Purpose: This study investigated the effects of high-intensity progressive resistance training (PRT) and high-intensity cycling (cycling) on muscle performance and the time course of strength gains in a chronic stroke population.
Methods: Forty-eight individuals with chronic stroke sequelae (mean +/- SD; age = 63 +/- 9 yr, time since stroke = 57 +/- 54 months) were randomly allocated to one of four treatment groups: PRT + cycling, PRT + sham cycling, sham PRT + cycling, or sham PRT + sham cycling groups in a fully factorial clinical trial. Thirty exercise sessions were conducted over a 10- to 12-wk period. The main outcomes investigated were measures of unilateral muscle strength, peak power, and muscle endurance.
Results: Those undergoing PRT improved their lower limb muscle strength, peak power, and endurance compared with participants receiving sham PRT or cycling only (P < 0.05), and combined exercise was not superior to PRT alone. Strength improvements occurred primarily during the first 6 to 8 wk (98%-100% of total gain) and then reached a plateau during the final 2 to 4 wk.
Conclusion: We have shown for the first time in a direct comparison study that high-intensity PRT, but not cycling or sham exercise, can improve muscle strength, peak power, and muscle endurance in both affected and unaffected lower limbs after chronic stroke by a significant and clinically meaningful amount. Although strength gains plateaued earlier than anticipated, adherence to the intended continuous high-intensity progressive overload protocol was largely achieved (average load of 84% +/- 4% of one repetition maximum).