Energetic and cardiovascular responses to treadmill walking and stationary cycling in subjects with incomplete spinal cord injury.

Abstract

Randomized controlled trail. To investigate if people with incomplete spinal cord injury (SCI) can perform high-intensity weight-bearing exercise by comparing cardiovascular responses at maximal workloads during stationary cycling and treadmill walking, and to explore mechanical efficiencies at sub-maximal workloads. Sunnaas Rehabilitation Hospital, Nesoddtangen, Norway. Fifteen people with incomplete SCI and 15 healthy control subjects performed sub-maximal and maximal exercise tests of both stationary cycling and uphill treadmill walking on separate days. Oxygen uptake (VO(2); l min(-1) and ml kg(-1) min(-1)), carbon dioxide production (VCO(2); l min(-1)), respiratory exchange ratio (RER) and heart rate (HR) were continuously measured throughout the tests. The SCI group showed no significant differences in peak VO(2) (2.42±0.68 l min(-1) versus 2.58±0.76 l min(-1), P=0.19) or other cardiovascular responses at maximal workloads for stationary cycling as compared with uphill treadmill walking, except for higher RER during the cycle test. The control subjects exhibited a significantly higher peak VO(2) during the treadmill test as compared with the cycle test (P=0.007). Both groups had lower mechanical efficiency when walking as compared with cycling, but the mean difference between cycling and walking was not significantly different between the groups during sub-maximal workloads (P >0.24). Subjects with incomplete SCI were able to perform high-intensity weight-bearing exercise and exhibited similar mechanical efficiencies at sub-maximal workloads as healthy controls. Uphill walking might be a good alternative to weight-bearing exercise for increasing the physical capacity of people with incomplete SCI.