@Article{Montoro-Bombú2026,
journal="Biology of Sport",
issn="0860-021X",
volume="43",
number="1",
year="2026",
title="Effect of plyometric training based on the integral reactive 
strength index of national-level jumpers and sprinters. 
A randomized crossover trial",
abstract="The Integral Reactive Strength Index (IRSI) has recently been described in the literature as a new indicator that normalizes the reactive strength index based on fall height. This study aimed to compare the effects of a plyometrictraining program based on IRSI versus a traditional jump training program on spatiotemporal variables associated with the performance of national-level jumpers and sprinters. A randomized, crossover trial with three parallel groups was conducted. Twenty-seven male track and field athletes were divided into three groups. The G-RT1 group consisting of 9 participants, began the experiment with IRSI based training as the load prescription criterion. The G-PT2 group consisting of 10 participants, started the experiment with traditional plyometric training, and the control group, G-CT3, consisting of 8 participants, continued its usual training. After 19 weeks, a two-way mixed analysis of variance for the G-RT1 group found a significant interaction and large effect sizes (ES) in the group-time relationship in the 60 m dash ( p  ≤ 0. 001;  f  = 101.2; η 2  = 0.089), and the standing triple jump (STJ) ( p  ≤ 0.001;  f  = 119.8; η 2  = 0.031). The G-PT2 also showed better results, but the ES was lower for the standing long jump ( p  ≤ 0.001;  f  = 52.7; η 2  = 0.045), and the STJ ( p  ≤ 0.001;  f  = 22.7; ηp 2  = 0.011). Meanwhile, the G-CT3 did not show significant improvement at the end of the program. It is concluded that the IRSI-based plyometric training program produces better results than the traditional program. The use of IRSI-based improves individualization, emphasizes high-intensity maintenance, and induces better results with less training volume.",
author="Montoro-Bombú, Raynier
and Sarmento, Hugo
and Costa, Armando
and Pinheiro, Valter
and Malico Sousa, Paulo
and Buzzichelli, Carlo
and Rama, Luis",
pages="127--138",
doi="10.5114/biolsport.2026.152351",
url="http://dx.doi.org/10.5114/biolsport.2026.152351"
}