Experiment with your pre running food to see what works for u- Everybody is different.    Oats, fruit, & yoghurt work best for me before I run but I do like the sound of the Beetroot juice so I will be experimenting with that.        The evening before a long run or a race I find pasta or a curry ( as long as it is a small potion & not too fiery) work for me.        Post race go with Protein & good carbs (veggies).