Massive headaches?

[POKEROMGLOL]

Near the end of my workouts I have been getting these killer headaches that feel exactly like migraines. Despite my muscles still having a little bit left, I can't really continue.

I have no problem pushing myself to the max doing HIIT or on fast 3 mile runs.

Anyone else have this problem or know how you can get around it. I have done a bit of reading on it, but haven't gotten any specific answers.