García-Ramos, A, González-Hernández, JM, Baños-Pelegrín, E, Castaño-Zambudio, A, Capelo-Ramírez, F, Boullosa, D, Haff, GG, and Jiménez-Reyes, P. Mechanical and metabolic responses to traditional and cluster set configurations in the bench press exercise. J Strength Cond Res XX(X): 000–000, 2017—This study aimed to compare mechanical and metabolic responses between traditional (TR) and cluster (CL) set configurations in the bench press exercise. In a counterbalanced randomized order, 10 men were tested with the following protocols (sets × repetitions [inter-repetition rest]): TR1: 3 × 10 (0-second), TR2: 6 × 5 (0-second), CL5: 3 × 10 (5-second), CL10: 3 × 10 (10-second), and CL15: 3 × 10 (15-second). The number of repetitions (30), interset rest (5 minutes), and resistance applied (10 repetition maximum) were the same for all set configurations. Movement velocity and blood lactate concentration were used to assess the mechanical and metabolic responses, respectively. The comparison of the first and last set of the training session revealed a significant decrease in movement velocity for TR1 (Effect size [ES]: −0.92), CL10 (ES: −0.85), and CL15 (ES: −1.08) (but not for TR2 [ES: −0.38] and CL5 [ES: −0.37]); while blood lactate concentration was significantly increased for TR1 (ES: 1.11), TR2 (ES: 0.90), and CL5 (ES: 1.12) (but not for CL10 [ES: 0.03] and CL15 [ES: −0.43]). Based on velocity loss, set configurations were ranked as follows: TR1 (−39.3 ± 7.3%) > CL5 (−20.2 ± 14.7%) > CL10 (−12.9 ± 4.9%), TR2 (−10.3 ± 5.3%), and CL15 (−10.0 ± 2.3%). The set configurations were ranked as follows based on the lactate concentration: TR1 (7.9 ± 1.1 mmol·L−1) > CL5 (5.8 ± 0.9 mmol·L−1) > TR2 (4.2 ± 0.7 mmol·L−1) > CL10 (3.5 ± 0.4 mmol·L−1) and CL15 (3.4 ± 0.7 mmol·L−1). These results support the use of TR2, CL10, and CL15 for the maintenance of high mechanical outputs, while CL10 and CL15 produce less metabolic stress than TR2.