The aim of this study was to evaluate the effect of a continuous locomotor training on leg muscle EMG exhaustion during assisted stepping movements in a patient with motor complete spinal cord injury (SCI). EMG exhaustion and loss of potentials starts to develop in non-trained patients usually around six months after injury. In the trained patient examined in this study exhaustion was also observed but occurred with a delay of several months. In contrast to a non-trained patient no more EMG exhaustion was observed in a very chronic stage. At this time (12 years after injury) a basic locomotor pattern of leg muscle activity of reduced amplitude could still be elicited but it was resistant to exhaustion and unchanged in amplitude after 12 minutes of assisted stepping. It is suggested that fatigue-resistant motor units prevail at this stage and can still be activated during stepping due to the training.