1. To perform a controlled, randomized, double-blind clinical trial to test the effects of high-intensity resistance exercise at the shoulder and elbow. Two interventions will be compared: standard functional rehabilitation (SFR), and standard functional rehabilitation combined with high-intensity resistance exercise (strength training) (SFR+STR). We will study persons with post-stroke hemiparesis in the subacute phase of recovery, i.e. having completed all outpatient therapy programs, but still less than 6 months post-CVA. Outcome measures will include strength (maximal voluntary isovelocity joint torque), hypertonia (onset threshold of the stretch reflex, Modified Ashworth Scale), standard clinical assessment of activities of daily living (Barthel Index, Functional Independence Measure), and upper extremity motor function (Fugl-Meyer exam, Functional Test of the Hemiparetic Upper Extremity).