I recently got sent this:
It gave me an appreciation of the amount of intricate detail that goes into keeping our bodies running and the many methods our bodies have of introducing fuel, with or without carbohydrates.
I would say, leave well enough alone. If you workout during a fast, keep fasting. Believe me you won't fall over from lack of glycogen. Unless of course you just ran an ultramarathon. Wait till your fast is done then eat. You'll replenish soon enough.