REPEATED BOUTS OF EXERCISE ALTER THE BLOOD LACTATE ([HLa])-RATINGS OF PERCEIVED EXERTION (RPE) RELATIONSHIP 1231

We examined the effects of repeated bouts of exercise on the blood[HLa]-RPE relationship. Six moderately trained males were studied on 2 occasions: a sequential exercise day (SEB: 1000h, 1130h, 1300h) and a delayed exercise day (DEB: 1000h, 1400h, 1600h). Each exercise bout was 30 min at the power output (PO) associated with 70% VO2 Peak on a cycle ergometer. A standardized meal was provided at 0600h. Metabolic parameters were collected continuously and blood [HLa] and RPE were measured every 5 min during exercise. Results [mean (SEM)] are presented below:Table A 2 × 3 repeated measures ANOVA revealed that blood [HLa] decreased significantly with each repeated bout (P<0.05). RPE-Legs was higher during bout 3 compared to bout 1 (P<0.05). RPE-Chest was not affected by repeated bouts of exercise, whereas RPE-Overall was higher during bout 3 compared to bouts 1 and 2 (P<0.05). VO2, PO/min and Kcal/min were not affected by repeated bouts of exercise. No interaction was observed between SEB and DEB for any variable. We conclude that the blood [HLa]-RPE relationship is altered by repeated bouts of exercise and that RPE should not be used for exercise prescription to produce a specific blood [HLa] on subsequent exercise bouts.