Well I usually run on empty, but last night I went out with some other mums, had two large glasses of wine, ate chips and calamari, woke up with a mini hangover and so far have eaten banana, porridge and a bagel with nut butter. And I am planning on a run at midday. I'll let you know how that goes...!
I generally feel lighter and more efficient without food. Last week I did 10 miles empty and felt great, though I did nothing but eat for he rest of the day!
One thing I have noticed since I ramped up the exercise ( a week is pilates, gym, intervals, short run, long run) is that I cannot do it low carb. My body just can't cope with the demands and I started to need carbs. I do try to keep the wheat to a minimum as it makes me hungrier than when I started, but I have started to eat a lot more in general. I think the weights make a big difference.
standing there is nothing better than a hamstring stretch from my PT 
. Mine is also my pilates teacher and I always secretly hope it will be a small class one week and he will stretch us all a bit!