An a-posteriori multicentre reliability study was conducted to compare the reliability and magnitude of the maximum power (P-max) and optimal velocity (V-opt) between the force-power-velocity relationships during the leg cycle-ergometer and bench press throw exercises. The force-power-velocity relationships were determined in two separate sessions considering the values of force, velocity, and power collected under multiple loads. The force-velocity relationship was also determined from the force and velocity values collected under only the two most distant loads. Reliability of all regression models was high for P-max and V-opt during the leg cycle-ergometer (CVrange: 1.73-2.98%) and for P-max during the bench press throw (CVrange: 4.47-4.73%), while the reliability was acceptable for V-opt during the bench press throw (CVrange: 6.52-7.34%). Significant differences between the force-power-velocity relationships were observed for both P-max and V-opt (P < .001). All regression models can be confidently used to determine P-max and V-opt, but these should not be used interchangeably.