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 +/- 1.9 yr) elite 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 1000-m distance trial (T1000) to record best performance time and average speed (S-1000); iii) two repetitions of on-water incremental kayaking test (WIK test); iv) several repetitions of on-water constant speed tests to determine MLSS. Speed, HR, and blood lactate concentrations were determined during on-water tests. Results The best performance time in T1000 was 262 +/- 13 s, corresponding to an S-1000 of 3.82 +/- 0.19 m center dot s(-1). Lactate threshold determined by modified D-max method (LTDmod) during WIK test was 2.78 +/- 1.02 mmol center dot L-1 and the corresponding speed (S-LT) was 3.34 +/- 0.16 m center dot s(-1). Test-retest reliability, calculated on S-LT, was strong (ICC = 0.95 and r = 0.93). MLSS test corresponded to 3.06 +/- 0.68 mmol center dot L-1 and was reached at a speed (S-MLSS) of 3.36 +/- 0.14 m center dot s(-1). Correlation coefficient between S-LT and S-MLSS was 0.90 (P = 0.0001). Interestingly, a significant correlation (r = 0.96, P < 0.0001) was observed between S-LT and S-1000. Conclusions The 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 1000 m.