1. Sports Medicine
Body Composition

2. Objectives Define terminology related to body composition
Determine factors influencing body fat
Identify ideal levels of body fat
Explore different methods of calculating body composition

3. Terminology:
Body composition – the makeup of the body tissues, including muscle, bone, fat and other tissues
Skinfold measurement - layers of fat under the skin that are measured to estimate body fat
Skin caliper - a device used to measure the amount of fat beneath the skin
Percent body fat – the amount of fat in a person, expressed as a percentage of total weight

4. Body Composition Typical person
Lean body tissue = 75 to 85 %
Includes muscle, bone, skin, organs (heart, liver, kidneys, lungs, etc.)
Fat = 15 to 25 %
A low percentage of body fat is desirable; however, some body fat is essential
Insulates – helps body adapt to heat or cold
Shock absorption – protects organs/bones from injury
Source of stored energy
Helps body use vitamins effectively

5. Factors Influencing Body Fat
Heredity
Metabolism
Aging
Amount of body fat when 2 years old
Diet
Physical Activity

6. Ideal Levels of Body Fat
Essential body fat: minimum amount of body fat to avoid health problems
Teenage girls: Between 11 and 25 percent
Obese = 35+ percent
Teenage boys: Between 6 and 20 percent
Obese = 30+ percent

7. Health Risks of Being Obese
High blood pressure
High blood cholesterol
Coronary heart disease
Stroke
Diabetes
Some types of cancer (endometrial, breast, prostate & colon)
Sleep apnea & breathing problems

8. Health Risks of Being Too Skinny
Eating disorders
Anoreixa
Bulimia
Abnormal menstruation in females
Loss of bone density
Higher incidence of injuries

9. Methods of Assessing Body Fat
Hydrostatic Weighing
BodPod
Skinfold Measurements
Body Measurements
Body Mass Index
Height-Weight Charts
Waist-to-Hip Ratio

10. Hydrostatic Weighing
Based on the fact that lean mass (bone, muscle, connective tissue) sinks while body fat floats
Weight is taken on land
Lung capacity is also measured to account for air in the lungs
Person is immersed in a tank of water & then weighed
A formula applied to underwater weight & lung capacity to determine body fat
+ very accurate
- requires time, money and expertise

11. Bod Pod A machine that measures weight (mass)
Uses air to measure volume (change in pressure)
Calculates density (mass/volume)
Takes into account the air in the lungs
+ very accurate
- limited availability

12. Skinfold Measurements
Caliper is used to measure skinfolds at certain sites
Females: triceps + hips + thigh
Males: chest + abdomen + thigh
Amount of body fat is determined using age and sum of skinfold measurements
+ easy
- less accurate

13. Body Measurements
Body measurements are used to estimate a person’s percentage of body fat
Females = height & hip
Males = weight & waist
Using a chart, line up the body measurements in the two side columns and determine the percent body fat value in the middle column

14. Body Mass Index (BMI) Indicator of body composition
Take the following measurements:
Height: measured in inches, without shoes
Weight: measure in pounds, without shoes and minimal clothing
Check chart to find BMI rating
Not very accurate

15. Height / Weight Charts Method to estimate percent body fat
Comparison between a person’s height and weight
Obtain the measurements as follows:
Weigh the person on an accurate scale with shoes removed and minimal clothing
Measure the person without shoes
Then compare the two measurements
The ideal ratio is 2:1 or greater

16. Waist-to-Hip Ratio Method to estimate percentage of body fat
Comparison between the circumference of a person’s waist and a person’s hips
Waist circumference: measure the person’s waist at the level of the navel
Hip circumference: measure the person’s hips at the widest point
Using a chart, line up the body measurements in the two side columns and determine the percent fat value in the middle column