Hello,
Everytime I go for a LSR, I end up with a killer headache! 
I take on plenty of fluid before, drink Lucozade body fuel throughout and Lucozade recovery after. I also try and eat well and stay hydrated after.
However, no matter what I do, I get a headache about 3-4hrs after my run! 
I have tried eating more, eating less, drinking more, drinking less, sweet tea, chocolate...but always end up having to resort to painkillers to get rid.
Any advice would be greatly recieved, either on prevention or cure!