OC15 Body composition related to force-velocity mechanical profile

Abstract

<h3></h3> Relatively few studies have explored the effects of body composition on jumping performance. Recently, Copic <i>et al.</i> (2014, JSCR, <i>in press</i>) showed that percent of body fat and body muscle could be predictors of jumping performance in non-trained women. Since power capabilities depends on both force and velocity mechanical qualities, the effect of body composition on power or performance can be associated to effect on maximal force and/or velocity. The aim of this study was to experimentally test the influence of body composition on lower limb force–velocity (FV) mechanical properties. Squat jump (SJ) (Samozino <i>et al.</i>, 2010, <i>J Theor Biol, 264</i>(1):11–18) and countermovement jump (CMJ) (Jiménez-Reyes <i>et al</i>, 2014, EJAP, <i>in press</i>) FV<i> profiles </i>were computed in healthy subjects and related to lean mass (LM) adjusted for whole mass (body weight) and percent of body fat (BF). 26 subjects (27 + 4 y) with different physical condition performed maximal SJ and CMJ against additional loads. From vertical ground reaction force and displacement data individual linear F-V relationships (<i>S_Fv</i>, slope of the F-V curve, in N.s.kg⁻¹.m⁻¹) were determined using the best trial for each condition and used to compute individual maximal power, force and velocity. Dual-energy X-ray absorptiometry (Norland XR-46) were performed by the same qualified researcher. BF is inversely related to SJ-maximal height (<i>hmax</i>) (r = 0.27, p = 0.191) and CMJ-<i>hmax </i>(r = 0.376, p = 0.064), which is in line with Slinde <i>et al.</i> (2008, <i>JSCR</i>, <i>22</i>(2):640–4). LM is related to SJ-<i>hmax</i> (r = 0.276, p = 0.18), CMJ-<i>hmax</i> (r = 0.428, p = 0.033) which is expected according to Copic <i>et al</i> (2014, JSCR, <i>in press</i>). We found an interesting relationship between LM and SJ-<i>S_Fv</i> (R = 0.424, p = 0.035) but not in CMJ-<i>S_Fv</i> (R = 0.089, p = 0.672). It indicates that SJ-<i>S_Fv</i> could depend on LM meanwhile CMJ-<i>S_Fv</i> could be influenced by other biological features.