Self-Reported Exercise Frequency Predicts the Accuracy of Using a Circumference Test in Senior Military Leaders

Abstract

1784 Procedures for estimating body composition using measurements of height, weight, and specific body circumferences (Circumference Test, CT) have been criticized for yielding biased estimates of body composition. That is, the equations under-predict percent body fat for obese individuals and over-predict percent body fat for lean individuals. Body fat standards have been used by the military services since the early 1980s, but few if any studies have examined the relationship between self-report exercise frequency and the accuracy of the CT in a population of over-40 males. PURPOSE: The present study examined the value of using self-reported frequencies of aerobic and strength training to predict the accuracy of the CT in measuring body composition as assessed by air displacement plethysmography (ADP) in 189 male senior military leaders. METHODS: Each subject's (mean age: 43.6 years) body composition and general exercise habits were measured as part of a comprehensive health and fitness assessment. Subjects completed a general exercise survey prior to their assessments. Body composition was measured using the CT according to Army Regulations first and then using ADP using the BOD POD (Life Measurement Instruments), where lung volume was measured. RESULTS: Subjects were categorized based on their responses to aerobic and resistance training frequency into low frequency (less than 3 times per week) of aerobic and resistance training (LOW, n = 53) or high frequency (3 times per week or more) of aerobic and resistance training (HIGH, n = 50). The LOW group (mean: 22.97 ± .53 and 26.55 ± .78, respectively) had significantly greater body fat using either the CT or ADP (p < .001 and p < .001, respectively) than the HIGH group (mean: 19.71 ± .54 and 21.54 ± .65, respectively). Furthermore, the difference between ADP and CT scores was significantly greater in the LOW group than the HIGH group (3.58 ± .47 and 1.83 ± .46, respectively, p < .01), indicating that the CT is more accurate in individuals who report higher frequency of aerobic and resistance training. CONCLUSION: Self-report data on the frequency of aerobic and resistance training is associated with increased reliability and validity of using circumference measures in assessing the body composition of senior military leaders.