The aim of this paper was to review the origin of the critical speed (CS) concept and how it may be applied to swimming. Regarding the physiological significance, substantial increases in some physiological markers (blood lactate, oxygen consumption and heart rate) were observed in rectangular intensity efforts during the CS, suggesting that this is above the anaerobic threshold and the maximal steady state lactate. Factors influencing CS are thought to include (1) using different combinations of distances used in the test to determine CS, (2) age of the individual, and (3) the swimmer's level of experience. It can be concluded that the CS represents an adequate tool for controlling training intensity and has the benefit of being comparatively simple to measure in relation to others forms of control. However, use of CS as a tool for predicting performance in swimming still needs further investigation.
Critical speed; Swimming; Performance
