Differentiated Perceived Exertion and Self-Regulated Wheelchair Exercise

Objective: To investigate the utility of the differentiated rating of perceived exertion (RPE) for the self-regulation of submaximal wheelchair propulsion in novice users. Design: Each participant completed a submaximal incremental test and a graded test to exhaustion to determine peak oxygen consumption (Vo(2peak)) on a wheelchair ergometer. On a separate day, two 12-minute intermittent bouts consisting of three 4-minute stages were completed at individualized imposed power outputs equating to light (40% Vo(2peak)) and moderate (60% Vo(2peak)) intensity exercise. On a third occasion, participants were assigned to either the overall group or the peripheral group and were required to self-regulate 12-minute intermittent exercise according to either overall RPE or peripheral RPE reported during the corresponding imposed intensity trial. Setting: Laboratory facilities at a university. Participants: Preliminary population of able-bodied participants with no prior experience of wheelchair propulsion (N=18). Interventions: Not applicable. Main Outcome Measures: Differences in oxygen consumption ((V) over doto(2)), heart rate, blood lactate concentration, and power output between the imposed and self-regulated exercise trials. Results: No difference was found in physiological responses between the moderate-intensity imposed and RPE-regulated trials in the peripheral group, whereas a significant (P<.05) underproduction in (V) over doto(2) (1.76 +/-.31 vs 1.59 +/-.25L/min) and blood lactate concentration (2.8 +/- 0.90 vs 2.21 +/-.83mmol/L) was seen in the overall group. In contrast, a significant (P<.05) overproduction was seen in the peripheral group at a light exercise intensity, whereas no difference was found between all variables during the light-intensity imposed and RPE-regulated trials in the overall group. Conclusions: Peripheral RPE enabled a more precise self-regulation during moderate-intensity wheelchair exercise in novice users. In contrast, overall RPE provided a more accurate stimulus when performing light-intensity propulsion. (C) 2013 by the American Congress of Rehabilitation Medicine