How do other methods compare?

Hydrostatic Body Fat Testing (Hydro-Densitometry):

According to research, "Hydrostatic Body Fat Testing" is still the "Gold Standard" to which all methods of body fat testing still compare themselves. However, for informational purposes we would like to share other methods that are being used within the health, fitness, and medical community.

Advantages:

• The "Gold Standard" in body fat testing
• What other methods still compare to
• Fast test time (5-10 minutes)
• Most accurate technology available today
• Provides the best repeatability from test to test (tracking changes)
• Error rate around 1.5%
• Low equipment maintenance
• Has been the most accurate method for over 30 years

Disadvantages:

• Requires knowledge to administer test
• Being submerged underwater might be a little difficult for some (elderly)
• Must be able to blow out your air

Duel Energy X-Ray Absorptiometry Body Fat Testing (DEXA):

DEXA uses two x-ray energies to measure body fat, body fat percentage, muscle and bone mineral. One must lie down on an x-ray table while the machine scans the body. It takes the machine about 10 to 15 minutes to produce the image of the tissue.

Advantages:

• Under proper conditions it provides accurate results
• Error Rate is less than 2% under proper conditions
• Radiation exposure is relatively low but it is still new technology

Disadvantages:

• Very expensive equipment
• Costly
• Uses X-Rays
• Not easily accessible, or mobile
• Different DEXA equipment can produce different results
• X-Ray license required to use machine
• Frequent testing may be of concern due to radiation exposure

Caliper Body Fat Testing:

This is a small pinching device that measures subcutaneous body fat on your body. It has a +/- 3-8 percent error ratio based on technician skill, quality of caliper used, and number of sites pinched. Although it's quick and relatively easy to get it's more of an estimate of body fat this is because it only measures a few areas on your body and not the whole thing. Plus, it is very subjective to each person that does the testing.

Advantages:

• Easy to use once skill is mastered
• Does not require much time
• Noninvasive method
• Inexpensive way of estimating body fat percent
• Portable

Disadvantages:

• Technical sources of error
• Error rate up to +/-8%
• Mostly concerned with subcutaneous fat (under the skin)
• May not be an ideal measurement for those who are obese, or very lean.
• Reliability is highly dependent upon skill and the type of calipers used

Bio-Impedance (BIA) Body Fat Testing:

This measurement is done by hooking up an electrode to your foot or hand. An electrical low voltage impulse is then shot up one leg or arm and down the other to estimate body fat percentage. It measures the resistance in your body. Since body fat is a poor conductor of electricity, a lot of body fat will impede the current more so then lean mass.

Advantages:

• Fast and simple

Disadvantages:

• Error ratio +/-5 to 8 percent
• Results effected by hydration levels, food intake, and body temp
• Subjectivity is high
• Higher percentage of error than most people desire
• Overestimates lean people and underestimates obese people

Bod Pod Body Fat Testing:

This method tries to compare itself to the Hydrostatic method of body fat testing and it is based on similar principles. However, instead of using water it uses air displacement instead. This method has conflicting research reported on its results. Humidity, temperature, body hair and other environmental issues have been reported to negate the results of its body fat readings. According to Georgia State University, if each body fat test is performed correctly to the recommended guidelines, there is a +/-3% error. Likewise, a study done by McCrory, etal.* the bod pod has a validity of .93 using hydrostatic weighing as the criterion measure body fat percentage. Medicine and Science in Sport and Exercise, 27 (12): 1686-1691, 1995

Advantages:

• Fast 5 -10 minutes
• Not difficult to operate

Disadvantages:

• Error ratio +/-3 percent
• Results effected by h body temp of muscles
• Hydration levels can effect results
• Body hair can have an effect on the results
• Very expensive equipment
• Breathing pattern might affect the results
• Can have an Claustrophobic feeling

Futrex Body Fat Testing:

This method of assessing body fat is based on the principles of light absorption, reflectance, and near infrared spectroscopy. This is an infrared laser that is shot into your bicep muscle that emits an infrared light which passes through both fat and muscle and is reflected back to the probe. The test results change depending on what you program into the machine. Hydration levels can also dramatically change the results of the body fat readings.

Advantages:

• Non-invasive
• Fast
• Convenient

Disadvantages:

• Error ratio +/-5 to 6 percent
• Results effected by hydration levels, food intake, and body temp
• Subjectivity is high