Frederick M. Ivey

BACKGROUND AND PURPOSE: Physical inactivity propagates disability after stroke through physical deconditioning and learned nonuse. We investigated whether treadmill aerobic training (T-AEX) is more effective than conventional rehabilitation to improve ambulatory function and cardiovascular fitness in patients with chronic stroke. METHODS: Sixty-one adults with chronic hemiparetic gait after ischemic stroke (>6 months) were randomized to 6 months (3x/week) progressive T-AEX or a reference rehabilitation program of stretching plus low-intensity walking (R-CONTROL). Peak exercise capacity (Vo2 peak), o2 consumption during submaximal effort walking (economy of gait), timed walks, Walking Impairment Questionnaire (WIQ), and Rivermead Mobility Index (RMI) were measured before and after 3 and 6 months of training. RESULTS: Twenty-five patients completed T-AEX and 20 completed R-CONTROL. Only T-AEX increased cardiovascular fitness (17% versus 3%, delta% T-AEX versus R-CONTROL, P<0.005). Group-by-time analyses revealed T-AEX improved ambulatory performance on 6-minute walks (30% versus 11%, P<0.02) and mobility function indexed by WIQ distance scores (56% versus 12%, P<0.05). In the T-AEX group, increasing training velocity predicted improved Vo2 peak (r=0.43, P<0.05), but not walking function. In contrast, increasing training session duration predicted improved 6-minute walk (r=0.41, P<0.05), but not fitness gains. CONCLUSIONS: T-AEX improves both functional mobility and cardiovascular fitness in patients with chronic stroke and is more effective than reference rehabilitation common to conventional care. Specific characteristics of training may determine the nature of exercise-mediated adaptations.

OBJECTIVE: To compare the efficacy of treadmill exercises and stretching and resistance exercises in improving gait speed, strength, and fitness for patients with Parkinson disease. DESIGN: A comparative, prospective, randomized, single-blinded clinical trial of 3 types of physical exercise. SETTING: The Parkinson's Disease and Movement Disorders Center at the University of Maryland and the Baltimore Veterans Affairs Medical Center, Geriatric Research Education and Clinical Center. PATIENTS: A total of 67 patients with Parkinson disease who had gait impairment were randomly assigned to 1 of 3 arms of the trial. INTERVENTIONS; (1) A higher-intensity treadmill exercise (30 minutes at 70%-80% of heart rate reserve), (2) a lower-intensity treadmill exercise (50 minutes at 40%-50% of heart rate reserve), and (3) stretching and resistance exercises (2 sets of 10 repetitions on each leg on 3 resistance machines [leg press, leg extension, and curl]). These exercises were performed 3 times a week for 3 months. MAIN OUTCOME MEASURES: The primary outcome measures were gait speed (6-minute walk), cardiovascular fitness (peak oxygen consumption per unit time [$$ VO2], and muscle strength (1-repetition maximum strength). RESULTS: All 3 types of physical exercise improved distance on the 6-minute walk: lower-intensity treadmill exercise (12% increase; P=.001), stretching and resistance exercises (9% increase; P<.02), and higher-intensity treadmill exercise (6% increase; P=.07), with no between-group differences. Both treadmill exercises improved peak $$ VO2 (7%-8% increase; P<.05) more than did the stretching and resistance exercises. Only stretching and resistance improved muscle strength (16% increase; P<.001). CONCLUSIONS: The effects of exercise were seen across all 3 exercise groups. The lower-intensity treadmill exercise resulted in the greatest improvement in gait speed. Both the higher- and lower-intensity treadmill exercises improved cardiovascular fitness. Only the stretching and resistance exercises improved muscle strength. Therefore, exercise can improve gait speed, muscle strength, and fitness for patients with Parkinson disease. The combination of treadmill and resistance exercises may result in greater benefit and requires further investigation.

PURPOSE: The purpose of this study was to compare age and gender effects of strength training (ST) on resting metabolic rate (RMR), energy expenditure of physical activity (EEPA), and body composition. METHODS: RMR and EEPA were measured before and after 24 wk of ST in 10 young men (20-30 yr), 9 young women (20-30 yr), 11 older men (65-75 yr), and 10 older women (65-75 yr). RESULTS: When all subjects were pooled together, absolute RMR significantly increased by 7% (5928 +/- 1225 vs 6328 +/- 1336 kJ.d-1, P < 0.001). Furthermore, ST increased absolute RMR by 7% in both young (6302 +/- 1458 vs 6719 +/- 1617 kJ x d(-1), P < 0.01) and older (5614 +/- 916 vs 5999 +/- 973 kJ x d(-1), P < 0.05) subjects, with no significant interaction between the two age groups. In contrast, there was a significant gender x time interaction (P < 0.05) for absolute RMR with men increasing RMR by 9% (6645 +/- 1073 vs 7237 +/- 1150 kJ x d(-1), P < 0.001), whereas women showed no significant increase (5170 +/- 884 vs 5366 +/- 692 kJ x d(-1), P = 0.108). When RMR was adjusted for fat-free mass (FFM) using ANCOVA, with all subjects pooled together, there was still a significant increase in RMR with ST. Additionally, there was still a gender effect (P < 0.05) and no significant age effect (P = NS), with only the men still showing a significant elevation in RMR. Moreover, EEPA and TEE estimated with a Tritrac accelerometer and TEE estimated by the Stanford Seven-Day Physical Activity Recall Questionnaire did not change in response to ST for any group. CONCLUSIONS: In conclusion, changes in absolute and relative RMR in response to ST are influenced by gender but not age. In contrast to what has been suggested previously, changes in body composition in response to ST are not due to changes in physical activity outside of training.

Evidence from several studies consistently shows decline in cardiorespiratory (CR) fitness and physical function after disabling stroke. The broader implications of such a decline to general health may be partially understood through negative poststroke physiologic adaptations such as unilateral muscle fiber type shifts, impaired hemodynamic function, and decrements in systemic metabolic status. These physiologic changes also interrelate with reductions in activities of daily living (ADLs), community ambulation, and exercise tolerance, causing a perpetual cycle of worsening disability and deteriorating health. Fortunately, initial evidence suggests that stroke participants retain the capacity to adapt physiologically to an exercise training stimulus. However, despite this evidence, exercise as a therapeutic intervention continues to be clinically underutilized in the general stroke population. Far more research is needed to fully comprehend the consequences of and remedies for CR fitness impairments after stroke. The purpose of this brief review is to describe some of what is currently known about the physiological consequences of CR fitness decline after stroke. Additionally, there is an overview of the evidence supporting exercise interventions for improving CR fitness, and associated aspects of general health in this population.