Getting a Pump Fasted?

Today I worked out legs while fasting for 14 hours (at the time) and after my leg workouts, i started to do arms. I noticed my arms had an unreal pump, like one of the best I have ever had. Can anyone explain this/ give their feedback? Because I was so confused why I was vascular without any nutrients in me. (My last meal was at 7:30pm and my workout started at 11:30am the next day).

you had full glycogen stores from your previous day of eating