Sports Medicine
A Crucial Period
Good Pain, Bad Pain
On Your Knees
Secondary Injuries
Imaging Technology
What's Sciatica?
The Female Athlete
Putting Your Feet First
Itis Schmitis
Too Much, Too Soon
Under the Influence
Twisted
What's Goin' On?
Think Inches, Not Pounds
Preventing Vaginitis
That Painful Pull
Athlete's Heart
Exercise & Arthritis
Chilled to the Bone
Measuring Body Fat
Exercise and Your Breasts
Choosing a Sports Doctor
Lean on Me (Shoulder)
Exercise & Anemia
Exercise Abuse
Pelvis Sighting
Hand Aid
It's All in the Wrist
Back in Action
Altitude Adjustment
Tennis Elbow, Anyone?
Exercising in the Heat
Agony of the Feet
Restless Legs
Night Time Cramps
Birth Control Concerns
No Periods, No Babies?
Post Partum Prescription
Weight Loss Mystery
Undesirable Cooldown
To Brew Or Not To Brew
Fitness After Baby
Biking and Back Pain
Swimmer's Shoulder
A Hidden Athlete
Avoiding Osteoporosis
Drug Testing
Maximum Heart Rate
Headway Against Headaches
Torn Rotator Cuff
Fat Figures
SOS About PMS
Bloody Urine
Sag Story
Lackluster Leg
Bothersome Bulge
Gaining in Years
Taking It On the Shin
Aching Ankles
Hoop Help
Tender Toes
Meals For Muscle
Growing Pains
Hot Tips
High Altitude PMS
Personal Bests
Air Pollution
Ankle Blues
Heartbreak Heel
Yeast Relief



Measuring Body Fat

Continued...

Errors are caused by different states of hydration of the subject, using the wrong equations for the type of calipers, and the difficulty of finding and measuring exactly the same site on the same person at different times. Even in the best hands (someone who has tested more than 200 people) the error range is still plus or minus 2 to 5 percent.

In an attempt to reduce human error; new measuring devices have been developed and are being aggressively marketed.

Bioclectrical impedance analysis (BIA) uses an electrical current to estimate body fat. Four electrodes are placed on the skin and a current is passed between them. The impedance (opposition) to this current flow is measured; a built-in computer calculates body-fat percentage from this measurement. BIA is based on the principle that fat provides more impedance than other tissue, because it contains less water (water being a conductor of electricity).

Conditions must be tightly controlled to assure consistent results. Differences in skin temperature, blood flow, hydration and placement of electrodes will yield inconsistent results. if, for example, one day you're tested in a warm room after you've been exercising, and the next day you're tested in a cool room after you've been resting, the results will be considerably different.

The reliability of your test will also depend on the type of machine (there are currently three on the market) and which of two equations is used to calculate a percentage. The combination that's right for you is based on your body configuration, age and sex. The overall error range for BIA testing is plus or minus 3 to 3.5 percent.

Near-infrared spectrophotometry and ultrasound use infrared light or ultrasound rays to estimate bodyfat percentage. The device that emits the rays is placed on a body part, usually the arm.

Ultrasound measurements vary greatly with the amount of pressure exerted on the skin. Infrared measurements eliminate this source of error; but both methods use equations with built-in assumptions that may be inaccurate for your particular body.

How important is all this?

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Table of Contents

Foreword: Billie Jean King

Comments by Barb Harris
Editor in Chief,
Shape Magazine



General Health
Nutrition
Exercise
Common Medical Problems
Dental Health
Emergency!
Infectious Disease
Sexual Health
Emotional Well-Being
Eating Disorders
Alcohol & Other Drugs
Environmental Health
Prevention


The information in this web site is for educational purposes only and is not providing medical or professional advice. It should not be used for diagnosing or treating a health problem or disease. It is not a substitute for professional medical care. If you have or suspect you might have any health problems, you should consult a physician.


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