Taking Girth Measurements
The most common girth measurements are taken around the midsection (waist and hip) and used to determine fat gain/loss and/or predict the risk for developing heart disease. The science behind these girth measurements is based on the fact that fat tends to accumulate around the midsection. Consequently, if your circumference measurements increase, you are increasing your body fat. In other words, you can now correlate "centimetres gained" to fat kilograms gained and “centimetres lost" to fat lost. There is also a greater risk of developing heart disease when fat accumulates higher up on the body i.e. around the waist as opposed to the hips).
However, girth measurements (as a prediction of body fat) are best suited to a certain population. This type of test is most successful when used on persons who have average or above average body fat percentages. This is due to the fact that girth measurements tend to increase significantly when individuals are already quite fat and do not decrease significantly when the individual is already quite lean. The calculations used to predict % body fat from girth measurements can be done using an equation and a hand held calculator.
Advantages: It is relatively accurate and very reliable when performed on populations who are average to above average body fat. The calculations can easily be performed.
Disadvantages: It does not work well on lean individuals and it lacks high tech appeal. Measuring girths can be a fairly embarrassing form of testing for some clients.
It is also possible to use girths without estimating body fat percentages. Girths can be used purely as a base measure so changes can be seen during retesting. If a client is not interested in knowing their body fat percentage but wants to see that their waist is getting smaller this can be a fast, inexpensive and reliable measure.
As a general risk factor there are girth measurements that are used as a guideline to show an increased risk of heart disease.
- Waist girth greater than 102 cm (men) and greater than 88 cm (women)
- Waist to hip ratio greater than 0.95 (men) and greater than 0.86 (women)
Waist to Hip Ratio
Aim : the purpose of this test is to determine the ratio of waist girth to the hip girth, as this has been shown to be related to the risk of coronary heart disease.
Equipment : tape measure
Description / procedure:
A simple calculation of the measurements of the waist girth divided by the hip girth.
The waist measurement is taken at the visually narrowest waist level 
of the client, or if this is not apparent, at the mid point between their lowest rib and the top of their hip bone (illiac crest).
When recording, you need to make sure the tape is not too tight or too loose, is lying flat on the skin, and is horizontal.
It’s best to have your client look straight ahead and breathe normally. Take the narrowest measurement on an inhalation if there seems to be a large change during breathing.
The hip girth measurement is taken over minimal clothing, at the level of the greatest protrusion of the clients gluteal (buttock) muscles. The client stands erect with their weight evenly distributed on both feet and legs slightly parted, making sure that they do not tense their gluteal muscles.
When recording, you need to make sure the tape is not too tight or too loose, is lying flat and is horizontal. It may help to have the client stand on a box to make the measurement easier.
Scoring: The table below gives general guidelines for the results of the waist to hip ratio. You can use any units for the measurements (e.g. cm or inches), as it is only the ratio that is important. As a general interpretation the higher the ratio, the higher the risk of developing or suffering from coronary heart disease.
|
|
Excellent |
Good |
Average |
High |
Very High |
|
Male |
<0.85 |
0.85-0.90 |
0.90-0.95 |
0.95-1.00 |
>1.00 |
|
Female |
<0.75 |
0.75-0.80 |
0.80-0.85 |
0.85-0.90 |
>0.90 |
Other Common Girth Measurements
As previously indicated girth measurements can be used simply to show change in an individual clients size or body dimensions over time. So for clients wanting to lose size around their waists then the waist girth will show whether or not this is happening over time. Conversely some clients may wish to see changes in muscle size over time to determine if their hypertrophy oriented training is working or not. As well as the waist and hip girths, measurements to show change in the size of the chest, upper arm and upper thigh are common.
Chest
This girth measurement is used to show change in size over time in the chest and upper back region.
The measurement is taken by asking the client to initially raise their arms to the side up to shoulder level. With their arms raised the tape measure is placed around their upper torso under their arm pits. The client is then asked to lower their arms to the side.
The chest girth is taken horizontally as shown here when the client has exhaled (breathed out).
Upper Arm
This girth measurement is used to show change in the size of the upper arm over time.
The client is asked to roll their sleeve up, and raise their arm and bend their elbow to 90° as shown here.
A vertical measurement is taken at the point in the upper arm that looks largest when viewed from the front. Normally this measurement would be taken with the arm relaxed; however some clients like to ‘flex’ their arms for this measurement. If they do and you choose to take the measurement with the arm flexed you must make a note of this and ensure that their arm is also flexed in any subsequent measurements.
Thigh
The thigh girth measurement is used to show change in the size of the upper thigh over time.
Like the upper arm measurement the site is located visually by looking for the largest visual point in the upper thigh when viewed from the front. As this is relatively high on the leg it may require the client to roll their shorts up so you can identify the correct mark.
The measuring tape will not be quite horizontal – it should be at a 90° angle to the line of the femur/thigh as shown here.
