Effect of Muscle Action on the Kinetic and Kinematic Behavior of the Barbell during Isoinertial Strength Assessment

An isoinertial strength assessment was performed to examine the kinetic and kinematic behavior of barbell during several muscle actions. Velocity–time characteristics, force–time relationship, one repetition maximum (1RM), power output, acceleration were compared in eccentric–concentric (EC) versus concentric only (C) sequences bench press (BP) military (MP). In two separate sessions, 28 29 resistance-trained athletes executed EC or C random order BP MP, respectively, an incremental load test up their 1RM. Higher values recorded BP-EC than BP-C, MP-EC, MP-C (p < 0.01) for peak acceleration, rate force development, velocity output. Significant differences detected between exercises terms portion phase (%) at which detected, until observed 0.05). No where braking took place. The eccentric action prior movement a key factor enhance performance exercise. such effects countermovement produced MP.