Perceived Exertion And Met-defined Intensity During Treadmill Exercise In College-age Adults

BACKGROUND: The Borg scale (6-20) captures individuals’ rating of perceived exertion (RPE) during exercise, while the oxygen cost (intensity) of exercise is measured using indirect calorimetry as multiples of metabolic equivalents (METs: 1 MET = 3.5 ml/kg/min). This study explores the relationship between RPE and METs during walking/running in college-age adults 18-20 years of age. METHODS: Seventy-two participants (mean age = 19.0, SD 0.8 years; mean BMI = 23.92, SD 4.71; 51.38% female) performed incremental treadmill exercise (0.5mph - 6.0mph), with oxygen uptake (VO2) measured by indirect calorimetry. MET values were calculated per 5-minute bout. Borg RPE was solicited during the final 30 seconds of each bout. A linear mixed effects model with a spline component and both random intercepts and slopes for participants was used to estimate the association between RPE and MET, and a 95% confidence interval was computed. RESULTS: Descriptive statistics show a mean RPE of 10.26 (SD 2.84) and mean MET of 5.69 (SD 3.02), with participants completing a mean of 9.33 bouts (SD 2.30), contributing to a total of 672 bouts across all 72 participants. There was a significant nonlinear relationship between RPE and METs (p < 0.0001). MET values increased with higher RPE. For example, at RPE = 6, the expected MET was 1.86 (95% CI: 1.39, 2.34), and at RPE = 17, it was 13.90 (95% CI:12.60, 15.20). CONCLUSIONS: The Borg RPE scale is associated with oxygen cost across walking/running in college-age adults. While this study provides a 95% confidence interval for the mean MET levels associated with specific RPE values, further research is needed to confirm these findings in other populations. Supported by: NIH NICHD - R01HD105768