A comparison of methods used to identify 'optimal' drop height for early phase adaptations in depth jump training

The purpose of this study was to compare 2 methods of identifying an appropriate drop height for bounce depth jump (DJ) training, which aimed to improve reactive strength and countermovement jump (CMJ) performance. The maximum jump height (MJH) method was compared to the reactive strength index (RSI) method. The first part of the study identified each participant's drop height for both methods and determined the extent to which both methods differed. The subsequent part of the study used an 8-week bounce DJ training program to compare the effectiveness of the MJH and RSI methods. Twenty-two male participants volunteered. There was a significant difference between the MJH and the RSI methods in the optimal drop height they identified (median = 0.40 and 0.30 m, respectively), with 19 participants exhibiting a difference of 0.10 m or more. These 19 participants were assigned to 1 of 3 training groups: a control, an MJH method, and an RSI method group. The results demonstrated a significant increase in pre to posttraining in reactive strength (MJH: 27.3 +/- 18.7%, p = 0.025; RSI: 11.8 +/- 10.1%, p = 0.019) and CMJ performance (MJH: 9.9 +/- 5.2%, p = 0.009; RSI: 9.2 +/- 4.8%, p = 0.006) in both the MJH and RSI groups, respectively, with no change in the control group. The study concluded that either method can be used to identify the optimal drop height in bounce DJ training to increase CMJ performance, but the MJH method should be used to improve reactive strength.