Hybrid functional electrical stimulation exercise training alters the relationship between spinal cord injury level and aerobic capacity.

OBJECTIVE: To test the hypothesis that hybrid functional electrical stimulation (FES) row training would improve aerobic capacity but that it would remain strongly linked to level of spinal cord lesion because of limited maximal ventilation. DESIGN: Longitudinal before-after trial of 6 months of FES row training. SETTING: Exercise for persons with disabilities program in a hospitaL. PARTICIPANTS: Volunteers (N=14; age range, 21-63y) with complete spinal cord injury (SCI) (T3-11) who are >2 years postinjury. INTERVENTION: Six months of FES row training preceded by a variable period of FES strength training. MAIN OUTCOME MEASURES: Peak aerobic capacity and peak exercise ventilation before and after 6 months of FES row training. RESULTS: FES row training significantly increased peak aerobic capacity and peak minute ventilation (both P<.05). Prior to FES row training, there was a close relation between level of SCI and peak aerobic capacity (adjusted R(2)=.40, P=.009) that was markedly reduced after FES row training (adjusted R(2)=.15, P=.10). In contrast, the relation between level of injury and peak minute ventilation was comparable before and after FES row training (adjusted R(2)=.38 vs .32, both P<.05). CONCLUSIONS: The increased aerobic capacity reflects more than increased ventilation; FES row training effectively circumvents the effect of SCI on peak aerobic capacity by engaging more muscle mass for training, independent of the level of injury.