For high-velocity running or swimming, the relationship between velocity (v) and its sustainable duration (t) can be described by a hyperbolic relationship: (v - V_crit)·t = D’, where V_crit is termed critical velocity, and D’ is defined as a curvature constant of the hyperbolic curve. The purposes of this study were to examine whether the V_crit could be applied to evaluate short-distance breaststroke swimming performance and to evaluate the relative contribution of D’ in short-distance swimming performance. Eleven male swimmers performed a series of time trials corresponding to 75, 100, and 150-m in an indoor 50-m swimming pool. The observed records were calculated into average velocities of each event to determine V_crit and D’. After the determination of V_crit and D’, all subjects performed 50-m time trial on another day. A maximal anaerobic power test using cycle ergometer was also performed in the laboratory. The average velocity of the 50-m time trial significantly correlated with the obtained V_crit, but not with D’. D’ was significantly correlated with the residual error, calculated from the regression analysis for the relationship between V_crit and the average velocities of 50-m time trial. A cluster analysis showed that most of the subjects were classified as V_crit dependency when performing 50-m time trial. Those results indicated that V_crit could be applied to evaluate short-distance swimming performance, and it determined around 80% of the short-distance breaststroke swimming performance.

• For high-velocity running or swimming, the relationship between velocity (v) and its sustainable duration (t) can be described by a hyperbolic relationship: (v - V)·t = D’, where V is termed critical velocity, and D’ is defined as a curvature constant of the hyperbolic curve. The D’ contributed only around 20% of the breaststroke swimming performance even in a short-distance event.

• Critical velocity determined around 80% of 50-m breaststroke swimming performance, and it could be a useful tool for evaluating short-distance swimming performance.

• Most of the swimmers showed characteristics for critical velocity dependent physical fitness even in short-distance swimming event.