A unique method for predicting cardiorespiratory fitness using rating of perceived exertion

The purpose of this study was to develop a simple and convenient indirect method for estimating maximal oxygen uptake (VO2max) and oxygen uptake at the anaerobic threshold (VO2AT) by using workrate and a rating of perceived exertion (RPE) during a submaximal graded cycling test (GCTsubmax). One hundred and fifty-four healthy Japanese men, aged 20 to 64 years, volunteered to participate in the study. The subjects were randomly divided into two groups, a validation (V) group (n = 100) and a cross-validation (CV) group (n = 54). The V and CV groups performed a maximal cycling test and the GCTsubmax. The GCTsubmax was conducted with documentation of three categories (overall, chest, legs) of RPE, up to a rating of 15. Prediction equations of VO2max and VO2AT were developed by multiple regression analysis using data of the V group. The mean VO2max and VO2AT of the V group were 2462 +/- 484 ml.min-1 and 1349 +/- 334 ml.min-1, respectively. Correlational analyses indicated that the workrate (W) at which the legs RPE (RPElegs) reached 15 or higher was evaluated first (WRPE legs 15) together with WRPE legs 14 both yielded the highest correlation coefficients (r) with VO2max (r = 0.781) and V O2AT (r = 0.790), respectively. The developed prediction equations of VO2max and VO2AT were VO2max (ml.min-1) = 1.19 WRPE legs 15 (kgm.min-1) - 15.84 age (yr) + 13.06 weight (kg) + 1365 (R = 0.849, SEE = 261 ml.min-1) VO2AT (ml.min-1) = 1.34 WRPE legs 14 (kgm.min-1) - 5.49 age (yr) + 665 (R = 0.816, SEE = 195 ml.min-1) Results of a cross-validation analysis indicated a similar estimation (r = 0.793 and 0.853, and SEE = 240 ml.min-1 and 183 ml.min-1) compared with the above equations developed from data of the V group. Reliability coefficients of V O2max (r = 0.891) and VO2AT (r = 0.870) respectively were significant and there was no difference in the mean value between trials 1 and 2. The "RPE method" developed for estimating cardiorespiratory fitness is not only a unique indirect method but also a valid and useful tool in various settings of exercise prescription.