Effect of different inter-repetition rest intervals across four load intensities on velocity loss and blood lactate concentration during full squat exercise

Mora Custodio, RicardoRodríguez Rosell, DavidYáñez García, Juan ManuelMoreno-Sánchez, IsmaelPareja Blanco, FernandoGonzález Badillo, Juan José2025-02-192025-02-192018Mora-Custodio, R., Rodríguez-Rosell, D., Yáñez-García, J. M., Sánchez-Moreno, M., Pareja-Blanco, F., & González-Badillo, J. J. (2018). Effect of different inter-repetition rest intervals across four load intensities on velocity loss and blood lactate concentration during full squat exercise. Journal of sports sciences, 36(24), 2856–2864.10.1080/02640414.2018.1480052https://hdl.handle.net/10433/23227This study aimed to analyze the acute effect of inter-repetition rest (IRR) intervals on mechanical and metabolic response during four resistance exercise protocols (REPs). Thirty resistance-trained men were randomly assigned to: continuous repetitions (CR), 10 s (IRR10) or 20 s (IRR20) inter-repetition rest. The REPs consisted of 3 sets of 6, 5, 4 and 3 repetitions against 60, 70, 75 and 80% 1RM, respectively, in the full squat exercise. Muscle fatigue was assessed using: percentage of velocity loss over three sets, percentage of velocity loss against the ~1 m·s−1 load (V1 m·s−1), and loss of countermovement jump (CMJ) height pre-post exercise. Blood lactate was measured before and after exercise. The percentage of velocity loss over three sets and lactate concentration were significantly lower (P < 0.05) for IRR groups compared to CR in all REPs. The CR group showed a significantly higher (P < 0.05) velocity loss against V1 m·s−1 load and loss of CMJ height pre-post exercise than IRR groups in REP against 60% 1RM. In conclusion, both IRR groups produced a significant lower degree of fatigue compared to CR group. However, no significant differences were found in any measured variables between IRR configurations.application/pdfenAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/CIRFD Centro de Investigación en Rendimiento Físico y DeportivoResistance trainingCluster configurationsFatigueMetabolic stressEffect of different inter-repetition rest intervals across four load intensities on velocity loss and blood lactate concentration during full squat exercisejournal articleopen access