Your members may not realize that all muscle is not created equal. Here’s how you can help them build-and maintain-the muscle they really want.
There is a growing awareness of the importance of developing and maintaining muscle mass to improve health and quality of life. Conventional body composition techniques focus on the measurement of body fat and only provide an estimate of lean body mass. The reason for this focus, of course, is that accurate tools and techniques for measuring muscle mass and quality are not readily available in most fitness clubs.
X-ray computed tomography (CT) and magnetic resonance imaging (MRI) have been shown to be accurate tools for measuring muscle mass in children and adults. What makes these techniques particularly effective is that they can quantify the amount of fat that is within the muscle. This interstitial adipose tissue (IAT) is known to increase with obesity and age. Caliper measurements can only directly measure the subcutaneous fat thickness and use formulas derived from large studies to estimate the total body fat percentage, which includes the contribution from IAT. The increase in IAT and visceral fat with age is the primary reason that caliper formulas are dependent on age. For most body fat percentage formulas the calculated %BF for a constant total caliper thickness increases approximately 1% per decade. In many cases this increase will over estimate the IAT for individuals that have maintained a healthy diet and exercise program for many years.
Alternative techniques that have been applied to measure muscle mass include a variety of anthropometric measurements which commonly use arm or thigh circumference in combination with skin fold caliper measurements. Unfortunately, these techniques do not make direct measurements of IAT and consequently are less reliable then CT or MRI. Clearly, CT and/or MRI are highly accurate, but the cost and the skill required to perform and analyze these medical procedures prohibits their use in fitness clubs. Muscle metabolites, for example, creatinine and the amino acid 3-Methylhistidine, have also been used to estimate muscle mass. These types of tests require urine samples and controlled diet in preparation for measurements; this is not practical in most fitness centers. Bioelectrical impedance analysis has also been used to assess muscle mass, but these techniques can be sensitive to hydration and frequently provide inconsistent measurements.
Another technique that has been used to evaluate muscle quality and structure is ultrasound imaging. Ironically, ultrasound imaging has a long history and is used regularly to determine the quality of beef and in particular whether it is marbled or not (i.e., IAT). Up until recently, these ultrasound imaging systems were expensive which limited their use by personal trainers and fitness clubs. Luckily, new low-cost handheld ultrasound systems are now becoming available. They can provide trainers with a valuable tool to assess muscle quality and muscle mass. You can be sure that in the near future muscle assessment will become an important element of any fitness program.
Luiz Da Silva, PhD is the CTO of IntelaMetrix, Inc. He can be contacted at 877/838-9918, or by email at ldasilva@intelametrix.com .
