Determination and possible application of the aerobic gas exchange threshold in aerobically untrained paraplegic subjects based on stimulated cycle ergometry

PURPOSE: To accurately characterise cardiopulmonary baseline performance in aerobically untrained paraplegic subjects by means of an incremental exercise test (IET) and to derive possible training recommendations based on these measurements. METHODS: Twelve motor complete paraplegic subjects with no previous experience in stimulated leg-cycling participated in the study. Exercise testing was performed on a recumbent FES-tricycle by means of a work rate and cadence controlled IET until maximal work rate was reached. Heart rate (HR) and respiratory parameters were recorded continuously. RESULTS: Peak oxygen uptake was 671 +/- 192 mL min(-1) (mean + standard deviation), peak HR 90 +/- 12 beats min(-1), net peak power 8.4 +/- 3.3 W and peak minute ventilation 23.6 +/- 7.5 L min(-1). Aerobic gas exchange threshold (GET) was found to be 51% +/- 10% of peak oxygen uptake and corresponded to 41% +/- 13% of peak power. CONCLUSIONS: A cadence and work rate controlled exercise test allows the determination of cardiopulmonary parameters during stimulated cycle ergometry even in aerobically untrained paraplegic subjects. The precise determination of GET allows an appropriate exercise intensity to be prescribed and thus provides a suitable method for exercise intensity calculation in the spinal cord injured population in the future.