Body Composition Testing

While two-thirds of the countries population are suffering from obesity, most of our clients who come to us are more concerned about their physical appearance. While our primary concern is the improvement of health we cannot ignore the aesthetic issues. To address both issues, we need to first determine the balance of dense to adipose tissue. That is we need determine how much of the body is made up of muscle and bone (lean metabolic tissue), how much is fat (adipose tissue).

Weight is simply the sum of both adipose and lean tissue which makes the scale a poor indicator of the ratio between them. So then why do we gain and lose weight during each bout of exercise and throughout the day? Easy, lets say you drink a bottle of water before a 5K run. Your weight is 150 pounds when the race starts and 148 pounds when you cross the finish line. The most likely reason for this is the obvious, you lost a certain amount of the weight from sweat. Yes, that is water weight and not necessarily adipose. Now to add to the complexity, your 5k will burn off some adipose tissue and possibly add lean tissue. The result would be weight loss due to metabolic burn and dehydration and weight gain due to hydration and hypertrophy of the lean tissue. The amount of each of these will vary depending on various factors like intensity, duration, and type of workout. The result is a weight scale that is in a continued state of flux which is a poor indication of the ratio between adipose and lean tissue. True Body Composition is measured more accurately through tests such as Hydrostatic Underwater weighing, Skin Fold or Body Mass Index.

Body Mass Index, also known as BMI, as defined by the Center for Disease Control “is a number calculated from a person’s weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.” This is misleading as there can be false readings from a BMI test. Since the test is determined by height and weight, they are poor indicator of the ratio of adipose verses lean tissue. Take a pro-athlete who is 6 feet tall and weighs 230 pounds. By the CDC’s calculations this athlete’s result is “31.2, indicating your weight is in the Obese category:” By these results, a fit athlete would be obese which would be less than true. The amount of lean tissue on this leads way to the false positive as muscle is more dense and therefore weighs more than fat. So then why does the CDC offer the BMI test? Simply put, there is a high correlation of the these numbers with Cardiovascular Disease, Diabetes, Athlerosclarosis, Arteriosclarosis, usually leading to death.

HydroStatic Testing (Underwater Weighing) is by far the most accurate test available. This test submerges the test subject in a measured pool of water. Because adipose tissue floats in water and is lighter than dense tissue, a person with a larger percentage of fat free mass will weigh more in the water. Because of the +/- 1.5% error rate, this test is considered by many to be the gold standard in body composition testing. Availability of facilities and complexity of testing modality make this test more expensive and therefore less practical for our purposes. Plethysmography is a variation on the Hydrostatic Testing where water displacement is substituted by air displacement.

Source: American College of Sports Medicine Guidelines for Exercise Testing and Prescription 6th edition and Georgia State University.

Skinfold Test, measures the amount of adipose tissue given beneath a pinched area of skin. This fold is typically taken in 3 to 7 different locations on the body and on line with the body’s natural grain of fat. The measurement of the fold is then taken with a skinfold caliper and recorded. The idea is that 50% of the body’s fat is subcutaneous which will correlate with the total body adipose composition. When compared to the results of the Hydrostatic Test, the results of an accurate skinfold will compare closely. with only a ±3% error deviation and the price of a caliper, this test is the most trusted, tried and true approach of finding the amount of adipose tissue in the body. This is therefore our preferred method of pre-exercise body composition testing.

Once we have determined your percentage of body fat and compared it to the appropriate composition chart, we will have a ruler on which to gauge your current health status, and you progress as you continue your training. We will test often to ensure your needs and goals are being met. While your weight may fluctuate and plateau, you will be able to obtain more information about your progress through body composition testing. To have your body composition taken, contact Carolina Gold Fitness and schedule your appointment today!