Pasquale Succi: Sex-and Intensity-Specific Responses During Cycle Ergometry Anchored to Ratings of Perceived Exertion

Succi, Pasquale Sex- and Intensity-Specific Responses during Cycle Ergometry Anchored to Ratings of Perceived Exertion Abstract The traditional paradigm used to examine the responses to cardiorespiratory endurance (CE) exercise is based on constant velocity or power output (PO) exercise. However, when exercise is anchored by a physiological or perceptual parameter, those typical responses become dissociated. Thus, it is difficult to accurately prescribe exercise for improvements in cardiorespiratory fitness (CRF) when the potential stimuli of anchoring exercise via physiological or perceptual parameters, such as heart rate (HR) or rating of perceived exertion (RPE), is unclear. Specifically, it has been recommended for moderately and highly trained individuals that exercise anchored at RPE should range from RPE 14 to RPE 17 for continuous endurance bouts. While the responses to constant RPE exercise have been examined at other intensities, the responses to exercise anchored at the RPE range used for CRF training has not been investigated. Therefore, the purpose of this study is to examine the time to exhaustion (TLim), metabolic (volume of oxygen consumption [V? O2], HR, respiration rate [RR]), muscle oxygen saturation (%SmO2) and neuromuscular (electromyographic [EMG] and mechanomyographic [MMG] amplitude [AMP] and mean power frequency [MPF]) responses to exercise anchored to the RPE range used for endurance exercise prescription. Ten men and ten women who are moderately trained will, on separate days, complete a graded exercise test (GXT), and trials to exhaustion with RPE anchored to RPE 14 and RPE 17. The metabolic responses will be measured via a metabolic cart which will record the V? O2, V? O2/PO (Eff), HR, and RR. Performance measures including TLim and changes in PO will be recorded during all trials. In addition, performance fatigability will be assessed via a maximal voluntary isometric contraction (MVIC) before and immediately after each trial. During all visits, a bipolar surface EMG electrode arrangement and an MMG accelerometer will be placed on the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) of the right limb. Muscle oxygen saturation will be measured at the VL of both limbs also during all visits. Statistical analyses will include separate 2 (sex [men, women]) x 2 (condition [RPE 14, RPE 17]) x 10 (%TLim [0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100%]) mixed model (MM) analyses of variance (ANOVAs) to examine the changes in V? O2, HR, RR, %SmO2, and PO during the constant RPE trials with appropriate follow-up two- and one-way ANOVAs. In addition, separate 2 (sex [men, women]) x 2 (condition [RPE 14, RPE 17]) x 3 (muscle [VL, VM, and RF]) x 10 (%time to exhaustion [0-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100%]) MM ANOVAs will be used to examine the changes in EMG and MMG AMP and MPF during the constant RPE trials with appropriate follow-up three-, two- and one-way ANOVAs. Changes in performance fatigability (%? from pre- to post-exercise) will be examined with separate 2 (sex [men, women]) x 2 (condition [RPE 14, RPE 17]) MM ANOVAs with appropriate follow-up one-way ANOVAs. Post-hoc Student Newman-Keuls tests will then be used to examine the time course of changes among the repeated measures variables. The alpha level will be set at p ? 0.05. The goal of this study is to examine the stimuli underlying the variability in cycling performance during endurance exercise anchored to the recommended range of RPE for CE training. Keywords: Cycling; Cardiorespiratory Fitness; Rating of Perceived Exertion