New On-Water Test for the Assessment of Blood Lactate Response to Exercise in Elite Kayakers

PURPOSE: Lactate thresholds are physiological parameters used to train athletes and monitor performance or training. Currently, the assessment of lactate thresholds in kayakers is performed in a laboratory setting utilizing specific ergometers; however, laboratory tests differ from on-water evaluation for several reasons. The aim of this study was to assess reliability and validity of a new on-water incremental test for the assessment of blood lactate response to exercise in flat-water kayakers. Maximal lactate steady state test (MLSS) was used as criterion measurement. METHODS: Eleven junior (16.5±1.9yr) élite flat-water kayakers performed: i) an incremental cardiopulmonary test up to voluntary exhaustion on a stationary kayak ergometer to determine peak oxygen uptake; ii) an on-water 1000m distance trial (T1000) to record best performance time and average speed (S1000); iii) two repetitions of on-water incremental kayaking test (WIK-test); iv) several repetitions of on-water constant speed tests to determine MLSS. Speed, heart rate and blood lactate concentrations were determined during on-water tests. RESULTS: The best performance time in T1000 was 262±13s, corresponding to an S1000 of 3.82±0.19m·s. Lactate threshold determined by modified Dmax method (LTDmod) during WIK-test was 2.78±1.02mmol·L and the corresponding speed (SLT) was 3.34±0.16m·s. Test-retest reliability, calculated on SLT, was strong (ICC=0.95 and r=0.93). MLSS corresponded to 3.06±0.68mmol·L and was reached at a speed (SMLSS) of 3.36±0.14m·s. Correlation coefficient between SLT and SMLSS was 0.90 (p=0.0001). Interestingly, a significant correlation (r=0.96, p<0.0001) was observed between SLT and S1000. CONCLUSIONS: WIK-test showed good reliability and validity for the assessment of speed corresponding to LTDmod in flat-water kayakers and it could be a useful tool to monitor athletic performance. The speed value at LTDmod nicely predicted performance on 1000m.