Abstract:
Recommendations for use of the Borg rating of perceived exertion scale (RPE) during graded exercise testing (GXT) vary from inquiries made once per exercise stage to once per minute. However, previous studies assessing the reliability of the scale during GXTs suggest inquiry frequency can influence RPEs at submaximal exercise levels. The purpose of this study was to further examine the effect of inquiry frequency on RPEs during GXT on a treadmill (TM). Fifteen young men and women were randomly assigned to completed two GXTs within 48 hours using the Bruce protocol. RPE queries were made either once per stage (RPE:STAGE) or once per minute (RPE:MINUTE). Heart rate (HR), oxygen uptake (VO2), minute ventilation (VE) and respiratory exchangeratio (RER) were compared across GXTs at the end of each submaximal stage and peak exercise using repeated-measures ANOVA.STAGE ISTAGE IISTAGE IIIRPE:MINRPE:STAGERPE:MINRPE:STAGERPE:MINRPE:STAGEHR(bpm)113.0±10.0111.0±10.0137.0±11.0136.0±12.0171.0±12.0171.0±12.0VO,(ml/kg/min)16.3±2.416.2±2.223.9±3.422.8±2.033.8±2.033.6±3.6RPE8.9±1.7*7.9±1.212.7±1.5*10.8±1.716.1±2.5*14.7±2.7RER0.79±0.060.77±0.050.91±0.080.88±0.061.08±0.111.09±0.11VE (L/min)26.13±6.325.6±5.038.1±6.036.7±5.267.2±11.164.7±8.4*p<.05No differences were observed between the GXTs for any physiological measures during submaximal or peak exercise. Peak RPEs were not different between the GXTs (19.1 ± 0.9 vs. 19.0 ± 0.7). However, RPEs were significantly higher (p< 0.01) at each submaximal stage during the GXTs. Oxygen uptakes at stages I, II and III represented 40, 58 and 81 percent of VO2 peak, respectively, so these results apply to the typicalexercise training intensity range. These data confirm that inquiry frequency can significantly influence submaximal RPE responses during GXTs; and therefore, RPE inquiry methods should be standardized when data are collected for serial comparative purposes or when using RPE data from a GXT to establish a target RPE for training.