Correction Factors for Body Mass in Military Physical Fitness Tests

Recent research findings combined with the theoretical laws of biological similarity make the compelling case that all physical fitness test items for the Army, Air Force, and Navy impose a 15-20% physiologic bias against heavier, not fatter, men and women. Using the published findings that actual scores of muscle and aerobic endurance scale by body mass raised to the 1/3 power, correction factor tables were developed. This correction factor can be multiplied by one’s actual score (e.g., push-ups, sit-ups, abdominal crunches, or curl-ups repetitions or distance run time) to yield adjusted scores that are free of body mass bias. These adjusted scores eliminate this bias, become better overall indicators of physical fitness relevant to military tasks, are easily applied to the scoring tables used in the present physical fitness tests, and do not reward body fatness. Use of these correction factors should be explored by all military services to contribute to more relevant fitness tests

Body Mass Bias in Exercise Physiology

In certain physically demanding occupations, especially the military, body mass bias has substantive implications. Work physiologists have determined that despite body mass bias in the common military physical fitness tests, the larger service members were often better performers of the physically demanding occupational tasks (Bilzon et al., 2002; Lyons et al., 2005; Rayson et al., 2000). That is, they could carry more, more easily evacuate casualties, and better engage in heavy materiel handling. Yet, the smaller personnel were achieving better scores on the physical fitness tests, the results of which have significant promotion and advancement implications (Vanderburgh & Mahar , 1995; Crowder & Yunker, 1996). This chapter chronicles the fundamentals and applications of body mass bias in fitness and exercise physiology, to include the theory and empirical data used to evaluate it. It also explains the real-world implications of body mass bias in the military services and how to mitigate its undesirable or unintended effects

Occupational Relevance and Body Mass Bias in Military Physical Fitness Tests

Recent evidence makes a compelling case that U.S. Army, Navy, and Air Force health-related physical fitness tests penalize larger, not just fatter, service members. As a result, they tend to receive lower scores than their lighter counterparts, the magnitude of which can be explained by biological scaling laws. Larger personnel, on the other hand, tend to be better performers of work-related fitness tasks such as load carriage, heavy lifting and materiel handling. This has been explained by empirical evidence that lean body mass and lean body mass to dead mass ratio (dead mass = fat mass and external load to be carried/lifted) are more potent determinants of performance of these military tasks than the fitness test events such as push-ups, sit-ups or two distance run time. Since promotions are based, in part on fitness test performance, lighter personnel have an advancement advantage, even though they tend to be poorer performers on many tests of work-related fitness. Several strategies have been proposed to rectify this incongruence including balanced tests, scaled scores, and correction factors - yet most need large scale validation. Because nearly all subjects in such research have been men, future investigations should focus on women as well as elucidate the feasibility of universal physical fitness tests for all that include measures of health- and work -related fitness while imposing no systematic body mass bias

Validity of Boston Marathon Qualifying Times

Purpose: To assess the validity of Boston Marathon qualifying (BMQ) standards for men and women. Methods: Percent differences between BMQ and current world records (WR) by sex and age group were computed. WR was chosen as the criterion comparison because it is not confounded by intensity, body composition, lifestyle, or environmental factors. A consistent difference across age groups would indicate an appropriate slope of the age-vs-BMQ curve. Inconsistent differences were corrected by adjusting BMQ standards to achieve a uniform percentage difference from WR. Results: BMQ standards for men were consistently ~50% slower than WR (mean 51.5% ± 1.4%, range 49.6–54.4%), thus demonstrating acceptable validity. However, BMQ standards for women indicated convergence with WR as age increased (mean 45.8% ± 13.7%, range 17.5–58.9%). The women’s BMQ standards were revised to yield a consistent 50% deviation from WR across age groups (50.9% ± 0.8%, range 49.2–52.2%). Applied to all 16,773 women in the 2012 Chicago Marathon, the suggested BMQ standards would lead to a 4.90% success rate, compared with 8.39% using the current standard. This compared with a 9.6% success rate for all 20,681 men of the same race. Conclusions:The current women’s BMQ standards appear too lenient for women 18–54 y and too strict for women 55–80 y but yield equitable gender representation in percentage of qualifiers. The current men’s and suggested women’s BMQ standards appear valid but would lead to approximately 40% fewer women achieving BMQ standards

Body Weight Penalties in the Physical Fitness Tests of the Army, Air Force, and Navy

Recent research has empirically documented a consistent penalty against heavier service members for events identical or similar to those in the physical fitness tests of the Army, Air Force, and Navy. These penalties, not related to body fatness, are based on biological scaling models and have a physiologic basis. Using hypothetical cases, we quantified the penalties for males, 60 vs. 90 kg body weight, and females, 45 vs. 75 kg, to be 15-20% for the fitness tests of these three services. Such penalties alone can adversely impact awards and promotions for heavier service members. To deal equitably with these penalties in a practical manner, we offer two recommendations: Implementation of revised fitness tests with balanced events: penalties of one event against heavier service members are balanced by an equal and opposite bias against lighter service members. Development of correction factors which can be multiplied by raw scores to yield adjusted scores free of body weight bias

Derivation of an Age and Weight Handicap for the 5K Run

The adverse effect of increasing age and/or body weight on distance run performance has been well documented. Accordingly, nearly all five kilometer (5K) road races employ age categories and, sometimes, a heavier body weight classification. Problems with such conventions include small numbers of runners within older age categories and the advantage given to the lightest runners within each weight category. We developed a 5K Handicap (5KH), a model that calculates an adjusted run time based on the inputs of actual 5K run time, age, and body weight for men and women. This adjusted time, then, can be compared between runners of different ages and body weights. The purpose of this paper was to explain, in detail, the derivation of the 5KH formula using published theoretical and empirical findings on age, body weight and distance run time relationships. To our knowledge, the 5KH is the first such model and overcomes the problems associated with being heavier within one weight class and having too few runners in certain age categories. We are currently undertaking large-scale validation studies and evaluation of its race day implementation

Body Mass Bias in a Competition of Muscle Strength and Aerobic Power

Recently, a fitness competition called the Pump and Run (PR) has been popularized. Composed of 2 events, a 5-km road race time (RT) in seconds and a maximal-repetition bench press (BPR) with resistance based on a percentage of body mass (M), the final score (RTadj) equals RT - 30(BPR). From published findings, the authors hypothesized that the PR would impose a bias against heavier competitors. Furthermore, the potential for age bias in this event has not been evaluated. Therefore, the purpose of this study was to investigate M and age bias in the PR for men and women. For 74 female and 343 male competitors in a large PR event, RT, BPR, M, and age were collected from official competition results. Two subsamples were randomly created from the original sample: the validation (VAL) (54 women and 258 men) and the cross-validation (CVAL) (20 women and 85 men). For the VAL sample, the RTadj showed significant bias against heavier runners (women r2 = 0.35; men r2 = 0.28;P \u3c 0.01 for both) but no age bias (women r2 = 0.04; men r2 = 0.005; P \u3e 0.05 for both). Using allometric modeling, the authors developed a set of M-based correction factors to be multiplied by each RTadj to yield new adjusted run times (NRTadj) that would be free of M bias. As applied to the CVAL sample, the NRTadj values virtually eliminated the M bias (women r2 = 0.04; men r2 = 0.002; P \u3e 0.05 for both) of the current PR scoring system and retained the absence of age bias (women r2 = 0.02; men r2 = 0.0002; P \u3e 0.05 for both). The authors recommend the use of the NRTadj scores for future PR competitions

Validation of a 5K Age and Weight Run Handicap Model

Though increasing age and body weight (BW) have been widely known to be associated with slower distance run times, the common convention in 5K road races is to categorize competitors by age and, sometimes, BW. This has the disadvantage of assigning only small numbers of competitors to age categories and giving advantage to runners close to the minimum age or BW values allowable. Using recent advances in the modeling of distance run performance by BW combined with empirical evidence quantifying the independent effect of age on cardiovascular endurance, we previously published the derivation of the 5K Handicap (5KH), an age and BW handicap model for the 5K road race. With the inputs of age, BW and actual run time, the 5KH computes an adjusted run time which can be used to compare runners of different age and BW within the same gender. In this study, we field tested the 5KH in two local races with 275 men and 126 women. Results suggest that the 5KH eliminates the age and BW bias, and may provide more incentive for older and heavier runners to compete. Furthermore, the BW bias in the 5K tended to be lower for women than for men. The first scientifically-based age and BW graded system, the 5KH appears valid for both genders and may have application for other race distances and fitness testing environments

Contributions of Body Fat and Effort in the 5K Run: Age and Body Weight Handicap

The 5K handicap (5KH), designed to eliminate the body weight (BW) and age biases inherent in the 5K run time (RT), yields an adjusted RT (RTadj) that can be compared between runners of different BW and age. As hypothesized in a validation study, however, not all BW bias may be removed, because of the influences of body fatness (BF) and effort (run speed; essentially the inverse as measured by rating of perceived exertion (RPE)). This study\u27s purpose was to determine the effects of BF and RPE on BW bias in the 5KH. For 99 male runners in a regional 5K race (age = 43.9 ± 12.1 years; BW = 83.4 ± 12.9 kg), BF was determined via sum of three skinfolds just before the race. RPE, on the 20-point Borg scale, was used to assess overall race effort on race completion. Multiple regression analysis was used to develop a new adjusted RT (NRTadj, the RTadj corrected for BF and RPE), which was computed for each runner and then correlated with BW to determine bias. Indicative of slight bias, BW was correlated with RTadj (r = 0.220, p = 0.029). Both BF (p = 0.00002) and RPE (p = 0.0005) were significant, independent predictors of RTadj. NRTadj was not significantly correlated with BW (r = 0.051, p = 0.61), but BF explained 90%, and RPE explained only 6%, of the remaining BW bias evidenced in the 5KH. The previous finding that the 5KH does not remove all BW bias is apparently accounted for by BF and not RPE. Because no handicap should be awarded for higher BF, this finding suggests that the 5KH, for men, appropriately adjusts for the age and BW vs. RT biases previously noted

Load Carriage Distance Run and Pushups Tests: No Body Mass Bias and Occupationally Relevant

Recent research has demonstrated body mass (M) bias in military physical fi tness tests favoring lighter, not just leaner, service members. Mathematical modeling predicts that a distance run carrying a backpack of 30 lbs would eliminate M-bias. The purpose of this study was to empirically test this prediction for the U.S. Army push-ups and 2-mile run tests. Two tests were performed for both events for each of 56 university Reserve Offi cer Training Corps male cadets: with (loaded) and without backpack (unloaded). Results indicated signifi cant M-bias in the unloaded and no M-bias in the loaded condition for both events. Allometrically scaled scores for both events were worse in the loaded vs. unloaded conditions, supporting a hypothesis not previously tested. The loaded push-ups and 2-mile run appear to remove M-bias and are probably more occupationally relevant as military personnel are often expected to carry external loads