The 10/5 repeated jumps test : are 10 repetitions and three trials necessary?

The purpose of this study was to identify whether ten repetitions and three trials were necessary to achieve stability in peak reactive strength index (RSI) during the 10/5 repeated jumps test (RJT). Twenty-five males, from multiple sports, performed three trials of the RJT on an in-ground force plate, with 90 seconds’ rest between trials. Intraclass correlation coefficients (ICC = 0.916−0.986) and coefficients of variation (CV ≤ 14.5%) were considered acceptable for all variables. Repeated-measures analysis of variance and Freidman’s tests revealed large and significant differences (p ≤ 0.006, η2 = 0.159−0.434, power ≥ 0.859) in ground contact time (GCT), jump height (JH), and subsequently RSI both between trials and repetitions. Pairwise comparisons revealed that repetitions 1−3 produced longer GCTs (p ≤ 0.05, d = 0.41−1.40), lower JHs (p ≤ 0.05, d = 0.31−0.56), and lower RSI values (p ≤ 0.05, d = 0.35−1.24). The shortest GCTs, greatest JHs and greater RSIs occurred between repetitions 7 and 10, with approximately 60% of peak RSIs occurring during these ranges. The sequential estimate technique revealed that seven repetitions were needed to attain stability in mean peak RSI. Non-significant (p = 0.554) and negligible differences (d ≤ 0.09) in the five best RSIs between trials were noted. One trial of the 10/5 RJT is sufficient to evaluate peak RSI in athletes and should reduce data collection time and fatigue