Body-fat testing: What’s the best pption?

Body-Fat Testing: What's the Best Option?

Well, it is definitely that time of year again when the waistline seems to expand. And soon, gyms and health clubs across the nation will be flooded with a sudden influx of eager participants ready to achieve their new found resolutions of health and fitness. Some of these people may be completely new to exercise; some may be returning to it after a lengthy vacation. Whatever the scenario may be, I believe everyone should have a firm understanding of what their current fitness level is. Accurate testing and evaluation is a great way to discover where your personal fitness level is, even if the results are not what you had hoped for. In particular, body- fat testing can give people a firm understanding of where they are physically and where they need to go. It provides a base line from which to work from. And it is also a great way to keep track of progress, when done on a regular basis. But there is more than one body- fat testing option to choose from. Which is the best? Which is the most accurate? In this article, I will be discussing four different methods of body- fat testing and the advantages and disadvantages of each one.

Hydrostatic Weighing: This form of body-fat testing is considered to be the "gold standard" of body composition assessment. It is also known as under- water weighing as it involves suspending a client into a tank of water, while seated to a chair that is attached to a scale. Body density is calculated from the relationship of normal body weight to under water weight. Body- fat percentage is calculated from body density. This method is most accurate when combined with a measurement of residual volume (the amount of air left in the lungs after a complete expiration).When residual volume is estimated from a formula, the accuracy of the hydrostatic method can be significantly decreased. While this method is by far the most accurate, it can also be very costly and takes a significant amount of time.

Bioelectrical Impedance: This method of body- fat testing is based on the principal that the conductivity of an electrical impulse is greater through lean tissue than through fatty tissue. An imperceptible electrical current is passed through two pairs of electrodes, which are placed on hand and foot. The analyzer measures the body's resistance to electrical flow and computes body density and body- fat percentage. The client must lie still, with wrist and ankle electrodes placed accurately. They should be well hydrated and not have exercised in the past six hours or have consumed any alcohol in the past twenty- four hours. This method has proven to be fast and easy but can cost between $300 to $5,000 depending on the design and report-generation capabilities. Results can also be altered if the client has not adhered to the before mentioned restrictions. Certain body- fat scales are now available for around $100 but they tend to be far less accurate because they tend to not differentiate between body types and thus don't always provide consistent readings.

Skinfold Measurements: This is the method that I personally use and it is a very inexpensive and reliable way to assess body composition. However, it is very important that the person taking the measurements is very accurate in their assessment. It is also highly recommended that the same person take future measurements. This method is based on the belief that approximately 50% of total body fat lies under the skin, and involves measuring the thickness of the skinfolds at standardized sites. These measurements are summed and applied to one of many equations available. The equations calculate body density, with percent fat being calculated from the same formula used for hydrostatic weighing. Calculation is simplified through the use of a table that most gyms and/ or personal trainers have access to. Calipers specifically designed for skinfold measurement are the only equipment needed for this method of body- fat assessment, and range in cost from $3 to $300. This method should follow a standardized approach:

1. Traditional anatomical landmarks should be used (these are different between men and women).
2. All measurements should be taken on the right side of the body.
3. Only people trained in this technique should be allowed to take measurements.
4. The caliper measurements should be taken approximately one or two seconds after the trigger has been released and should be read to the nearest 0.5 millimeter.
5. A minimum of two measurements should be taken at each site, with at least 15 seconds between measurements to allow the fat to return to its normal thickness.
6. Measurements should be continued until two measurements vary by less than one millimeter.

Improper site determination and measurement are the two primary sources of error when using this method, which is why only skilled practitioners should be allowed to take the measurements. Skinfold measurements should also not be taken after exercise because the transfer of fluid to the skin could result in overestimations.

Skinfold measurements for men are taken at the chest, thigh, and abdomen. Measurements for women are taken at the triceps, thigh, and suprailium. After taking three satisfactory measurements, the sum of those measurements are connected with the client's age in the before mentioned chart that is accessible through most gyms, health clubs, and personal trainers. That chart will give the client an estimated body- fat percentage.

I personally encourage my clients to focus less on their estimated body percentage and more on the specific skinfold measurements. If I have a male client who measures 40 mm at his abdomen skinfold, I encourage him to aim for a realistic goal of lowering that percentage by 10mm within the next two months. When he sees that number decreasing, he will know that he is making progress and motivation therefore becomes greatly enhanced. He will then become even more determined to decrease that measurement even further. While some people may not exactly look forward to having these measurements taken, the end result will speak for itself and they will be very happy that they did it. Progress and results is what it's all about and taking accurate body- fat measurements is a great way to see those results. So, what are you waiting for? Go do it!

Michael Elder has been working as a fitness professional in Chicago for the last thirteen years. He comes from a background in gymnastics and is certified as a personal trainer through the American Council on Exercise (ACE). He can be contacted directly through his website, www.MichaelElder.com.