THE EFFECT OF TRAINING INTENSITY ON RATINGS OF PERCEIVED EXERTION

We examined the effects of intensity of training on ratings of perceived exertion (RPE) at the lactate threshold (LT), fixed blood lactate concentrations (FBLC) of 2.0, 2.5 and 4.0 mM and peak in 25 untrained eumenorrheic women (xBAR +/- SD: age = 30.9 +/- 4.1 yrs; height = 165.7 +/- 5.9 cm; weight = 65.5 +/- 7.6 kg) who completed one year of run training. Subjects were recruited as sedentary controls or were randomly assigned to one of two training groups: 1) at the lactate threshold (@LT) or 2) above the lactate threshold (> LT). The @LT group trained at velocity LT and the > LT group trained at the velocity midway between velocity LT and peak velocity. Training subjects were reevaluated every fourth menstrual cycle and training intensity was adjusted. The control group was reassessed at menstrual cycle 12. Before training no among group differences were observed for VO2 or velocity at LT, FBLC and peak. Both training groups increased VO2 at LT, FBLC and peak as a result of training (p < 0.05), with the > LT group exhibiting greater improvement than the @LT group (VO2 at LT, FBLC of 2.0, 2.5 and 4.0 mM and peak increased by 6.4, 5.3, 5.1, 4.0 and 4.7 ml/kg.min-1 for @LT and by 10.4, 9.2, 8.6, 5.1 and 5.9 ml/kg.min-1 for > LT; p < 0.05). Similar findings were observed for the velocity associated with these lactate concentrations. No pre/post differences were observed in VO2 or velocity for the control group. In spite of the differential training response, RPE remained stable at LT and FBLC of 2.0, 2.5 and 4.0 mM and peak (xBAR RPE = 12.3, 14.7, 15.8, 17.6 and 19.3, respectively). We conclude that RPE remains stable at LT, FBLC and peak independent of changes in fitness or training intensity. Therefore, if blood lactate concentrations are used for exercise prescription, RPE may provide a suitable means for regulating training intensity.