**Medical-Fitness Technician**

**Certification Course**

Part C:

**Assessing Medical-Fitness**(LM:25-34)

**Learning Module 27-B:**

Anthropometrics

Study the Learning Module and take the Quiz.

**Calculating BMI & WHR**

**Learning Objectives:**

- Correctly determine Body Mass Index (BMI)
- Correctly calculate Waist:Height Ratio (WHR)

**1. Body Mass Index**

Body Mass Index (BMI) is a calculated value that allows direct comparison among people of differing height and weight. The

**BMI Chart**below is useful to determine a client's BMI and Healthy Weight Range without having to calculate the BMI directly.- First, find the client's Height in the left-hand column. Example: Client is 5' 8".
- Then, find the client's approximate Weight in the horizontal row of the client's height. Example: 205 pounds = 203 pounds.
- Finally, find the client's BMI at the top of the column of the client's approximate weight. Example: BMI = 31
- Note the Category of the client's BMI, but be cognizant that it may need to be adjusted by the client's WHR (below).
- As you gain experience using the chart, you will become more proficient at estimating the client's precise BMI to the first decimal. On the chart, a weight of 203 = a BMI of 31 and 210 = 32, so the client's weight of 205 would be a BMI of about 31.2.
- BMI is recorded as a number rounded to the first decimal point and without units (no inches or pounds).

If the client's Height and/or Weight is "off-the-chart" above, use the formula below to calculate BMI.

**(Wt**in pounds

**/ Ht x Ht**in inches

**) x 703 = BMI**

Install a free

**BMI Calculator App**on your smart phone. There are several excellent versions available.**2. Waist:Height Ratio**

A person's Waist-to-Height Ratio (WHtR or WHR, but not to be confused with Waist:Hip Ratio) is defined as Waist Circumference divided by Height, both measured in the same units (inches or cm). WHR is used as a predictor of obesity-related cardiovascular and other chronic diseases, because it measures the distribution of body fat. Higher values of WHR are correlated with abdominal obesity and indicate higher health risks. A "boundary" value of

**0.5**or more (one-half or more of the person's height) indicates increased risk.**Waist Circumference**(inches) .

--------------------------------------------

**= WHR**

**Height**(inches) .

- Use the calculator app on your smart phone to calculate your client's WHR.
- Record the WHR as a number rounded to the second decimal point without units. Example: 32 / 68 = 0.47

**Supplement: Percent Body Fat (%BF):**The current position of the OptiHealth Institute in regard to body measurements and the determination of weight-related health risks is to use BMI & WHR instead of %BF. The supplemental information linked below explains the rationale of our position. The supplemental information is not a required part of this course, although it is strongly recommended that you educate yourself on this sometimes controversial topic.