Monday, September 27, 2010

Body Mass Index (BMI)

What is Body Mass Index (BMI)?

The BMI assessment is a simple and cost effective screening tool for kids and adults.  BMI is calculated using one's body height and body weight ratio and determines the level of fitness.

BMI is an estimate of body fat and does not actually measure body fat tissue.  It does not account for actual tissue type as muscle has a greater density then fat.  Through BMI assessment extremely muscular individuals may measure as overweight according to their height.  This would be a problem more with adults then children. It can also predict an older individual is underweight because they have started to lose their muscle.

Why do you measure your BMI?

BMI is a good gauge to recognize your risk of diseases that can occur as a result of high body fat.  The higher your BMI, the higher your risk for certain diseases such as heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers.

It is also an effective, inexpensive method to regulate your body weight to help you reach personal goals you may set for yourself.

What is the Formula? And what does it mean?

The formula to calculate one's BMI is:

   WEIGHT (lbs) x 703 =   BMI
Height(in)(squared)


EXAMPLE:

If you have an individual who is 5'6'' and weighs 125 lbs-

125 x 703___ =    87,875  =   20.17
(66)squared           4,356


SO WHAT DOES 20.17 MEAN?

If you click the following link and view the PDF version of the BMI table:


On the BMI table, the above individual body weight:body height ratio would be considered to be in the healthy range.


Evaluation Criterion

Ok, so as a result of your BMI calculations, you may have a couple different reactions.  You may be satisfied with your results; you may be dissatisfied with your results or you may be completely shocked.  There is no need to panic!!! These numbers can be changed!! All it takes is a little moderation in your diet and a little exercise!!

The evaulation criteria are as follows:

Healthy- This result means your calculations fall right in the recommended range for your height/weight ratio. 

Overweight- This result means you have fallen a little above your recommended BMI.

Needs Improvement- This result means you have fallen a little too much out of your recommended BMI calculations.

No Need to Worry!!! All it takes is a little exercise and diet moderation. 

WHEN IS THE NEXT ASSESMENT?

Mark your calendars!!! Our next BMI assessment will be on Monday, November 22, 2010.  Be prepared!

HOW DO I IMPROVE MY BMI??

After our first assessment, you might be saying to yourself, "Well Coach Byrne how do I improve my BMI for our next assessment?"  Here are some simple guidelines you can follow:


MY BMI IS TOO LOW

Some people do experience that their BMI is too low for their height, meaning they are underweight.  If your BMI is too low for your height, you need to increase your lean muscle mass.  You should participate in a strength training program after consulting a professional.  Once again, you can consult a nutritionist to balance your diet.  Just because your BMI is low, does not mean you can go to McDonald's everyday!! You want to gain weight in a positive manner.  Building lean muscle mass will increase your overall health because lean muscle burns more fat and calories during rest.

MY BMI IS TOO HIGH

Don't panic!!  If your results of your BMI assessment were that your BMI is too high for your height, you will need to work on lowering it.  This is not a difficult task either.  First, examine your diet.  Figure out what you are eating, and how many time you are driving thru McDonald's per week.  If you make one change per week, it will help!! Every little bit will help, but be sure to consult a professional when making changes to your diet because your diet needs to be balanced even though you are trying to lose weight.  Remember what I said in class, fat is an important part of your diet and your body needs it!!!

It is important to add exercise to your routine as well.  You should choose an exercise routine that you can stick to and will fit into your schedule.  Don't make plans to go to the gym 5 times per week for 2 hours if it is not feasible with your schedule.  Make sure you choose goals that are attainable.  Starting a work out routine will not only burn fat and calories, but it will also improve your overall health as well!

MY BMI IS JUST RIGHT!!

If your BMI results came back at a healthy level, then you are doing something right!! Keep doing what you are doing, and keep exercising!!


HOW VALID IS THE BMI TEST?
The FITNESSGRAM Healthy Fitness Zone for the BMI assessment is different from the widely used CDC percentile-based charts. As described elsewhere in this document, FITNESSGRAM standards are established as "criterion-referenced standards." The standards are based on the level of fitness needed for good health, rather than comparisons of test populations.  It is an accurate measurement for children to the age of 10 as it is a comparison of height to weight ratio. 

There are limitations associated with the use of BMI for assessing weight status or body composition. The main limitation is that the BMI will yield inaccurate values for people that have a large muscle mass, but this is not a problem when it comes to children because majority of children prior to age 10 do not develop muscle mass.

IS THIS TEST RELIABLE?

I was able to control the reliability of this test by weighing and measuring everyone's heights myself.  I did not rely on students to measure themselves.  This was to be sure that the results were reliable.  Weight is a sensitive issue which students may tend to fabricate, but I was able to ensure this would not happen by measuring everyone myself. 

VIDEO EXPLANATION OF THE BMI

The video below is an explanation of what the BMI assessment consists of, what it measures, and how it is performed.





HOW DID OUR CLASS PERFORM AS A WHOLE??

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The STANDARD DEVIATION for the class was 4.031
The MEAN for the class was 25.715
The RANGE for the class was 18.9-33.0

Below is a chart that will show our class results as a whole and also how the female students compared to the male students: