This study determined the metabolic and hemodynamic responses in eight spinal cord injured (SCI) quadriplegics (C5-C8/T1) performing subpeak arm crank exercise (ACE) alone, subpeak functional electrical stimulation leg cycle exercise (FES-LCE) alone, and subpeak FES-LCE concurrent with subpeak ACE (hybrid exercise). Subjects completed 10 minutes of each exercise mode during which steady-state oxygen uptake (V̇O2), pulmonary ventilation (V̇(E)), heart rate (HR), cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), arteriovenous oxygen difference (a-v̄ O2 diff), and total peripheral resistance (TPR) were determined. Although mean V̇O2 for both ACE alone and FES-LCE alone was matched at 0.66 l/min, individualized power outputs ranged from 0-30 W (x̄ = 19.4 ± 1.3) and 0- 12.2 W (x̄ = 2.3 ± 0.6), respectively. Hybrid exercise elicited significantly higher V̇O2 (by 54 percent), V̇(E) (by 39-53 percent), HR (by 19-33 percent), and CO (by 33-47 percent), and significantly lower TPR (by 21-34 percent) than ACE or FES-LCE performed alone (P ≤ 0.05). Stroke volume was similar between hybrid exercise and FES-LCE alone, and these two exercise modes evoked a significantly higher SV (by 41-56 percent) than during ACE alone. These data clearly demonstrate that hybrid exercise creates a higher aerobic metabolic demand and cardiac-volume load in SCI quadriplegics than either subpeak levels of ACE or FES-LCE performed separately. Therefore, hybrid exercise may provide more advantageous central cardiovascular training effects in quadriplegics than either ACE or FES-LCE alone.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Rehabilitation Research and Development|
|State||Published - Dec 1 1992|
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