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Health & Fitness Tools

Tool #1 - Body Mass Index Chart

The Body Mass Index (BMI) Chart provides you with a very simple way to assess your current body composition, which is one of the four elements of fitness (for a more detailed description, review the May 2006 issue of my Fitness Corner newsletter, What Does it Mean to be Fit).  BMI is a relative measure of body height to body weight.  It can help you understand the extent to which you are at a "healthy weight".    You can use the Body Mass Index Chart by finding your height in inches along the vertical axis and moving across this row to find your weight in pounds.  Your BMI can be found at the top of the chart in the column that contains your weight (or the number closest to your weight).  You will fall into one of three categories, Healthy Weight, Overweight or Obese.  It is very important to remember that BMI is far from perfect and can be inaccurate based on individual factors such as muscle mass, bone structure, age, gender, ethnicity and height extremes (very short or very tall).  For example, a heavily muscled individual with little body fat might fall into the Overweight or Obese category.  For this reason, whenever possible BMI should be used in conjunction with other body composition measures such as circumference measures and body-fat estimates. 

Tool #2 - Body Fat Rating Scale

In addition to the Body Mass Index (BMI) approach described above, body-fat percentage is an excellent way to assess your current body composition.  In fact, by definition, body composition is the relative percentage of body weight that consists of body fat and fat free mass (everything other than fat such as muscles, organs, blood, bones & water).  Therefore, the most effective way to evaluate your body composition is to determine your body-fat percentage.  Unfortunately, unlike BMI, this is not easily done.  Generally speaking, there are four ways to assess body-fat percentage: hydrostatic weighing, bioelectrical impedance, skinfold measurements and circumference measurements.  Each is described below.  Once you have identified your body-fat percentage, you can use the Body Fat Rating Scale to evaluate your body composition (e.g., obese, fit or athletic).

1. Hydrostatic Weighing - Also called 'underwater weighing', it is undoubtedly the "gold standard" of body composition assessment.  The process involves submerging the person in a tank of water and is based on the idea that fat free mass is heavier than water and sinks while fat is lighter than water and floats.  By comparing your land weight with your water weight, the tester can accurately determine your body fat as a percentage of your total weight.  While hydrostatic weighing is the most accurate way to determine body-fat percentage, it is also the least convenient and most expensive.

2. Bioelectrical Impedance - This technique is based on the idea that the conductivity of an electrical current is greater through fat free mass than through body fat.  By measuring the resistance to the current as it passes through the body (don't worry, you won't feel anything!), the machine estimates body-fat percentage to a reasonably accurate degree (although it is less accurate than hydrostatic weighing).

3. Skinfold Measurements - This is the easiest and least expensive way to determine body-fat percentage.  You will need someone to assist you (an experienced Certified Personal Trainer is best).  Using a pair of Skinfold calipers, the trainer will take measurements at specific body locations (chest, abdomen and thigh for men; tricep, abdomen and thigh for women).  The trainer can then estimate your body-fat percentage based on the sum of the 3 skinfold measurements. 

4. Circumference Measures - In actuality, a basic circumference measure does not yield a body-fat percentage.  However, like BMI, it is a very simple way of determining health risk.  First, determine your waist circumference at the navel.  Women with a waist measurement over 35 inches and men with a waist over 40 inches are deemed high risk for disease.  Another, more accurate circumference measure is waist-to-hip ratio (hip measurement is taken at the point of greatest circumference).  A woman whose ratio is greater than 80% (waist size is more than 80% the size of the hips) is deemed high risk.  For men, 95% (waist size is more than 95% the size of the hips) is considered high risk for disease.

Tool #3 - Glycemic Index

The Glycemic Index (GI) was introduced in the 1980's as a way of measuring a carbohydrate's effect on blood sugar.  Specifically, high glycemic foods trigger a large spike in blood sugar levels.  This, in turn, causes the body to release insulin to remove the excess sugar.  The problem is that large amounts of insulin can prevent your body from burning fat, and cause more of your food to be stored as body fat.  To avoid this problem, you should primarily consume low glycemic foods (however, before, during and after exercise, high glycemic foods are better because they quickly replenish the body's fuel stores).  Low glycemic foods provide a variety of health benefits including:

Download the Glycemic Index to identify the glycemic value of a variety of common foods.  The foods are rated in comparison to glucose, which is given a rating of 100.  The lower the number, the slower the carbohydrate (i.e., low increase in blood sugar, low release of insulin).  The higher the number, the faster the carbohydrate (i.e., high increase in blood sugar, high release of insulin).  You can use the following scale to evaluate foods:

Copyright © 2005  Holmes Fitness Coaching, LLC
Last modified: July 21, 2010