Relation Between Blood Lactate Levels, Heart Rate, And Rating Of Perceived Exertion In Kickboxing

Blood lactate has been shown to be a reliable tool to monitor the exercise intensity and fatigue level. However, heart rate (HR) seems to be more convenience and noninvasive index compared with blood lactate. PURPOSE To examine the relation between blood lactate levels (BL), HR, and rating of perceived exertion (RPE) in professional kickboxers during different periods of competition. METHODS 12 male and 11 female professional kickboxers (mean ± SD; age 20.1 ± 1.8 years; height 173.2 ± 5.9 cm; body mass 62.0 ± 1.5 kg) participated in this study. The BL, HR and RPE were measured before, during and after the match at national level competition. Subjects also performed incremental cycling test until exhaustion at which similar measurements were made. RESULTS There was a moderate correlation between BL and HR before, during and after the match, and the maximal relative coefficients were 0.87 (P<0.05) in male and 0.93 (P<0.05) in female. BL was highly correlated to HR during the last 3 rounds (P<0.05) during the match. Similar result was found in cycling trial. Whereas, the relation between BL and RPE was low, with the maximal relative coefficients were 0.37 in male and 0.33 in female (P>0.05). The relation between HR and RPE was also not significant. CONCLUSION The results reconfirmed that there is a close relationship between HR and BL during kickboxing. HR could be viewed as a valid tool to monitor the exercise intensity and fatigue level during the game.