Intensive aerobic cycling training with lower limb weights in Chinese patients with chronic stroke: discordance between improved cardiovascular fitness and walking ability

Purpose: To evaluate the effect of aerobic cycling training with lower limb weights on cardiovascular fitness (peak VO2) and walking ability in chronic stroke survivors, and to investigate the relationship between changes in these parameters. Methods: 133 Chinese patients with chronic hemiparetic stroke (mean age 58 years) were randomized to either 8-week (5x/week) aerobic cycling training with lower limb weights group (n = 68) or a low-intensity overground walking group (n = 65). Peak VO2, 6-minute walk distance (6MWD), knee muscle strength, balance and spasticity were measured before and after intervention. Results: Cycling training increased peak VO2 (24% vs. 3%, p < 0.001), 6MWD (2.7% vs. 0.5%, p < 0.001), paretic (11% vs. 1.6%, p < 0.001) and nonparetic knee strength (16% vs. 1.0%, p < 0.001). In the cycling group, percent changes in peak VO2 were positively associated with those in paretic (r = 0.491, p < 0.001) and nonparetic knee strength (r = 0.432, p < 0.001). Increased 6MWD correlated significantly with improved balance, spasticity and paretic knee strength by the stepwise regression analysis (r(2) = 0.342, p = 0.004), but not fitness gains. Conclusions: The enhanced cardiovascular fitness after aerobic cycling training in Chinese patients with chronic stroke is not associated with the increased walking ability. Unparallel improvements in these parameters related different determinants may have implications for intervention strategy.