Comparison between perceived exertion threshold and indicators of maximal lactate steady state in intermittent exercise

Abstract

The continuous perceived exertion threshold (PETc) is considered as a metabolic transition point between the heavy and severe domain, since it is related with critical power. Thus, the aims of this study were: (1) to verify the possibility to estimate PET and maximal lactate steady state index in intermittent exercises (PETi and MLSSINDEX), (2) compare the PETi and MLSSINDEX with intermittent exercise maximal lactate steady state (MLSSi), and (3) to verify the relationship between RPE and blood lactate response ([La]) in high intensity intermittent exercises. Ten subjects underwent familiarization sessions, progressive exercise test, predictive intermittent trials and MLSSi determination. The PETi and MLSSINDIC were estimated from predictive trials, and MLSSi was determined from 30-minute tests. The correlations between the increase rates of RPE and [La] (r=0.77), and the absolute values of RPE and [La] (r=0.78) were moderate. The high R2 values as related to the relationship between the increase rate of RPE and [La], and also to the linear regressions for the PETi and MLSSINDEX estimation suggest that these variables may be accurately estimated. The PETi, MLSSINDEX and MLSSi intensities were not different from each other. The correlations between PETi and MLSSINDEX, with MLSSi were strong (r=0.90 and r=0.80, respectively). Therefore, the relationship between RPE and [La] is moderate, while both PETi and MLSSINDEX can be estimated and utilized as aerobic capacity indicators.