Treadmill training improves fitness reserve in chronic stroke patients

Objective: To investigate the hypothesis that treadmill training will improve peak fitness, while lowering the energy cost of hemiparetic gait in chronic stroke patients. Design: Noncontrolled exercise intervention study with repeated-measures analysis. Setting: Hospital-based senior exercise research center. Participants: Twenty-three patients (mean age ± standard deviation [SD] 67 ± 8yr) with chronic hemiparetic gait after remote (>6mo) ischemic stroke. Intervention: Three 40-minute sessions of treadmill exercise weekly for 6 months. Main Outcome Measures: Peak exercise capacity (Vo₂peak) and rate of oxygen consumption during submaximal effort treadmill walking (economy of gait) by open circuit spirometry and ambulatory workload capacity before and after 3 and 6 months of training. Results: Patients who completed 3 months of training (n = 21) increased their Vo₂peak ± SD from 15.4 ± 2.9mL · kg^-1 · min^-1 to 17.0 ± 4.4mL · kg^-1 · min^-1 (p < .02) and lowered their oxygen demands of submaximal effort ambulation from 9.3 ± 2mL · kg^-1 · min^-1 to 7.9 ± 1.5mL · kg^-1 · min^-1(p = .002), which enabled them to perform the same constant-load treadmill task using 20% less of their peak exercise capacity (62.3% ± 17.2% vs 49.9% ± 19.3%, p < .002). Gains in Vo₂peak and economy of gait plateaued by 3 months, while peak ambulatory workload capacity progressively increased by 39% (p < .001) over 6 months. Conclusions: Treadmill training improves physiologic fitness reserve in chronic stroke patients by increasing Vo₂peak while lowering the energy cost of hemiparetic gait, and increases peak ambulatory workload capacity. These improvements may enhance functional mobility in chronic stroke patients.