Training Status Modulates Perceptual Responses During Constant-Load Cycling at Maximal Metabolic Steady State.

Abstract

Although perceptual scales are widely used to prescribe endurance training, whether aerobic training status influences perceptual responses to heavy-intensity exercise remains unclear. Thus, this study investigated the effects of aerobic training status on perceptual responses during cycling performed at the maximal metabolic steady state (MMSS). Thirty-two participants (untrained, n = 18; trained, n =14) performed:1) step-ramp-step to determine maximal oxygen uptake (V̇O2max) and, 2) MMSS estimated intensity, followed by at least two 30 min constant workload rides to confirm the MMSS. The MMSS was defined as the highest exercise intensity at which oxygen uptake and blood lactate concentration were stable between the 15 th and 30 th min of exercise (change <120 mL·min -1 and <1 mmol·L -1, respectively). During the MMSS ride, rating of perceived exertion (RPE, 6-20), fatigue, leg pain, and dyspnea scales (0-10) were recorded at baseline and every 5 min until the end of exercise. V̇O2max (36.2 ± 6.6 mL·kg -1·min -1) and MMSS intensity (134 ± 40 W) were lower in untrained than trained group (V̇O2max: 54.0 ± 3.4 mL·kg -1·min -1; MMSS intensity: 209 ± 46 W) (p<0.001). Group×time interactions were observed for RPE (p≤0.001), fatigue (p=0.003), leg pain (p=0.009), and dyspnea (p=0.0018).Compared with the trained, the untrained group reported higher fatigue from 15 to 30 min (Δ= 2 a.u vs 1 a.u) and higher RPE (Δ= 2 a.u vs 1 a.u), leg pain (Δ= 2 a.u vs 1 a.u), and dyspnea from 20 to 30 min (Δ= 2 a.u vs 1 a.u) (post hoc p ≤0.04). Training status modulates the time course of perceptual drift at MMSS, with higher perceptual responses in untrained than trained individuals. Between-group differences emerged around 15 min, highlighting the importance of considering exercise duration when using perceptual scales to guide exercise at MMSS.