Allometric Scaling of Strength Scores in NCAA Division I-A Football Athletes

Abstract

This study examined population-specific allometric exponents to control for the effect of body mass (BM) on bench press, clean, and squat strength measures among Division I-A collegiate football athletes. One repetition maximum data were obtained from a university pre-season football strength assessment (bench press, n = 207; clean, n = 88; and squat n = 86) and categorized into 3 groups by positions (line, linebacker, and skill). Regression diagnostics and correlations of scaled strength data to BM were used to assess the efficacy of the allometric scaling model and contrasted with that of ratio scaling and theoretically based allometric exponents of 0.67 and 0.33. The log-linear regression models yielded the following exponents (b): b = 0.559, 0.287, and 0.496 for bench press, clean, and squat, respectively. Correlations between bench press, clean, and squat to BM were r = -0.024, -0.047, and -0.018, respectively, suggesting that the derived allometric exponents were effective in partialling out the effect of BM on these lifts and removing between-group differences. Conversely, unscaled, ratio-scaled, and allometrically scaled (b = 0.67 or 0.33) data resulted in significant differences between groups. It is suggested that the exponents derived in the present study be used for allometrically scaling strength measures in National Collegiate Athletic Association Division I-A football athletes. Use of the normative percentile rank scores provide coaches and trainers with a valid means of judging the effectiveness of their training programs by allowing comparisons between individuals without the confounding influence of BM.

Allometric Scale Corrects Performance Outcomes in Special Judo Fitness Test

“…In contrast, the 0.67 exponent is generally used to correct performance outcomes in muscle function tests with external forces [10,13]. Hence, although some suggest the use of non-normalized performance outcomes in tests involving rapid movements [20,21], the present study provides evidences that performance outcomes in specific judo tests such as SJFT may be best interpreted when allometrically corrected.…”

“…In this regard, most performance variables (e. g., TNT) are composed of displacements while maintaining posture, taking into account the number of repetitions [19]. Indeed, the use of a -0.33 exponent has been suggested as appropriate to correct performance outcomes from tests that require the maintenance of posture as well as from tests measuring the number of repetitions of an action [20]. In contrast, the 0.67 exponent is generally used to correct performance outcomes in muscle function tests with external forces [10,13].…”

Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight

“…In addition to the age-comparisons, we explored the relationships among muscle mass and quality and indices of neuromuscular function. After removing the influence of bodyweight, which has been shown to exert a significant influence on neuromuscular measurements ( Folland et al 2008 ; Oba et al 2014 ; Weir et al 1999 ) and indeed displayed collinearity with MVIT, SMM, mCSA, MQ, PA, and the EMG-T variables in the present investigation, both our indicators of muscle mass (i.e., SMM and mCSA) and quality (i.e., EI, PA, MQ) were consistently, moderately related to the neuromuscular function indices (i.e., MVIT, Slope 40 /Slope 70 , Intercept 40 /Intercept 70 ). In addition to the aforementioned possibility that the age-related differences in MVIT and the EMG-T slopes and intercepts were caused by age-associated reductions in voluntary activation, it is also highly plausible and, in our opinion, more likely that differences in muscle mass and quality are responsible.…”

“…Any non-normally distributed variables were analyzed using Mann-Whitney tests. Pearson’s partial correlation coefficients were calculated to examine the relationship among all of the dependent variables after adjusting for bodyweight, because bodyweight has been shown to exert a substantial influence on neuromuscular function outcomes ( Folland et al 2008 ; Oba et al 2014 ; Weir et al 1999 ) and it displayed collinearity with the other neuromuscular function variables in this study (i.e. MVIT, SMM, mCSA, MQ, PA, and EMG-T slopes and intercepts).…”

Allometric Scaling of Wingate Anaerobic Test Scores in Young Soccer Players

“…"When comparing participants using unscaled data (absolute values), larger participants typically achieve a higher score, with a positive correlation between the variable and BM. When using ratio scaling, the scaled variable is generally overcorrected, thus the smaller participants have an advantage, resulting in a negative correlation between the scaled variable and BM (Oba et al, 2014). For comparative purposes, normalisation of strength measures to body size using allometric scaling is recommended (Folland et al 2008;Blair et al, 2009;Stefanova, 2002;Stefanova, 2002a,b).The allometric scaling has been shown to be an important tool to control the effect of body mass when interpreting WAnT results.…”