Using Ratings of Perceived Exertion to Reproduce Blood Lactate Levels During a Continuous Exercise Bout of Varying Intensities

The purpose of this study was to investigate whether blood lactate concentration (BLC) could be reproduced, corresponding to previously measured BLC, by using Borg’s rate of perceived exertion (RPE) scale to determine exercise intensity at 3 different levels during a single 30-min exercise bout. Twelve participants (4 M, 8 F; age: 26.5 ± 3.7 years; height: 168.9 ± 8.3 cm; weight: 68.2 ± 14.1 kg) completed an RPE estimation trial (a 3-min stage incremental treadmill protocol to volitional fatigue, where RPE was noted at each stage); practiced running at the workloads corresponding to their RPE of 11, 14, and 16; and, within 2 weeks after the practice run, completed a continuous, selfselected intensity run for 10-min at each RPE target value (the production run). Paired t tests indicated that there were no significant difference (p > .05) in BLC between the estimation and production trials at RPE of 11, 14, and 16 (estimation trial 2.71 ± 0.83, 4.15 ± 1.78, 5.83 ± 2.09 mM, production trial 2.99 ± 1.18, 4.32 ± 2.09, 5.62 ± 1.90 mM), indicating as a group that subjects were able to successfully reproduce target BLC. There was, however, considerable intraand inter-subject variability that warrants additional investigation before these results can be used to support RPE as a production tool for target BLC.