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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.

The purposes of this study were to a) compare a 4-min to an 8-min rest interval between composite training (jump-sprint combination) repetitions in a single session to allow for the recovery of neuromuscular and bounce drop-jump (BDJ) performance and b) investigate if super compensation would occur after 168hrs of rest. Twelve players were randomly assigned to either a 4-min or an 8-min rest interval group. Participants first completed a BDJ test to identify individual BDJ drop heights followed by a 20m sprint test. Seventy-two hours later, a composite training session of two repetitions (three BDJs followed by a 20m sprint after a 15s rest) with either a 4-min or an 8-min rest interval was performed. A three repetition maximum (3RM) back squat strength test, a BDJ, countermovement jump (CMJ) and a sprint performance test were completed 10-mins pre- and immediately post-session, and 168 hrs post-session. CMJ force (8-min group) and BDJ (height and reactive strength index (RSI)) measures decreased significantly post-session (4-min and 8-min groups; P ≤ 0.05). Pre-session to 168 hrs post-session, relative 3RM back squat strength and 20m sprint performance increased significantly for the 4-min group only (P ≤ 0.05). In conclusion, a 4-min composite training inter-repetition rest interval leads to a significant decline in BDJ measures (RSI and jump height) which may act as fatigue markers for monitoring. However, 4-mins provides sufficient recovery during the session which, in conjunction with 168 hrs of recovery, causes super compensation in neuromuscular performance in hurling players.

The purpose of this study was to firstly investigate the effects of treating latent myofascial trigger points (MTrPs) in the lower limb kinetic chain with respect to performance during sporting actions, as opposed to the traditional goal of pain management with active MTrPs. The second aim was to investigate the effects of dry needling (DN) on performance parameters over time to establish treatment timeframe guidelines prior to performance. Forty male athletes were assigned to four groups; rectus femoris DN (group 1), medial gastrocnemius DN (group 2), rectus femoris and medial gastrocnemius DN (group 3) and no DN (group 4). Subjects completed 6 sessions; familiarisation, baseline, immediately after DN, 48, 72 and 96 hours post intervention. Subjects performed squat jumps at 5 incremental loads and were recorded using the My Jump app (iOS) for jump height, power output, optimal force and optimal velocity. A between-within subject's ANOVA was used for statistical analysis. Results showed a significant increase in jump height in group 2 (gastrocnemius muscle only) from immediately post to 48 hours post intervention (p = 0.01), however, no other statistical significance was observed. From 48 hours onward, a trend for improved performance was observed, with jump height, power and velocity showing trivial increases. This study found improved jump performance from immediately post to 48 hours post DN of the gastrocnemius muscle only. This study suggests a likely immediate decrease in jump performance following DN, with levels increasing above baseline between 48 hours and 96 hours, which may have clinical significance.

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Byrne, PJ, Moody, JA, Cooper, SM, Callanan, D, and Kinsella, S. Potentiating response to drop-jump protocols on sprint acceleration: drop-jump volume and intrarepetition recovery duration. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to investigate the postactivation potentiation response first to bounce drop jump (BDJ) volume; second, BDJ intrarepetition recovery duration and recovery duration between BDJs and 20-meter (including 5- and 10-m split times) sprint performance. The study was undertaken in 2 parts, the first part compared different volumes of BDJs and the second part compared different BDJ intrarepetition recovery periods. The effect of recovery periods between the BDJs and the subsequent 20-m sprints was examined in both parts 1 and 2 (15 seconds, 4, 8, and 12 minutes). Fourteen (mean ± SD: age = 20.83 ± 1.26 years; height = 1.77 ± 0.04 m; and mass = 74.89 ± 6.07 kg) (part 1) and 15 (mean ± SD: age = 20.64 ± 1.00 years; height = 1.78 ± 0.06 m; and mass = 75.67 ± 6.28 kg) (part 2) male collegiate and club hurling players volunteered to participate. A randomized cross-over design was used to compare BDJ volumes (1, 2, and 3 sets of 3 repetitions) and BDJ intrarepetition recovery time (15 vs. 60 seconds) after a warm-up followed by 2 baseline 20-m sprints. The results in part 1 reported a significant improvement in 5- and 10-m sprint time for 1 set of 3 BDJs between baseline and 4 minutes (5 m: -2.34%, p = 0.04, effect size [ES] = -0.043; 10 m: -1.42%, p = 0.03, ES = -0.35), and baseline and 12 minutes (5 m: -3.33%, p = 0.03, ES = -0.57; 10 m: -2.13%, p = 0.01, ES = -0.52). Part 2 reported a significant improvement in 5-m sprint time between baseline and 15 seconds (5 m: -3.38%, p = 0.01, ES = -0.83; 10 m: -2.07%, p = 0.02, ES = -0.58) after the BDJs. The findings support the use of 1 set of 3 BDJs using a 15-second intrarepetition recovery period to maximize 5-, 10-, and 20-m sprint performance after 15 seconds of recovery after the final BDJ in hurling players. The acute response to this BDJ protocol proves to be time efficient and effective in acutely improving sprint acceleration.

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