Author(s): FONTANETTI, G., CAMPOS, P. H. A., LIMA, L. C. R., Institution: SÃO PAULO STATE UNIVERSITY INSTITUTE OF BIOSCIENCES, Country: BRAZIL, Abstract-ID: 1262

INTRODUCTION:
One of the applications of the post-activation performance enhancement (PAPE) phenomenon is contrast training sessions (CNT). However, since CNT involves the repetition of multiple cycles of conditioning activities (CA) followed by explosive exercises, the potentiating effect of CA may not be sustained throughout the session. It is still poorly understood PAPE is manifested temporally within each cycle, especially regarding the total magnitude of the effect produced, since most studies are based on discrete time-point comparisons. Thus, the objective of this study was to analyze the kinetics of PAPE over four CA cycles using integrative metrics of countermovement jump (CMJ) performance.
METHODS:
Twelve strength-trained individuals (6 men and 6 women: 25.2 ± 6.5 years; 69.6 ± 14.6 kg; 170 ± 0.1 cm) participated in two randomized sessions after familiarization and 1RM testing (155 ± 43 kg). The experimental session (EXP) consisted of four cycles of CA (3x3 squats with 87% of 1RM) followed by CMJ assessments every two minutes until minute 10. In the control session (CON), CA was replaced by rest. Baseline CMJ was assessed in both sessions after a light warm-up.
The area under the curve relative to the increment (AUCi) of CMJ performance was calculated relative to baseline values using the trapezoidal method and compared between sessions and cycles using two-way ANOVA for repeated measures. The external training load was quantified by the Plyometric Stress Index (PSI) and compared between sessions by paired t-test, with a significance level of p<0.05.
RESULTS:
ANOVA revealed significant session, cycle, and session-cycle interaction effects. AUCi was higher in the EXP session compared to the CON session in cycles 1 (24.42 ± 10.23 cm·min vs. -2.07 ± 3.69 cm·min; p<0.001) and 2 (6.82 ± 13.72 cm·min vs. -5.49 ± 7.47 cm·min; p<0.05), with no differences (p>0.05) in cycles 3 (-11.01 ± 13.17 cm·min vs. -12.45 ± 16.06 cm·min) and 4 (-19.09 ± 14.26 cm·min vs. -15.77 ± 17.64 cm·min). In the CON session, there were no differences in AUCi between cycles. In the EXP session, AUCi differed between all cycles (p<0.05). Furthermore, PSI was higher in the EXP session compared to CON (48926.46 ± 16502.29 kg·cm vs. 47032.46 ± 15292.29 kg·cm; p<0.05), with an average individual percentage variation of 3.79%.
CONCLUSION:
The results indicate that CNT is effective in improving CMJ performance, but in a transient and cycle-dependent manner. AUCi demonstrated greater responses in cycles 1 and 2 of the EXP session, with a loss of effect on the final cycles, while the higher PSI in the EXP session indicates a greater accumulated external load compared to CON. Together, these findings demonstrate that PAPE manifests only in the initial cycles of the session and that this early potentiation is sufficient to increase the total accumulated load, even in the absence of sustained performance enhancement in later cycles.