SHMD 2497/3/2012

Body Compositi

on

Statistics

Statistics

Health Risks Associated with Being Overweight

• Coronary heart disease• Hypertension• Hypercholesterolemia• Diabetes

Health Risks Associated with Being Overweight

There are also health risks associated with being too thin!• The body reacts to the lack of food by becoming extremely thin• developing brittle hair and nails• dry skin• constipation, diarrhea• reduced muscle mass, loss of menstrual cycle• swelling of joints• heart problems • osteoporosis• mental health issues • death

Definitions• Mass: the body’s total weight.

• Body composition: The relative percentage of muscle, fat, bone,

and other tissues that comprise the body.

• Fat mass: is made up of fat (adipose tissue).

• Percentage body fat: % of total body weight that is composed of fat.

• Lean body mass: Lean body mass is the weight of a person's body

minus the fat. This includes muscle, bones, organs, and other

nonfat tissue.

Definitions• Underfat: too little body weight comprised of fat.

• Overfat: too much of the body weight comprised of fat.

• Obese: extreme overfatness.

• Moderately Overweight: 20% over desirable body weight.

• Severely overweight: 40% over desirable body weight.

Proper uses of results:- Serve as baseline data for repeated testing.-Provide motivation for goal setting.-Provide awareness about health risks.-Estimate athlete’s optimal body weight.-Monitor changes in body composition (Athletes, children, overweight persons)

BMI

WHR

Skinfold assessment

Body Composition

Testing

BMI Re-Cap• BMI: A measure of body composition using a height-weight formula

• BMI is used to give us an idea of whether the client is obese, and the extent of their

obesity

• Formula:

– Body mass index (BMI) = weight in kilograms divided by height in meters

squares

– BMI = kg

h2

– BMI unit of measurement: kg/m2

BMI Re-Cap• BMI does not actually measure body composition

• It can be used as a quick measurement to check if an individual is

overweight, but it is inaccurate

• BMI does not distinguish between fat and muscle

• Muscle is denser, thus heavier than fat

• i.e. A person with a lot of muscle may be

inaccurately described as obese

• Hip-to-waist ratio (HWR) is taken as an indicator of the health risks

associated with obesity, and in particular the risk of coronary heart diseaseRegional Fat Deposition

• Abdominal body fat poses greater health risks than fat stored in other areas

• Males store more fat centrally and have increased health risks associated with body fatness

Higher health risk Lower health risk

Hip-To-Waist Ratio Re-Cap

Hip-To-Waist Ratio Re-Cap• Hip-to-waist ratio = waist measurement in centimetres divided

by hip measurement in centimetres • HWR = waist (cm)

hip (cm)

Gender HWR Classification

Males > 1.0 High risk

0.90 – 0.99 Moderate risk

< 0.90 Low risk

Females >0.85 High risk

0.80 – 0.85 Moderate risk

< 0.80 Low risk

Levels of Body Fatness Men Women

Essential fat 5% 10%Borderline 6-9% 11-16%Good fitness - health 10-20% 17-28%Marginal fitness 21-25% 29-35%Overfatness > 25% > 35%

• Essential fat: the minimum amount of fat in the body necessary to maintain healthy living

• Nonessential fat: extra fat, or fat reserves stored in the body.

Body Composition Assessment TechniquesSkinfold Technique

• Layers of subcutaneous fat are measured at different sites of body

to estimate total body fat levels.

• Advantages• Fairly accurate• Easy to perform• Inexpensive

• Disadvantages• Human error

4 SiteTricepsBiceps

SubscapularSuprailiac

Common Skinfold Sites

7 SiteChestAxilla

TricepsSubscapular

AbdomenSupraillium

Thigh

Skinfold TechniqueArea DescriptionTriceps With the clients arm hanging loosely, a vertical fold is

raised at the back of the arm, midway between the shoulder and elbow.

Biceps A vertical fold is raised at the front of the arm, opposite the triceps site. This should be inline with the fold of the elbow.

Subscapular This is taken 2 cm below the lowest point of the shoulder blade (inferior angle), and is taken at a 45° angle.

Suprailiac This is taken just above the iliac crest (hip bone), directly below the front of the shoulder.

Pg 158

Skinfold TechniquePg 158

• The skinfold assessment test is carried out using a skinfold

caliper.

• Pre-measurement Instructions:

• Measurements should not be taken after training or

competition, sauna, swimming or showering.

• Exercise, warm water and heat can produce dehydration or

increased blood flow = inaccurate results.

Skinfold TechniquePg 158

1. Take the measurements on the left hand side of the body.2. Mark up the client accurately.3. Using your forefinger and thumb, pinch the skin 1 cm on either

side of the mark.4. Pull the fat away from the muscle.5. Place the caliper halfway between the top and bottom of the

skinfold.6. Allow the caliper to settle for one or two seconds.7. Take the reading and wait 15 seconds before repeating for

accuracy.8. Add up the total of the four measurements.9. Calculate body fat % using the table.

MalesSum of SF

Body Fat %

FemalesSum of SF

Body Fat %

14 9.416 11.218 12.7

20 7.1 20 14.122 9.2 22 15.424 10.2 24 18.526 11.2 26 17.628 12.1 28 17.630 12.9 30 19.535 14.7 35 21.640 18.3 40 23.445 17.7 45 2550 19.0 50 28.555 20.2 55 27.560 21.2 60 29.165 22.2 65 30.2

MalesSum of SF

Body Fat %

FemalesSum of SF

Body Fat %

70 23.2 70 31.275 24.0 75 32.280 24.8 80 33.185 25.6 85 34.090 28.3 90 34.895 27.0 95 35.6

100 27.6 100 38.3110 27.8 110 37.7120 29.9 120 39.0130 31.0 130 40.2140 31.9 140 41.3150 32.8 150 42.3160 33.6 160 43.2170 34.4 170 44.6180 35.2 180 45

Pg 159

Body Fat & Sports Performance

Jockey:

Average weight: 50.44kg

Average height: 1.57m

BMI: 20.46

Sumo Wrestler:

Average weight: 219kg

Average height: 1.91m

BMI: 60.03

Body Fat & Sports Performance• Excess body fat can negatively influence many types of sport

performance requiring jumping and running.

• High ratios of fat free mass to fat mass are generally positively related

to sport.

• Athletes are leaner than sedentary individuals – regardless of gender.

• Extremely low fat mass in women can result in health problems

(Refer: “too thin”).

Body Fat & Sports PerformanceSwimmer

Balletdancer

Rugby player

Volleyballplayer

Body builder

Sumo Wrestler

Questions1. Define:

a. Body composition. 3b. Lean body mass. 3

2. What do the following abbreviations stand for:a. BMI 2b. WHR 2

3. What is the unit of measurement for BMI? 14. What are the risks associated with being overweight? 45. List 8 risks associated with being underweight. 86. What is BMI; and what is it used for? 47. What is the calculation used for BMI? 28. A man weighs 76kg and is 1.71m tall. Calculate his BMI. 29. In tabular form, write down the categories and range of BMI. 1210. What are the limitations of BMI? 3

11. Differentiate between ‘overfat’ and ‘obese’. 212. What is the WHR used for? 213. Differentiate between the ‘apple’ and ‘pear’ body shape, also explain which one

is of greater risk and why. 614. Which shape is generally associated with males, and which shape is generally

associated with females? 215. What is the formula for measuring WHR? 216. If a woman has a waist measurement of 72cm, and a hip measurement of

110cm, calculate her WHR. 217. How would BMI differ between a race horse jockey and a sumo wrestler, and

why? 618. How does the body composition of a ballet dancer differ from that of a body

builder? 419. What are the results of body composition tests used for? 5

Questions

20. Differentiate between ‘essential fat’ and ‘non-essential fat’. 421. What percentage of body fat is ‘essential’ for women, and what percentage is

essential for men? Why do they differ? 422. Briefly explain how the skinfold technique is used to measure body fat. 323. What are the advantages and disadvantages of the skinfold technique? 424. List the skinfold sites used for the 4 site technique, also describe how you would

measure at each site. 425. List the skinfold sites used for the 7 site technique. 726. When should skinfold measurements not be taken and why? 527. What is the general procedure for measuring skinfolds? 9

Questions