Practical One - Body Composition Flashcards
What do I need to know how to measure?
BMI
Waist Circumference
Waist to hip ratio
Waist to height ratio
Bio-electrical impedance analysis
Skinfold measures
How do you measure Body Mass Index?
Mass (Kg) / Height (m) / Height (m)
What are the units for Body Mass Index?
Kg/m2
How do you carry out the procedure for Body Mass Index?
- Using a stadiometer ask pp to stand heels together with heels, buttocks and upper back touching the stadiometer.
- Keep head in Frankfort plane.
- Ask pp to breath in deeply and hold.
- Place headboard firmly down.
- Ensure heels do not leave the floor.
- Take the reading before the pp exhales.
What are the normative values for Body Mass Index?
Underweight >18.5
Normal 18.5 - 24.9
Overweight 25 - 29.9
Obesity 30+
Where do you measure waist circumference?
Distance around the narrowest part of the torso
Between xiphoid process and umbilicus (Howley 2017)
What is a higher waist circumference associated with?
A higher risk of disease
Where do you measure waist circumference from is there is no narrowest point?
Take the measurement at the 10th rib
What is the procedure for measuring waist circumference (adapted from ACSM guidelines)
Subject stood still feet together hands by sides
Relax their abdomen
Measure
Record score
What are the normative values for waist circumference?
Male >120cm
Female > 88cm
Scores equal to or above these significantly increase the risk of obesity related disease
What is the waist to hip ratio
The ratio of the circumference of the waist to the hips
Quick, easy, useful for estimating the level of abdominal obesity and disease risk
What is a higher waist to hip ratio associated with
Higher risk of obesity and higher risk of disease
What is the procedure to measure waist to hip ratio?
Using anthropometric tape measure
Record waist circumference
Then hip circumference
Use the equation to work out WHR
What is the equation to work out Wait to Hip Ratio?
WHR = waist circumference (cm) /hip circumference (cm)
What are the normative values for Wait to Hip Ratio?
Male:
Average 0.9-0.95
Excellent <0.85
Female:
Average 0.8-0.86
Excellent <0.75
A score closer to 1 means there is a greater risk of obesity and greater risk of disease
What is the waist to height ratio
It is designed to measure level of abdominal obesity and distribution of fat
Considered a more useful marker for early health risk than BMI and Waist Circumference
What is the procedure to measure Waist to height ratio?
Measure height using a stadiometer
Measure waist circumference
Use equation to calculate Waist to Height Ratio
What is the equation to measure the Waist to Height Ratio
WHtR = Waist Circumference (cm) / Height (cm)
What are the normative values for the Waist to Height Ratio?
Less than or equal to 0.5 = no risk
0.5 - 0.6 = increased risk
Greater than 0.6 = very high risk
How does Bio-Electrical Impedence Analysis work?
Low level electrical current is passed around the body (50kHz)
The level to which this current is impeded is measured by electrodes in the hand and foot
Fat is a poor conductor of electrical current. So body fat % can be estimated by the level of impedance.
Higher impedance means high levels of fat
What is the procedure for Bio-Electrical Impedance analysis? (Not what to and where to place each electrode)
Pp should empty bladder and avoid alcohol and exercise 48 pre
Weight pp, record their height, ask how physically active they are
Clean electrode sites with alcohol wipe (always right side of the body)
Lie on floor on non-conductive mat
Arms and legs are at 45 degree angle to the body
Legs not touching each other
Enter details into BIA machine
Press go, few seconds later you’re given a reading of body fat % amongst other values
Where are the black electrodes placed for Bio-Electrical Impedance Analysis?
Always above the red electrodes
For the hand - the back of the wrist where the arm meets the hand
For the foot - the surface of the ankle where the leg meets the foot in the middle
Where are the red electrodes place for Bio Electrical Impedance Analysis
Always below the black electrodes
At the hand - back of hand just behind the middle and forefinger knuckle
At the foot - between the second and third toe just behind the knuckle
What are the normative values for males for Bio-Electrical Impedance Analysis?
18 - 34 = 8-22%
35 - 55 = 10-25%
56+ = 10-25%
What are the normative values for females for Bio-Electrical Impedance Analysis?
18 - 34 = 20-35%
35 - 55 = 23-38%
56+ = 23-38%
How do skinfold measures (Skinfold thickness) actually work?
Measure the thickness of subcutaneous adipose tissue (skin and underlying fat)
What is the relationship between skinfolds and body density across a large range of body fatness levels?
It is a curvilinear relationship
What is a curvilinear relationship?
As one variable increases, the other variable also increases but only up to a certain point.
Past that point as one variable continues to increase, the other decreases
What is the procedure for skinfold measures?
Ask pp to remove clothing covering the sites
Stand in a relaxed manner
Locate skinfold sites (right hand side of the body)
Mark skin to minimise error when repeating measures
Left hand grasps skin, right hand uses callipers.
Adipose tissue is held between the thumb and index finger without any muscle
Two seconds after applying callipers note the reading
Repeat measures one after another until completed all
Then come back and take a second reading, if there is a difference of 5% or more a third should be taken after completing a second for all
Why should you not take skinfold measures after showering or exercise?
Both cause an increase in blood flow to the skin, increasing skinfold thickness
What are the normative values for males for skinfold measures (skinfold thickness)?
Poor = 150+
Below Average = 111-150
Average = 91-110
Good = 81-90
Excellent = 60-80
What are the normative values for females for skinfold measures (skinfold thickness)?
Poor = 150+
Below average = 121-150
Average = 101-120
Good = 91-100
Excellent = 70-90
How many areas for skinfold measures (skinfold thickness) do we have to know?
8
What are the 8 skinfold measures (skinfold thickness) areas we have to know?
Tricep Bicep Subscapular Supraspinale Abdominal Illiac crest Thigh Calf (Gastrocnemius)
Watch the videos for the skinfold measures (skinfold thickness)
Tricep Bicep Subscapular Supraspinale Abdominal Illiac crest Thigh Calf (gastrocnemius)
What is BMI?
An appropriate measure of assessing whether someone is overweight/underweight/healthy (in general population)
