Ratings Of Perceived Exertion And The Blood Lactate Response To Exercise

Abstract

PURPOSE To examine the relationship between the Borg Scale (6–20) and the OMNI-Walk/Run Scale (0–10) ratings of perceived exertion (RPE) associated with the lactate threshold (LT), blood lactate concentrations (BLC) of 2.5 and 4.0 mM, and peak. METHODS Four males and seven females diagnosed with the metabolic syndrome [(mean ± SEM) age: 40.8 ± 5.17 y, height: 156.7 ± 15.8 cm, weight: 99.3 ± 11.9 kg, body mass index (BMI): 36.6 ± 2.1 kg·m−2] completed a continuous peak oxygen consumption (VO2 peak)/LT treadmill protocol. The initial treadmill velocity was 60 m min−1, and velocity was increased by 10 m min−1 every 3 minutes until volitional fatigue. VO2 (ml·kg−1·min−1), blood lactate concentration (mM), heart rate (beats·min−1), and treadmill velocity (m·min−1) were assessed at the end of each stage. RPE were assessed at 2:15 and 2:45 of each stage using both the Borg Scale and the OMNI-Walk/Run Scale presented to the subject in a counter-balanced order. Prior to testing, each participant was read a set of standardized instructions specific to each perceptual scale. The LT and BLC of 2.5 and 4.0 mM were determined from the lactate-velocity relationship. RESULTS Results are presented below as the means ± SEM. Analysis of Variance (ANOVA) with repeated measures (RM) revealed that there were significant condition effects observed for each parameter examined (all p-values <0.001) [N = 8 (3 subjects insufficient lactate data)]. Borg and OMNI-RPE were positively correlated across all exercise intensities [r = 0.94, p <.001 (N=11)]. The error associated with estimating the mean perceptual response (e.g. ± 2 sd/mean) at the LT, BLC of 2.5 and 4.0 mM, and peak ranged from 10.5% - 34.0% and 19–88% using the Borg and OMNI Scales, respectively.Table 1: Mean responses to the VO2 peak/LT protocolCONCLUSIONS Both the Borg and OMNI Scales demonstrate predictive utility as markers of the blood lactate response to acute exercise. However, the present data suggest that RPE obtained by the Borg Scale may be a superior discriminator of the blood lactate response to exercise. Supported by a NIH grant to the GCRC RR00847, and NIH:NCCAM grants T32AT00052 and K30AT00060.