This error factor may be increased dramatically due to the skill or lack of it of the technician taking the measurements. The following sections will focus on three body fat measurement techniques that are often accessible to fitness professionals: hydrostatic weighing, bioelectrical impedance, and skinfolds.
Hydrostatic Weighing Hydrostatic weighing is a valid, reliable and widely used technique for assessing body composition.
It has been labeled the "Gold Standard" or criterion measure of body composition analysis. It is based on Archimedes' principle. This principle states that an object immersed in a fluid loses an amount of weight equivalent to the weight of the fluid which is displaced by the object's volume. This principle is applied to estimate the body volume and body density of individuals. Since fat has a lower density than muscle or bone, fatter individuals will have a lower total body density than leaner individuals.
As the person is being submerged, the air in the lungs must be exhaled completely. The air remaining in the small pockets of the lungs following a maximal expiration is referred to as the residual lung volume. The residual lung volume may be determined using a number of laboratory techniques or it is often estimated using age, height, and gender-specific equations. Once your body weight, the underwater weight, and the residual lung volume are known, total body density may be calculated.
From the total body density, the percent body fat can be estimated using the appropriate age-gender equation. One limitation of hydrostatic weighing is that it is based on the two- component model fat and fat-free mass which assumes when calculating total body density that the relative amounts and densities of bone, muscle, and water comprising the fat-free mass are essentially the same for all individuals, regardless of age, gender, race or fitness level.
It is now known that this is not the case. For instance, the fat-free body density of young Black men is greater than that of white men. Because of this, the lean body mass is overestimated and the body fat is underestimated for many Blacks. Also, after age 45 to 50, substantial changes in bone density, especially in women, invalidate the use of an assumed constant value for fat-free body density when converting total body density to percentage of body fat.
This is why age and gender specific equations need to be used for estimating body fat. As researchers learn more about age-related changes in bone mineral, hydrostatic weighing will eventually provide a more accurate prediction of body fat for older men and women. Bioelectrical impedance analysis BIA is based on the fact that the body contains intracellular and extracellular fluids capable of electrical conduction.
A non-detectable, safe, low-level current flows through these intracellular and extracellular fluids. Since your fat-free body weight contains much of your body's water and electrolytes, it is a better conductor of the electrical current than the fat, which contains very little water.
So this technique is essentially an index of total body water, from which fat-free mass is estimated. The popularity of the BIA method has grown significantly over the last few years because it is painless, quick, and easy to administer the test. To take the test, you lie on a testing table or floor and electrodes are attached to your hands and feet.
You do not feel a thing as the current passes through your body. Average time for administering this test is about 10 minutes. No eating or drinking within 4 hours of the test 2.
No exercise within 12 hours of the test 3. Urinate within 30 minutes of the test 4. No alcohol consumption within 48 hours of the test 5.
There is a tendency for BIA to overestimate percent body fat in very lean clients and underestimate body fat in obese clients. All in all, if the guidelines for testing are followed, the BIA method is a satisfactory method for assessing body composition of most people. Skinfold Method The skinfold method of measuring body fat is a practical, economical, and administratively feasible field technique for body composition analysis.
It involves measuring the skinfold subcutaneous fat thickness at specific sites of the body. Most equations use the sum of at least three skinfolds to estimate body density from which body fat may be calculated. Skinfold measurement does not require expensive equipment and it can be routinely incorporated into many health promotion settings.
Skinfold technicians can be trained rather easily, but must practice on at least clients before the skinfold technique is mastered. When using the skinfold method, it is assumed that the distribution of subcutaneous fat and internal fat is similar for all individuals. This assumption is not fully supported. It is now known that older subjects of the same body density and gender have proportionately less subcutaneous fat than their younger counterparts. There is considerable biological variation in the distribution of subcutaneous, intermuscular, intramuscular, and internal organ fat due to age, gender, and degree of fatness Heyward, Accuracy of Skinfold Measurements The accuracy of the skinfold method is dependent on the technician's skill as well as the type of caliper and the skinfold prediction equation used.
Reasonably priced plastic calipers have a less precise measuring scale, and often provide variable pressure and a smaller range of measurement. Despite this, a number of researchers have reported only small differences between skinfolds measured with high quality calipers and plastic calipers for highly skilled technicians refer to Guide to Skinfold Caliper for more information on where to purchase calipers.
However, plastic calipers are not recommended for use by untrained technicians. There are several fat types in human beings.
Some can harm your health, while others are beneficial to your system. One type of fat found in your body is the essential body fat, which we will be focusing on in this article.
Is it harmful or beneficial to your health? Health experts agree that too much fat can be dangerous to your body. It can cause conditions such as dyslipidemia, hypertension, type II diabetes, and other diseases related to obesity. But is that the case with essential fats?
Here is everything you need to know about essential body fat for men and women. As the most aptly named type of fat, essential fat is required for good health.
It plays a crucial part in regulating your body temperature, production of sexual hormones, vitamin absorption, among other benefits. Essential fat is the minimal amount of body fat required for normal physiological functions. These are not visible as they are located deep inside the body If you have essential fats in your body, then this means that you will be able to conduct all the physiological functions such as absorbing oxygen and so forth.
Essential fat is critical for your life, without it, you would probably be weak or dead. Hence, it is not surprising that they are located in the most important parts of your body. They include the following:. Essential fats are needed for normal physiological processes in your body, just as mentioned above. On the other hand, storage fat is found in your adipose tissue, beneath your skin, and around some of your organs.
It has the following main functions:. Essential and storage fats are types of body fat. They are all found in your body 6. This is the fat that is not needed to perform vital functions of the body. This non-essential fat is stored under your skin and around organs if it is in excess. The main types of non-essential fats include the following:. Having a healthy fat percentage provides the following general benefits:. If you wish to free yourself from all the extra pounds that have been weighting you down for way too long, start using the BetterMe app and overhaul your entire life!
The percentage of essential fats varies from one person to the other, depending on sex and age. Various theoretical values exist based on health, athlete, capacity, and so forth.
Their male counterparts only need Hence, the essential body fat for women is higher than that of men. Here is how the average percentages differ for women in specific groups and categories:. The following are the risks of having high contents of different types of fat:.
Brown, beige, and essential fats are useful to your body. They do not increase your risk of contracting any chronic disease Now that you know the importance of fats, risks, and normal percentages, how would you know the amount of fat in your body? Well, it turns out that body composition can be measured via several methods. Irrespective of their location, fat cells are composed of triglycerides with a density of 0. The density of each component is known.
The theoretical density of body water is 0. Hence, if you are immersed in water, and the volume of water displaced is measured correctly, your body fat percentage would be determined easily ADP uses the same principles as underwater weighing. The only difference here is that air will be displaced in place of water. The method is well suited for the elderly, disabled, children, obese, and other subjects that cannot be immersed in the water. It is, however, not as accurate as underwater weighing.
Accuracy will reduce as the amount of fat in the body rises 1. Infra-red beams will be transmitted into your biceps. The light will be reflected and also absorbed by your body fat. The amount absorbed can be calculated by subtracting the incident ray from the reflected ray. This is a more non-invasive, more rapid, easier, and safer method to use 2. This is the newest method of measuring the number of your body fats. X-rays of two different energies are used to scan your body.
One of the two is absorbed strongly by fats while the other is not. The total fat in the human body is classified into two types: essential fat and storage fat.
Essential fat is defined as the fat needed to maintain normal physiological functions. Essential fat is found in such tissues as muscles, nerve cells, bone marrow, intestines, heart, liver, and lungs. The percentage of essential fat is higher in women as it includes sex-specific fat, such as breast tissue, and other sex-related fat deposits.
Storage fat is the fat which is stored in the adipose tissue, mostly beneath the skin subcutaneous fat and around the major organs in the body. The storage fat is used as an insulator to retain body heat and as an energy substrate for metabolism. It also serves as a form of protection against physical trauma to the body.
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