Excess post-exercise oxygen consumption in spinal cord-injured men

Abstract

This study examined excess post-exercise oxygen consumption (EPOC) following arm cranking in men who had a traumatic spinal cord injury (SCI). Six physically active SCI men with a lesion level between T10 and T12 and six able-bodied (AB) men who were matched according to upper body peak VO₂ performed 30 min of arm-cranking at 65–70% peak VO₂. Baseline measurements were recorded during the last 10 min of a 40-min seated rest. Subjects remained seated during recovery for 40 min or until VO₂ returned to baseline, whichever was longer. Plasma lactate concentration was measured at rest, at the end of exercise, and at 10, 20 and 40 min of recovery. EPOC duration was not significantly different (P>0.05) between SCI [23.2 (7.9) min; mean (SE)] and AB [35.0 (15.4) min] men, nor was there a significant group difference in EPOC magnitude [36.8 (7.8) kJ for SCI and 53.0 (22.8) kJ for AB]. There was no significant difference in recovery heart rate (HR) or respiratory exchange ratio (RER) between SCI and AB. However, HR measured at the end of the EPOC period was significantly elevated (P<0.001) and RER significantly lower (P<0.03) for both groups when compared to baseline. Lactate concentration was not significantly different between the groups at any sampling period. The findings suggest that physically active SCI men have a similar energy expenditure and time frame for recovery from arm crank exercise as their AB counterparts. Similar to what has been reported following lower body exercise, arm crank exercise elicits a higher HR and lower RER at end-EPOC when compared to pre-exercise values.