Catecholamine response to exercise and training in individuals with spinal cord injury

It is unknown whether the catecholamine (CAT) response to acute exercise and prolonged training in humans with spinal cord injury (SCI) is similar to that of neurologically intact man. Plasma samples were collected from seven subjects with chronic SCI (level of injury C5-T7) at rest and during voluntary arm-crank ergometry (ACE) before and after 6 months of training with functional electrical stimulation cycle ergometry (FES-CE). Similar plasma collections were made during one FES-CE exercise training session after 6 months of training. Norepinephrine (NE) and epinephrine (EPI) were measured by HPLC. After FES-CE training, resting NE decreased 37% (950 +/- 150 vs 1510 +/- 350 pmol.l-1 pretraining); resting EPI decreased 80% (54 +/- 10 vs 163 +/- 32 pmol.l-1 pretraining) (P < 0.05 by paired t-tests). No significant changes were observed in group means after training for the CAT response to submaximal ACE; however, five of seven subjects exhibited greater increments in plasma NE with ACE after FES-CE training. Acute FES-CE exercise elicited a 55-844% increase in NE, and a 35-350% increase in EPI above resting values with power outputs eliciting heart rates of 90-146 bpm. These data provide evidence for a systemic CAT response in subjects with SCI during acute FES-CE and reduced resting CAT following 6 months of training with FES-CE.