Horrible headaches during workouts

Recently, I have changed my diet somewhat drastically and I have an inkling that this might be the cause of my headaches. I rarely get headaches, and almost never get them while I am working out. But the past few times that I have been to the gym, I have gotten splitting headaches. It has been almost 2 hours since I have been home from the gym and it is almost gone.

The big change that I made to my diet is that I cut out ALL sugars including all fruits (except for the naturally occurring ones in vegetables, milk, and the like). I upped my protein intake a lot. I am thinking that the lack of sugar could be a cause of my headaches...any insight would be appreciated!

Maybe low blood sugar or irregular glucose levels? Why have you cut out fruit? It doesn't alter your glycemic levels when eaten with a normal meal.

I was following the principles of the South Beach Diet which tells you to cut out all sugars (including fruit) for the first 2 weeks, but other than that I have been making sure to keep my calories high enough. So...I'm not sure if that would have had an effect.

Getting enough water?  Low hydration can cause headache's too.

ok so this is the third time in a row that I've gotten a HORRIBLE headache. I was definitely hydrated enough and I ate a fair amount throughout the day. One minute into my cardio workout my head just started pounding. I don't want to get too worried about it...but has anyone else ever experienced this?!

anyone? I don't want this to happen again tomorrow when I go to the gym :S

You might want to go in an visit the doctor and get checked out.

My first headaches were food based, needed more protein and carbs prior to workout. That worked on those. This month I got a splitting headache that started from the back of my neck to the top of my head. This turned out to be a pinched nerve in my back. Between my chiroprator and my massage therapist I have those headaches until control. I have learned to do traction every night. and this helps as well. Good Luck.

I sometimes get bad headaches from cardio too but dont know what they are from.  My blood pressure can run really low and when it workout sometimes it will spike and that is when I find I am working out too hard and I get the headaches.  I got myself a heartrate monitor and that seems to help to tell me when I am working out too hard.