listen to your body!
to answer your question, take a break today! Have the day off exercise and let your body rest up.
I have asked the same question here on the forum and with my New Zealand neuro and also of Dr Parry (a CIDP/GBS foundation prof who works at U of M.) The responses have been the same, and that is exercise within reason. Take into consideration your usual activity levels, and assess daily how you feel. I was stubbornly determined to get ontop of this CIDP and wanted to relearn to walk and almost run before i could walk again! In general they said if the form of exercise ever reaches a hurting point definately stop it. But basically it is finding what you can tolerate without becoming fatigued. If you are fatigue your body cant repair as efficiently. If your body is repairing you need to allow for this and factor that into your schedule etc while stretching, and / or doing light cardio. Make sure you rest afterwards and sleep is the best form of rest, but putting your feet up for half an hour or so is also advisable. I understand the ‘use it or lose concept’ so it is also very important to try and incorporate some form of exercise into a DAILY routine but i am sure you are already very focused on this and no doubt if youve had the discipline and motivation to train for marathons etc it will be harder for you NOT to exercise than to exercise.
hope this helps.