Body-fat testing also can tell you if you have too littlefat. Maybe you can
never be too rich, but you definitely can be too thin. For women, super-low
body fat — below about 16 percent — may lead to problems such as irregular
menstrual periods, permanent bone loss, and a high rate of bone fractures.Keep in mind that every body-fat testing method has room for error. At a
recent fitness convention, Suzanne had her body fat measured by two different
methods — and appeared to have gained 11 percent body fat in a matter of
15 minutes. You may even get wildly different readings using the same test,
depending on the skill of the tester or the condition of the equipment.The only way to measure body fat with complete accuracy is to burn yourself
up and take a carbon count of the ashes. Because that technique doesn’t
draw too many volunteers, scientists have developed a number of other
methods. Here’s a look at the ones you’re most likely to come across.Pinching an inch ..................................................................................
The most common body-fat test uses the skinfold caliper,a gizmo that resem-
bles a stun gun with salad tongs attached (see Figure 2-1). When your tester
fires, the tongs pinch your skin, pulling your fat away from your muscles and
bones. (You feel moderate discomfort, like when your great aunt pinches
your cheek on the holidays.) Typically, the tester pinches three to seven dif-
ferent sites on your body, such as your abdomen, the back of your arm, and
the back of your shoulder. The thickness of each pinch is plugged into a for-
mula to determine your body-fat percentage. Your tester should pinch each
site two or three times to verify the measurement.Many things can go wrong with a caliper test. The tester may not pinch
exactly the right spot, or he may not pull all the fat away from the bone. Or
he may pinch too hard and accidentally yank some of your muscle. Also,
research suggests that certain formulas are more accurate for certain ethnic
groups, age ranges, and fitness levels.Experts give this test a margin of error of four points, meaning your actual
body-fat percentage could be four points higher or lower than it actually is.
Be sure to get tested before your workout. When you exercise, blood travels
to your skin to cool you down. This can cause your skin to swell, and you
may test fatter than you really are. Plus, calipers can slip if your skin is wet
from sweat.If you want to try this method on your own, you can purchase calipers such
as Accu-Measure (available for about $20 through Collage Video, a company
you can visit at http://www.collagevideo.com and that’s described in Chapter 19).
These calipers come with a decent booklet that explains how to test yourself
and interpret the results. For better accuracy, you may want to have a friend
perform the test on you.20 Part I: Getting Your Butt off the Couch