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A-31 Free Communication/Poster – Military and Public Safety Fitness: MAY 30, 2007 7:30 AM - 12:30 PM ROOM: Hall E

Creation of a Correction Factor via Allometry to Eliminate Body Mass Influence on the Army's Physical Fitness Test: Board #157 May 30 11:00 AM - 12:30 PM

Crowder, Todd A.; Vanderburgh, Paul M. FACSM; Sturdivant, Rodney X.; Johnson, Christopher A.; Leth, Allen D. Jr; Gelineau, Joseph C. II; Newsom, Joel D.; Daniels, Gregory L.; Schaefer, Stacy M.

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Medicine & Science in Sports & Exercise: May 2007 - Volume 39 - Issue 5 - p S201
doi: 10.1249/01.mss.0000273753.94733.8d
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We previously reported via allometry the Army's Physical Fitness Test (APFT) should be scaled either by event or total score to mitigate body mass (BM) on results for men.

PURPOSE: Create a correction factor which eliminates lean body mass (LBM) influence on the APFT.

METHODS: Male (n = 377) & female (n = 94) college-age students were tested during two graded periods on the APFT. Percent body fat was assessed via sum of three skinfolds.


Allometry exponents (AE) with 95% Confidence Intervals (CI) were created for each event & total score (Men = −.23 (−.13 to -.33); Women = −.20 (+.08 to -.48) (95% CI) based on the influence of LBM only. A multivariate model (HT & LBM) indicated HT was not significant; thus, adjusting by LBM appeared warranted.

RESULTS: Because the women's 95% CI included zero, we determined that no adjustment should be made to the women's APFT score. Opting for a single APFT adjustment for men, group BM mean was set as the reference standard to create a correction factor: (BM.23 *81.1(−.23)), such that this quantity would be multiplied by APFT score to yield an adjusted score free of LBM bias. Using simple regression, a more user-friendly expression of this correction factor, the Composite Score Adjustment (CSA) was determined as CSA = .77 + .0028* BM (kg). We compared CSA (LBM-free APFT score) to: allo metric ally scaled score (adj R2 = .995), LBM (adj R2 = .0003) & BM (adj R2 = .007), thus LBM & BM influences are removed. The CSA's for a 64 kg and 118 kg man would yield a 5% lower and a 10% higher APFT score respectively. CONCLUSIONS: LBM adjustment factors are necessary regarding the APFT score for men but not women. The user-friendly CSA's for the APFT are valid and appropriate for men. Furthermore, this convention may be appropriate for other fitness tests.

© 2007 American College of Sports Medicine