Reproducibility of blood lactate-anchored ratings of perceived exertion

Abstract

This study investigated the reproducibility of blood lactate-anchored ratings of perceived exertion (RPE) in seven women of average, and seven of above average cardiorespiratory fitness, [moderate and high maximal oxygen uptake (Mod and High , respectively)]. The subjects completed a series of four exercise tests, comprising a assessment and three 0-grade, velocity-incremental, treadmill-running RPE estimation trials. The results revealed no significant between-group differences in RPE at the blood lactate concentration threshold (LT), and at reference levels of 2 , 2.5 or 4 mmol·l–1 (RPELT, RPE2, RPE2.5 and RPE4, respectively). The RPELT, RPE2, RPE2.5 and RPE4 were characterised by intra-class correlation coefficients of 0.97, 0.97, 0.97, 0.72 and 0.83, 0.96, 0.96, 0.90, in the High and Mod groups, respectively. The SEM% (95% confidence limits computed as a percentage of the group mean score) largely mirrored the trend in reliability with the highest values observed for RPELT in the Mod group and RPE4 in the High group. The Spearman-Brown prediction equation indicated that fixed blood lactate concentrations of 2, 2.5 and 4 mmol·l–1 offer acceptable practical utility as potential perceptual anchor points for both groups, requiring one trial only to achieve a measurement error of less than ±6%.