THE ASSOCIATION BETWEEN FAT DISTRIBUTION PATTERNS AND HAMSTRING STRENGTH IN DIVISION I ATHLETES

Nevaeh R. Nez1, Keanu Lettley1, Brett Pexa2, Christopher Johnson2, Malia Blue1. 1University of North Carolina Chapel Hill, Chapel Hill, NC. 2High Point University, High Point, NC. Background: There are a wide variety of body statures and compositions among Division I athletes depending on sport and position. Different fat distribution patterns (e.g., storing more fat abdominally) may impact lower extremity strength which may also be a risk factor for injury. Therefore, the purpose of this study was to evaluate the association of trunk:leg fat mass (TLFM) ratio and leg fat percentage (leg%fat) and eccentric hamstring strength in Division I athletes. Methods: Thirty-nine Division I athletes enrolled in the current study (74% female; Age: 18.8±1.2 yrs, Ht: 175.4±8.6 cm, Wt: 72.8±11.0 kg). Hamstring strength was evaluated using a Nordbord and normalized to body mass. In a kneeling position, participants\u27 ankles were secured and they were asked to gradually lean forward resisting movement with both legs. To measure leg%fat ([right leg FM+left leg FM]/total leg mass x 100) and TLFM (trunk FM/[right leg FM+left leg FM]) each participant completed a dual energy x-ray absorptiometry scan. Pearson correlation coefficients assessed the association between hamstring strength and body composition in males and females separately. Results: In males, there were no significant associations between TLFM and right (R) or left (L) normalized hamstring maximal force (nMaxF; R: r=0.17; L: r=0.21, p\u3e0.05) or normalized hamstring average force (nAvgF; R r=0.18; L: r=0.16, p\u3e0.05). Leg%fat and right nMaxF were negatively associated (r=-0.64, p=0.045). However, there were no other significant associations between leg%fat and strength (nMaxF L: r=-0.57; nAvgF R: r=-0.61; L: r=-0.53, p\u3e0.05). In females, there were no significant associations between TLFM and nMaxF (R: r=-0.06; L: r=-0.04, p\u3e0.05) or nAvgF (R: r=-0.11; L: r=-0.10, p\u3e0.05). Similarly, there were no significant associations between leg%fat and nMaxF (R: r=-0.22; L: r=-0.20 p\u3e0.05) or nAvgF (R: r=-0.16; L: r=-0.15, p\u3e0.05). Conclusions: Overall, the results of this study suggest that varying fat distribution patterns may not significantly impact eccentric hamstring strength in an athletic population. However, the influence of %leg fat on maximal strength should be evaluated further. Additionally, future research should evaluate how fat distribution may influence different strength assessments (e.g., hip strength) and biomechanics of movement to further understand if varying fat distribution can influence injury risk and performance in athletes