An 8-week Forced-rate Aerobic Cycling Program Improves Cardiorespiratory Fitness in Persons With Chronic Stroke: A Randomized Controlled Trial

Abstract

ObjectiveTo examine the cardiorespiratory effects of a forced-rate aerobic exercise (FE) intervention among individuals with chronic stroke compared with an upper extremity repetitive task practice (UE RTP) control group. DesignSecondary analysis of data from a randomized controlled trial. SettingResearch laboratory. ParticipantsIndividuals with chronic stroke (N=60). InterventionsParticipants completed 24 sessions of FE followed by RTP (FE+RTP, N=30) or time matched RTP alone (N=30). The FE+RTP group was prescribed exercise at 60%-80% of heart rate reserve on a motorized stationary cycle ergometer for 45 minutes followed by 45 minutes of RTP. The control group completed 90 minutes of RTP. Main Outcome MeasuresMetabolic exercise stress tests on a cycle ergometer were conducted at baseline and post-intervention. Outcomes included peak oxygen consumption (peak V̇o2) and anaerobic threshold (AT). ResultsFifty participants completed the study intervention and pre/post stress tests. The FE+RTP group demonstrated significantly greater improvements in peak V̇o2 from 16.4±5.7 to 18.3±6.4 mL/min/kg compared with the RTP group (17.0±5.6 to 17.2±5.6 mL/min/kg, P=.020) and significantly greater improvements in AT from 10.3±2.8 to 11.5±3.6 mL/min/kg compared with the RTP group (10.8±3.9 to 10.4±3.2 mL/min/kg, P=.020). In analyzing predictors of post-intervention peak V̇o2, the multivariable linear regression model did not reveal a significant effect of age, sex, body mass index, or beta blocker usage. Similarly, bivariate linear regression models for the FE group only did not find any exercise variables (aerobic intensity, power, or cycling cadence) to be significant predictors of peak V̇o2. ConclusionsWhile the aerobic exercise intervention was integrated into rehabilitation to improve UE motor recovery, it was also effective in eliciting significant and meaningful improvements in cardiorespiratory fitness. This novel rehabilitation model may be an effective approach to improve motor and cardiorespiratory function in persons recovering from stroke.