1. Measurements of peak oxygen uptake (VO2peak) during passive leg cycling (PLC) combined with arm crank ergometry (ACE), leg vascular occlusion (100mmHg above systolic BP) combined with ACE, and FES isometric contractions combined with ACE in spinal cord injured (SCI). All the above mentioned parameters will be compared to Functional Electrical Stimulated (FES) lower extremity cycling combined with ACE (FEShybrid). The hypothesis is that VO2peak is significantly higher during FES hybrid cycling when compared to peak and submaximal PLC, leg vascular occlusion and ACE. But the values for VO2peak during FES isometric contractions combined with ACE is not significantly different from FES hybrid cycling.