Determining the relationship between maximal force and velocity to sprint running in elite women’s soccer

The purpose of this study was to investigate the relationship of acceleration (ACC) and maximal sprint speed (MSS) in elite women soccer players, utilizing Force-velocity (F-V) profiling, strength measure and bodyweight jumps. 39 elite women’s soccer players (24.3 ± 4.7 years) performed 40-metre (m) sprint testing with time intervals taken at the 10-m (acceleration - ACC), 30-m and 40-m marks (ie. 30-40-m segment as maximal sprint speed – MSS), five progressive loaded squat jumps (SJ) at increasing loads to determine individual F-V relationship and a countermovement jump (CMJ) test. From the F-V profile, theoretical maximal velocity (V0), theoretical maximal force (F0), maximal power (PMax) the one repetition maximal (1RM) back squat and 1RM relative to body mass was determined. ACC and MSS were highly correlated (r = 0.71, CL 0.55 to 0.82, P <0.001). CMJ demonstrated a moderate correlation (r = -0.45, CL -0.64 to -0.20) to ACC and moderate (r = -0.67, CL -0.80 to -0.50) to MSS. The F-V Slope of the group demonstrated on average 8 ± 34% from their optimal profile. An optimal profile did not appear to be related to sprint performance (r = 0.11, CL -0.16 to 0.36 and r = -0.12, CL -0.37 to 0.16 for ACC and MSS, respectively). V0, F0, 1RM and relative 1RM demonstrated a trivial to small relationship to ACC and MSS respectively. These finding suggest that since ACC and MSS have some related qualities and cannot be treated as independent of each other. A balance of F-V variables may be important to allow for maximal expression of PMax influencing lower-limb performance. Improving lower-limb ballistic performance at bodyweight through movements like the CMJ and SJ may be beneficial at improving both the ACC and MSS ability in elite womens soccer players.