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This cross-sectional study aimed to compare the horizontal and vertical force-velocity profile between female sprinters and hurdlers. Twelve high-level athletes (6 sprinters and 6 hurdlers) participated in this investigation. The testing procedures consisted of two maximal 40-m sprints and five to six vertical jumps with additional loads. For the sprint-acceleration performance, the velocity-time data, recorded by a high-speed camera, was used to calculate the variables of the horizontal F-V profile (theoretical maximal values of force [HZT-F 0 ], velocity [HZT-V 0 ], power [HZT-Pmax], the proportion of the theoretical maximal effectiveness of force application in the antero-posterior direction [RFmax], and the rate of decrease in the ratio of horizontal force [DRF]). The best trial of each vertical jumping condition, obtained by an optical measurement system, was used to determine the components of the vertical F-V profile (theoretical maximal values of force [VTC-F 0 ], velocity [VTC-V 0 ], and power [VTC-Pmax]). The female sprinters showed higher statistical differences for HZT-Pmax (2.46 ± 0.67, d = 2.1, p = 0.004), HZT-V 0 (0.45 ± 0.18, d = 1.4, p = 0.03), and RFmax% (2.9 ± 0.9%, d = 1.8, p = 0.01) than female hurdlers. No statistical differences were observed for HZT-F 0 (0.69 ± 0.3, d = 1.15, p = 0.07), DRF% (−0.24 ± 0.4%, d = 0.3, p = 0.62), VTC-F 0 (−2.1 ± 3.8, d = 0.3, p = 0.59), VTC-V 0 (0.25 ± 0.31, d = 0.5, p = 0.45), and VTC-Pmax (1.75 ± 2.5, d = 0.4, p = 0.5). Female sprinters are able to apply higher horizontally-oriented forces onto the ground during the acceleration phase than female hurdlers.

The aim of this study was to investigate the effects of heavy sled towing using a load corresponding to a 50% reduction of the individual theoretical maximal velocity (ranged 57–73% body mass) on subsequent 30 m sprint performance, velocity, mechanical variables (theoretical maximal horizontal force, theoretical maximal horizontal velocity, maximal mechanical power output, slope of the linear force–velocity relationship, maximal ratio of horizontal to total force and decrease in the ratio of horizontal to total force) and kinematics (step length and rate, contact and flight time). Twelve (n = 5 males and n = 7 females) junior running sprinters performed an exercise under two intervention conditions in random order. The experimental condition (EXP) consisted of two repetitions of 20 m resisted sprints, while in the control condition (CON), an active recovery was performed. Before (baseline) and after (post) the interventions, the 30 m sprint tests were analyzed. Participants showed faster 30 m sprint times following sled towing (p = 0.005). Running velocity was significantly higher in EXP at 5–10 m (p = 0.032), 10–15 m (p = 0.006), 15–20 m (p = 0.004), 20–25 m (p = 0.015) and 25–30 m (p = 0.014). No significant changes in sprint mechanical variables and kinematics were observed. Heavy sled towing appeared to be an effective post-activation potentiation stimulus to acutely enhance sprint acceleration performance with no effect on the athlete’s running technique.

AIM: The aim of this study was to examine the relationship between the performance of men’s and women’s finalists in the 100-m finals of IAAF World Championship 2017 and the mechanical properties of horizontal force-velocity-power (FVP) profile produced by each athlete. MATERIAL & METHOD: The spatio-temporal data from the 16 finalist sprinters (8 men and 8 women with 10.04 ± 0.12 s and 10.97 ± 0.09 s 100-m performance, respectively), were obtained from recordings of the distance-time curve in men’s and women’s 100-m finals during the IAAF World Championships 2017. The variables of horizontal FVP profile were calculated in order to determine the relationship between horizontal FVP profile [theoretical maximal values of force (F0), velocity (V0), and power (Pmax), the proportion of the theoretical maximal effectiveness of force application in the forward direction (RFmax), the rate of decrease in the ratio of horizontal force (DRF)] and the 10-m split-time, as well as the sprint running performance of men’s and women’s finalists in 100-m race. RESULTS: Spearman’s correlation analysis revealed highly negative linear associations between Pmax (r = −0.87, r2 = 0.76; p < 0.001), RFmax (r = −0.81, r2 = 0.66; p < 0.001), V0 (r = −0.78, r2 = 0.61; p < 0.001), and F0 (r = −0.66, r2 = 0.44; p = 0.005) with 100-m performance. The 10-m split-time was highly negatively linearly associated with RFmax (r = −0.98, r2 = 0.97; p < 0.001), F0 (r = −0.96, r2 = 0.93; p < 0.001), Pmax (r = −0.96, r2 = 0.91; p < 0.001), V0 (r = −0.62, r2 = 0.38; p = 0.011). DRF was not correlated with 10-m split-time or 100-m performance (p > 0.05). CONCLUSION: The mechanical properties of FVP profile strongly influenced the 100-m performance of men’s and women’s world-class sprinters. This study highlights the importance of the technical capability of world-class athletes to effectively orient the horizontal force onto the supporting ground during the initial sprint-acceleration.

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