to-endurance ratio, which can help map out how much time you should spend doing intense exercise—intervals or shortbursts of heavy weight lifting—compared with steady-state workouts. (Other packagesalso include nutrition analysis and recommendations at an extra cost.)
Meanwhile, FitnessGenes offers several goal-based packages, including a starter system for getting in shape, a fat-loss system, and a muscle-building system, with recommendations extrapolated from analyzing 43 genevariations. For a slightly more comprehensive look at your health, but with a bigger bill ($499), Simplified Genetics does a full-sequence analysis on the four genes that encode fat sensitivity, insulin resistance, glucose balance, and physiological response to exercise. "The genes we test are those that we know wecan influence," says cofounder and CEO Kurt Johnsen. "We strive to provide our clients with tools, rather than just information." Again, you select your goal and then receive recommendations in three categories: Do, Eat, and Take (as in, supplements). In the case of finding that a client may have genes that predispose them to hold on to fat, he or she may get a prescription to switch from yoga to three 20-minute HIIT sessions a week (HIIT has been found to better mobilize fat burning than steady cardio, along with these other eight benefits).
Among the blood analytics companies, InsideTracker offers a variety of goal-based options. It will, for example, check your total cholesterol (LDL and HDL) and triglycerides using a few vials of your blood and tell you what the results mean in terms of your metabolism and ability to lose fat. "All those biomarkers optimize metabolism in a different way," Blander explains. "High cholesterol, for example, indicates you should eat less fat, fewer carbohydrates, and more fruits and vegetables. A by-product of this is that you lose weight."
Blueprint for Athletes, on the other hand, is a blood analytics company that caters to those who are more serious about their training (the company has partnered with the New York Giants) by offering options like an "endurance package." The lab tests look at endurance biomarkers and key nutrients specific to oxygen-transporting red blood cells in the body, says Maren Fragala, Ph.D., the director of athlete health and performance for the company. "Endurance capacity is largely determined by an athlete's ability to consume and utilize oxygen," Fragala explains. "Without it, your body won't be able to perform effectively." One fix that might be given: Eat more iron-rich leaner red meats and dark leafy greens, because hemoglobin (the protein in red blood cells that carries oxygen) is closely linked to your level of iron.
But there's a hitch: With blood tests (unlike genetic tests), many biomarkers in your blood, including glucose and hemoglobin, can shift quickly as a result of lifestyle modifications, so the tests may best serve your get-fit mission when they're repeated over time, allowing you to track your results and improvements. "Some biomarkers are radically affected by interventions as well as environmental changes, so we get better feedback if we do the test multiple times," Fragala notes. That said, doing it just once will give you a snapshot of your health, as well as baseline information that you can use to up your game. (If you don't want to splurge on a test, just train for your body type.)
So are they legit?
"Everyone's looking for an edge," says Rehal Bhojani, M.D., a family and sports medicine specialist at the Memorial Herman Medical Group in Sugar Land, Texas. "When there's a new test or lab value that can be used to enhance performance, society jumps on it, sometimes without proper confirmation that it is valid." Dr. Bhojani sees the value in having testing done to unearth any hindrances to your training. "If the test is one that has already been validated in the scientific literature, it can help adjust your training regimen." Companies like InsideTracker state that they issue recommendations based on the findings of peer-reviewed medical studies, which have established the links between certain biomarkers or genes and various aspects of health and fitness.
In short, read the small print. Check the companies' websites for the qualifications of the experts behind the curtain. Ask about which studies back up the recommendations you receive. And if you see any results that concern you, don't hesitate to contact your doctor to talk it out. That's also your best bet for getting a second opinion on your new regimen. (Plus, it could have a placebo effect, just like the "fat gene.")
The Fit Girl's Guide to Testing Companies
Saliva test: For everyday exercisers who want tips for reaching their ideal body composition. ($499; simplifiedgenetics.com)
Saliva test: Suited to those looking for diet and exercise plans and a linkup with a trainer. ($129 to $167; dnafit.com)
Saliva test: Geared to people with get-in-shape goals. ($229; fitnessgenes.com)
Blueprint for Athletes
Blood test: For the athlete in training who has specific performance goals. (From $200; blueprintforathletes.com)
Blood test: For those looking to increase their body's functionality with nutrition and exercise advice. ($99 to $499; insidetracker.com)