The purpose of this study was to use observational analysis to evaluate the relationships between variables measured at the start of the men's 110 hurdles event and race performance itself. Data were obtained for competitors in 2015 IAAF World Athletics Championships, in Beijing, China. The athletes' start was quantified by reaction time and time to the first hurdle; their action over the first hurdle was quantified by the takeoff distance (i.e., the distance from the last step to the first hurdle), the landing distance, and the total distance in the air over the first hurdle. Regression analyses revealed that the combination of one measure of the start (either reaction time or time to the first hurdle) and the measure of propulsion over the first hurdle (distance in air over the first hurdle) predicted performance (SEE = 0.23 s in the heats, SEE = 0.16 s in the semifinals , SEE = 0.09 s in the finals). In addition, looking at performances in the finals, where all athletes with available data used a seven-step approach to the first hurdle, inclusion of stride length data improved the prediction somewhat (SEE = 0.07 s). The results demonstrate that a combination of a fast start, rapid acceleration, and strong drive over the first hurdle quantifiably explains and contributes to performance in the men's 110 m

Jim énez-Reyes, P, Casado, A, Gonz ález, JE, and Rodríguez-Fern ández, C. Influence of hurdling clearance on sprint mechanical properties in high-level athletes. J Strength Cond Res 36(3): 827-831, 2022-Short hurdling races are sprint races in which athletes must also clear 10 hurdles. Assessing the force-velocity (F-V) profile in sprinting has been found useful for implementing individualized training programs and determining the mechanical effectiveness in force application. This study therefore compared the sprint mechanical F-V profile between flat and hurdle conditions to distinguish which mechanical capacity (i.e., maximum force [F 0 ], maximum velocity [V 0 ], or maximum power [P max ]) is required to optimize performance in hurdling races. Twenty-two athletes (10 men and 12 women, aged: 22.4 6 3.6 years old) competing at the national and elite performance levels conducted 2 maximal sprints of 40 m in both flat and hurdle conditions. F 0 , V 0 , FVslope, P max , and decrease and maximal ratio of horizontal force (DRF and RFpeak, respectively) were assessed for each condition. A higher F 0 (effect size [ES] 5 1.69) and a lower V 0 (ES 5 2.08), DRF (ES 5 3.15) and RFpeak (ES 5 1.31) were found in the hurdle condition than in the flat condition. No significant differences were observed between conditions for P max (ES 5 0.01). These results support the potential of using the F-V profile to monitor sprint mechanics to optimize specific and individualized sprint training programs for hurdlers and sprinters. Coaches of hurdlers should thus consider implementing in their training routines exercises that were found to be effective on the development of F 0 , such as heavy load resisted sprints.