The Performance Life
The best thing about having the good fortune of co-authoring Core Performance books with Core Performance founder Mark Verstegen is having access to experts in human performance and cutting-edge research. (It’s the same information provided in the books and on this site, but being around it so closely keeps it in the front of my mind.) Last month I had my bodyfat measured with skinfold calipers at Athletes’ Performance in Phoenix for the fourth time since December of 2008.
Body composition is a more accurate barometer of overall fitness than scale weight. Two men or two women roughly the same height, weight, and age can have dramatically different appearances based on body composition. Simply put, body composition is the percentage of body weight composed of fat as opposed to lean mass (usually expressed in terms of a body-far percentage – 12 percent, for example, which is typical for a male team-sport athlete).
There are options when it comes to measuring body composition, ranging from the high-tech (Dual Energy X-ray Absorptiometry, also known as DEXA or DXA) to hydrostatic weighing. There’s also bioelectrical impedance (BEI), which can be as simple as stepping on an inexpensive BEI bathroom scale. The subject stands on two electrodes that send a small current through the body, measuring the impedance to this current. (For a more thorough breakdown on body comp options, see our complete guide to body composition.)
Skinfold calipers are perhaps the best combination of simplicity, portability, and accuracy. That’s assuming a trained technician does the measuring. The technician uses the calipers to pinch the subject at seven sites: chest, abdominal, thigh, tricep, subscapular, iliac, and midaxillary. The thickness of the skin folds at the seven sites, measured in millimeters, is totaled and inserted into an equation (Jackson-Pollock), along with sex, age and weight to determine the subject’s body fat percentage. “You’re separating the skin and fat tissue from muscle tissue,” says Erika Wincheski, a performance nutritionist at Athletes’ Performance. “We find skin folds to be a fairly accurate measure.”
In March of 2009, I weighed 173.8 and measured 11.48 percent body fat. By December of 2011, I weighed 161 and had dropped to 8.65 percent body fat. (Height, of course, remained unchanged at 5-foot-11.) After a year of training for triathlon, stand-up paddleboard events, and obstacle races, I finished 2012 at 155. Perhaps more importantly, I had dialed in my nutrition further. The results were encouraging, especially for a 43-year-old recreational athlete.
|Mid Ax (mm)||3.5|
|SUM 7 Site (mm)||41|
|Body Fat %||7.19%|
|Lean Body Mass (lbs)||143.85|
|Fat Mass (lbs)||11.15|
Just for comparison’s sake, Wincheski lowered my age to 25, which dropped my body fat percentage to 5 percent. Since we lose lean mass as we age, age is a key variable in the equation. So too is adequate pre- and post-workout nutrition, something I’ve focused on more during the last year.
“As you age, your body is going to lose some of its lean muscle tissue,” Wincheski said. “We want to prevent that and increased activity will help. There’s a recovery piece there as well. You want to recover your body after training, otherwise you’ll continue to break down that muscle tissue. So by allowing yourself that recovery period to refuel your glycogen stores, and giving yourself the proper amount of protein and carbohydrate, you’ll prevent that muscle tissue breakdown.”
Seven percent bodyfat is comparable to some of the world-class soccer players and sprinters who train at Athletes’ Performance, though they can be as low as 3.5 percent. Of course, I never had world-class athletic skills at their age—or any age. The 7.2 percent “speaks to how lean you’ve become,” Wincheski said. “Muscle tissue is not being broken down and that’s a challenge for all of us as we get older.”
Related: The Problem with All This ‘Overweight People Live Longer’ News [The Atlantic]
About The Author
– Pete Williams is a contributing writer for CorePerformance.com and the co-author of the Core Performance book series.
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