Effects of sprint training on kinematic and kinetic variables of countermovement jump and drop jump

The purpose of this study was to investigate the effect of a four-week sprint training protocol on various kinematic and kinetic variables for the countermovement vertical jump (CMJ) and drop jump (DJ). Jump training has been used to enhance sprint training. However, there is a dearth of research on whether sprint training affects jumping performance. Since both types of activities involve applying force to increase propulsion and, with sprinting and DJ, regulation of vertical stiffness to promote optimal propulsion is involved, then it is appropriate to investigate the possible effects of sprinting to jumping. Fourteen recreationally active college students (age: 23.07 years ± 2.97; height: 170.49 cm ± 7.19; mass; 67.46 kg ± 10.18; seven males and seven females) with normal body mass index readings performed a four-week sprint training protocol. The sprint training protocol involved two training sessions per week while sprinting as fast as possible with maximal rest in between repetitions. CMJ and DJ performance were assessed the week before and after the sprint intervention. Jump height and peak propulsive force (PPF) were assessed for the CMJ. Jump height, PPF, ground contact time, reactive strength index (RSI), propulsive impulse, minimum vertical center of mass displacement (CoMmin) and vertical stiffness were measured for the DJ. Height jumped was higher during the CMJ following sprint training (t(13) = -2.648, p = 0.020). Although PPF (t(13) = -1.525, p = 0.151), did not significantly differ, there was an increasing trend post-test. Height jumped during the DJ was higher following sprint training (t(13) = -3.795, p = .002). However, no statistically significant differences were found for PPF (t(13) = 0.452, p = 0.659), ground contact time (t(13) = -0.280, p = .784), RSI (t(13) = -1.094, p = 0.294), propulsive impulse (t(13) = -1.141, p = 0.274), CoMmin (t(13) = 1.137, p = .276) or vertical stiffness (t(13) = 1.502, p = 0.157). An increasing trend was found with PPF and a decreasing trend was found with vertical stiffness. The results show that sprinting may improve CMJ and DJ height. However, further research would be needed on the exact mechanisms that allow this phenomenon to occur.