Methods of Assessing Body Composition

Assessment of body composition provides additional information beyond the basic measurement of height & weight This is essential for both the athlete and the Sport therapist

“The ratio of lean body mass (structural & functional elements in cells, body water, muscle, bone, heart, liver, kidneys etc.) to body fat (essential & storage) mass”
Heywood (2001)

You inherit your body type from your parents. Some people are born with tendency to be lean, muscular, or fat.
People who do regular physical activity typically have a larger percentage of lean body
weight.

As you grow older and the hormone levels in the body begin to change.
During the teen years, female hormones cause girls to develop more % body fat than boys.
Because of male hormones, teenage boys have greater muscle development than girls.

Children who are too fat develop extra fat cells that make it more difficult to control fatness levels later in life.
Keeping % body fat levels within the good fitness zone during childhood and teen years will help keep body fat levels in check throughout life.

“The mass of the body (bones, organs & muscles) minus the mass of body fat” Some body fat is necessary for functioning of the body (3% for men, 11% for women) Optimal values range between 5-8% for men and 12-14% for women
Any values higher than that are a sign of excess stored fat

Researchers
Physicians
Coaches
Health professionals

2-compartment model
Measures fat mass and fat-free mass

Hydrostatic weighing Air displacement Skinfold thickness Bioelectrical impedance BMI Hip to waist ratio

Valid, reliable & widely used
A person’s “regular” weight is compared with their underwater weight Hydrostatic weighing provides an estimate of total body volumeBody density is then calculated, & converted into % body fat

Volume is determined by air displacement
This technique was developed in the early 1900s and was used in research laboratories During the 1990s, a commercial model became available and is now widely used

Known as the Bod Pod Individual sits inside small chamber Computerised pressure sensors determine the amount of air displaced by the person Body volume is calculated by subtracting the air volume with the person inside the chamber from the volume of the empty chamber (air in the lungs is taken into consideration) Body density and percent body fat are then calculated More Manageable to administer than underwater weighing Test lasts for approximately 5 minutes

Frequently used by research and medical facilities Originally developed to measure bone density and to assess the risk of osteoporosis
Procedure is simple; takes only 15 minutes to administer
Uses low-dose beams of X-ray energy Measures fat mass %, fat distribution pattern, soft tissue mass and bone density

Simple to administer, but accuracy is questionable Sensors are applied to the skin and a weak electrical current is run through the body to estimate body fat, lean body mass, and body water Based on the principle that fatty tissue is a less-efficient conductor of an electrical current
The easier the conductance, the leaner the individual
Body weight scales with special sensors on the surface may also be used to perform this procedure

Takes into account a persons weight & height Formula –Weight (kg) divided by height in meters squared –BMI=kg/m2 lE.g. lHeight = 1.82m. lWeight = 70.5kg –1.82 x 1.82 = 3.3124 l70.5/3.3124 lBMI = 21.3