Acute responses and chronic adaptations to cluster versus traditional set resistance training in males and females

This study compared acute and chronic adaptations to cluster set (CS) and traditional set (TS) structures during a 6-week linear periodised resistance training programme in the back squat. Thirty-six resistance-trained females and males were randomly assigned to the CS or the TS group. Acute responses were assessed using objective (blood lactate, mean propulsive velocity, velocity loss [VL], countermovement jump [CMJ] height and modified reactive strength index) and subjective measures (rating of perceived exertion [RPE], delayed onset muscle soreness and the short recovery and stress scale). Chronic adaptations included one-repetition maximum (1RM), relative isometric peak force, muscle endurance, CMJ height, velocity at 70% 1RM (v70) and load–velocity (L–V) profiling. CS displayed higher barbell velocities and lower acute fatigue, reflected by VL (g = −0.56 to −2.16), lactate (g = −0.51 to −1.86) and RPE (g = −0.91). TS did not demonstrate lower fatigue in any acute measure. Both protocols elicited comparable improvements in 1RM (CS: g = 0.28; TS: g = 0.23), muscle endurance (CS: g = 0.48; TS: g = 0.50) and v70 (CS: g = 1.18; TS: g = 1.32), with no significant improvements in CMJ height or isometric peak force. Post-intervention L–V profiling revealed distinct adaptations, with CS demonstrating a shallower slope, indicating higher velocities at heavier loads. Sex differences were minimal; females displayed lower lactate and RPE, while longitudinal adaptations were similar. In conclusion, both protocols improved muscle strength and endurance. Collectively, CS provided superior fatigue management, better preservation of barbell velocity and unique L–V profile adaptations.