Hi Lucy: I passed on your question to Suzie Mudge who is a physio and a member of the Medical Advisory Board who is an expert on rehabilitation and muscle fatigue. Here is her answer.

Our muscles are made up of thousands of motor units (motor unit = motor nerve and muscle fibres that it supplies). Following GBS, you might recruit fewer motor units (depending on the amount of recovery you’ve had). You can often compensate by increasing the size and efficiency of the motor units that are working. But this leads them to be more at risk of overworking, which can lead to muscle &/or central fatigue. So sorry for being so technical but the short answer is that even though you make a good motor recovery, you are likely to experience more fatigue than previously.