Critical velocity in swimmers of different ages

BACKGROUND: In swimming one of the most employed training speed among coaches is the non-invasive theoretical critical velocity (TCV) defined as the velocity that can be maintained continuously without exhaustion. METHODS: We calculated the 4 mmol/L lactate critical velocity (MCV) in a group of swimmers of different ages (young, elite and master), and compared results to the predicted TCV defined starting from the 200 and 400 m freestyle best seasonal performances. A steady-state test consisted in 20 repetitions of 100 m each was performed to study the effect of the imposed MCV in the three athletes' categories. RESULTS: TCV mean values resulted slightly higher than MCV mean values. A strong correlation between TCV and MCV was found considering the whole sample (r=0.96. P<0.001). the Masters (r=0.97. P<0.001) and the Elite (r=0.93 P<0.01). Lactate concentration of the three groups after the steady-state test was 4.2 mmol/L, 3.3 mmol/L and 4.9 mmol/L respectively for young, elite and master groups. CONCLUSIONS: TCV is a reliable, practical and quick parameter that well approximate the anaerobic threshold pace. MCV underestimated the fixed 4 mmol/L lactate threshold pace in the elite swimmers and overestimate it in the master swimmers. Further investigation is needed to understand more in detail TCV applicability for athletes of different ages.