To determine whether changes in strength or cardiorespiratory fitness after exercise training improve walking ability in individuals who have had a stroke.DESIGN
A sham exercise-controlled, randomized two-by-two factorial design, in which the two factors investigated were cycle training (AEROBIC) and resistance training (STRENGTH).SETTING
University exercise laboratory.PARTICIPANTS
Fifty-two individuals with a history of stroke (aged 63±9; time since stroke, 57±54 months).INTERVENTION
Participants undertook 30 exercise sessions over 10 to 12 weeks. Depending on group allocation, individuals underwent aerobic cycling plus sham progressive resistance training (PRT) (n=13), sham cycling plus PRT (n=13), aerobic cycling plus PRT (n=14), or sham cycling plus sham PRT (n=12).MEASUREMENTS
Primary outcomes were 6-minute walk distance, habitual and fast gait velocities, and stair climbing power. Secondary outcomes included measures of cardiorespiratory fitness; muscle strength, power, and endurance; and psychosocial attributes.RESULTS
Neither AEROBIC nor STRENGTH improved walking distance or gait velocity significantly more than sham exercise, although STRENGTH significantly improved participants' stair climbing power by 17% (P=.009), as well as their muscle strength, power, and endurance; cycling peak power output; and self-efficacy. Conversely, AEROBIC improved indicators of cardiorespiratory fitness only. Cycling plus PRT produced larger effects than either single modality for mobility and impairment outcomes.CONCLUSION
Single-modality exercises targeted at existing impairments do not optimally address the functional deficits of walking but do ameliorate the underlying impairments. The underlying cardiovascular and musculoskeletal impairments are significantly modifiable years after stroke with targeted robust exercise.