Phone (757)639-3153
E-mail: [email protected]
The Importance of Body Composition and % Body Fat
The measurement of % body fat is a better indicator of general health and fitness
levels than weight alone. By monitoring % body fat and weight regularly, there are many
things a person can learn about their fitness and any changes in fitness as time progresses
that cannot be learned by simply weighing with a scale. The monitoring of % body fat
will determine changes in muscle tissue over time. By knowing % body fat, the % of
muscle, bone, organs, etc. can also be determined. For example, if a person has 20% body
fat and weighs 135 pounds, then 27 pounds of this is fat. The other 80%, or 108 pounds,
is considered lean mass. Of this lean mass, the component that can change the most is
muscle tissue. Therefore, if a person monitors their change in %body fat and weight they
can also determine their change in muscle tissue. Muscle tissue can increase or decrease
depending on a persons diet, activities, exercise, and lifestyle.
There are several methods in use today to measure % body fat. At Dynamic
Health Services, we use Skinfold Calipers which are accurate and easy to use. Research
has indicated that the standard error for estimating % body fat when using the underwater
weighing technique is 2.7% and that generalized equations using skinfolds add only
about one percent to this measurement error. The procedure is quick and painless and
involves taking skinfold measurements at three sites to determine % body fat. This
technique relies on the observation that, within any population, a certain fraction of the
total body fat lies just under the skin (subcutaneous fat). The % body fat obtained by
skinfold calipers includes total body fat, not just that under the skin. A certain amount of
fat is necessary for health and body functioning, sometimes referred to as essential fat.
Once the skinfold measurements are taken, the values are used in generalized equations
developed for predicting body fat in men and women by Jackson and Pollock. These
equations include the sum of skin folds, the sex of the individual and age, thus reducing
the variability associated with age and sex.
Not all people have the same ideal body fat. It varies with age and sex, and one
person may be better at a higher or lower % body fat than another person of the same age
and sex. The following are some general guidelines and ranges that are applicable to the
vast majority of individuals. For men up to age 30, 9 to 15% is good. From age 30 to 50,
11 to 17 % is a good range and from age 50 and up, 12-19%. For women, the range up to
age 30 is 14-21%, from 30-50 it is 15-23%, and from 50 and up, it is 16-25%. It should
be noted that the ranges just given are not the averages for the U.S. population but the
desirable ranges. The actual averages for the population as a whole are much higher
because of the large number of people above the desirable ranges.
Lastly, the desirable body fat of athletes can vary depending on the sport. For
example, swimmers seem to perform better at a higher % body fat than runners. A high
lean body weight allows the body to accomplish work efficiently and expend more
Body Composition & Body Fat
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Phone (757)639-3153
E-mail: [email protected]
calories even at rest. We will help you determine your ideal % body fat to optimize your
performance for your particular sport. The chart below indicates % body fat levels for
various sports.
PERCENT BODY FAT CLASSIFICATIONS
Classification
Male
Female
Lean
Optimal
Slightly overfat
Fat
Obese
Long Distance Runners
Body builders
Swimmers
Triathletes
Cyclists
<8%
8-15%
16-29%
21-24%
>25%
4-9%
6-10%
5-11%
5-12%
5-15%
<13%
13-20%
21-25%
26-32%
>32%
6-15%
10-17%
14-24%
10-15%
15-20%
Source: Adapted from: Lohman TG. The Use of Skinfold to Estimate Body Fatness in
Children and Youth. JOPERD; November, 1987, pp. 8-102; Fleck, SJ, Body Composition
of Elite American Athletes; Am J Sports Med 11:398, 1983; Wilmore JH.
Body Composition & Body Fat
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Phone (757)639-3153 Fax (757)493-2909
E-mail: [email protected]
DATE: 1/1/01
NAME:Sample Female Triathlete with goal of 17% body fat
AGE:32 SEX:
VITALS
HR
BP
RESP.
F
REST
47
MAX
186
RECOVERY
COMMENTS
67
recovery post 2 min. rest interval
WEIGHT:142 pounds
HEIGHT: 5’5”
% BODY FAT : 26%
BODY FAT WT. (body wt. X % body fat):37 pounds
LEAN BODY WT. (body wt. - fat wt.):105 pounds
IDEAL BODY WT. {Lean body wt. / (100%-desired fat %)}:127 pounds
GIRTH MEASUREMENTS:
Abdomen:
_____
Arm:
_____
Forearm:
_____
Waist: _____
Hips: _____
Thigh: _____
Calf: _____
Other: _____
FLEXIBILITY:
Tight right hamstring and IT band with history of chronic injury affecting training and
racing over last year
.
STRENGTH:
Weak hip flexors bilaterally. Weak abdominals.
OTHER:
Goal to lose approximately 1 pound/week to reach goal competition weight of 127
pounds. Stretch IT band and hamstrings daily. Perform hip flexor strengthening exercises
and core strenthening exercises 3X/week.
Body Composition & Body Fat
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