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 (Vo(2)peak) 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 Vo(2)peak +/- 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 Vo(2)peak 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 Vo(2)peak while lowering the energy cost of hemiparetic gait, and increases peak ambulatory workload capacity. These improvements may enhance functional mobility in chronic stroke patients.