The role of stretch-shortening cycle and sex in subsequent jump tasks improvement after conditioning activity based on holding isometric muscle action.

Abstract

Background: This study aimed to elucidate the effectiveness of holding isometric muscle action (HIMA) by examining its impact on vertical jump enhancement due to sex and the presence of the stretch-shortening cycle (SSC) in subsequent jump tasks.

Methods: The sample was 63 men and 42 women aged 20-27, engaged in continuous strength training for over two years at least, without musculoskeletal injuries in the past six months, divided into experimental (EXP) and control (CON) groups for countermovement jump (CMJ) and squat jump (SQ) tests considering sex. Conditioning activity (CA) involved three sets of four seconds of full-back squats at 70% 1RM for the experimental group. Jump heights for CMJ and SJ were measured, and absolute (baseline-best) and relative (%) changes were analyzed. For statistical analysis were made with Three-Way ANOVA and Tukey-Kramer post-hoc tests to evaluate jump performance differences.

Results: EXP achieved more gains than control in SQ for both sexes, and both measurement approaches (P<0.05), yet no sex differences in gains were found (P>0.05). Absolute CMJ improvements were significant in experimental men versus control (P<0.05), but relative gains were not (P>0.05). SSC presence did not differentiate SQ and CMJ improvements according to sex (P>0.05); however, the effect size was large <0.80.

Conclusions: The utility of HIMA protocol as a CA has proven to be effective in improving jump performance despite sex or SSC involvement in subsequent tasks. This study showcases the adaptability of the PAPE protocol based on isometric full-back squats with submaximal load, confirming its effectiveness in enhancing jump performance in various settings.