Rodrigues B, Maior AS, Sakugawa R, Bezerra E. Acute Effects of Fixed Rest Time during Multiple Sets on Upper Limbs Performance. JEPonline 2018;21(3):86-93. This study analyzed the acute effects of a 2-min rest interval on range of motion (ROM), blood lactate, and myoelectric activation (sEMG). Ten healthy resistance-trained men participated in the experimental protocol. Previously, they performed test and retest of 10RM (repetition maximum) on bench press (BP). After 48 hrs, the myoelectric activation on upper trunk and arm muscles; ROM elbow flexion; and blood lactate level were monitored before, during, and after 3 sets of BP with a 2-min rest interval between sets. Triceps brachii sEMG showed a decrease in set 2 and set 3 when compared to set 1 (P<0.05). Rectus abdominis sEMG increased in set 3 when compared to sets 1 and 2 (P<0.05). There were no significant differences on myoelectric activity for the pectoralis major and anterior deltoid between sets (P>0.05) and phases (P>0.05), respectively. Elbow flexion showed a higher ROM during set 1 when compared to sets 2 and 3 (P<0.05). Elbow extension showed no significant difference between sets (P>0.05). Blood lactate showed increase over the periods (set 3> set 2> set 1> rest, P<0.05). Absolute load volume was lower in set 3 in relation to set 2 and set 1 (P<0.05). We conclude that the fixed interval of 2 min is not sufficient to control for reduction in performance during bench press with load of 10RM. Thus, we suggest a rest time >2 min for better performance in this specific exercise for multiple sets. Key Words: Electromyography, Kinematic, Resistance Training