headaches during workout

So the past few times I have worked out (cardio) I have been getting really bad headaches and dizziness, have any of you felt this way, do you know what it may be or how i can stop it??? thanks
Kristin

Are you taking any supplements?  Some are too strong for our systems and do cause headaches.

How strenuous is your cardio? Can you still talk while doing it or are you short of breath? This can also induce a headache.

Are you properly hydrated?   Many factors to consider, so pay attention to your body, and be safe.

No I'm not taking anything, and I can talk in short sentences I think and I drink a lot of water, hmmm idk...

I know you say you're drinking a lot of water, but what does that mean?  For instance, I can easily drink half a gallon before during and after my workout.  If you're doing heavy cardio and only taking in one bottle of water (16oz.), you might be dehydrated.  Also, are you drinking water all day long?  It's important to keep that hydration up all day, not just during your exercise.

Remember, it's dehydration that causes a hangover and we all know what that feels like!  If what you're feeling is similar, DRINK, DRINK, DRINK!!! (Water, not that other stuff!!!)

Yeah I would definitely say drink more water and drink it throughout the day. Ifyou swallow 16 ounces of water in a half hour and dont rink anymore the rest of the day you will still be dehydrated. It takes a moment for water to get ito your system.

You might be overdoing the cardio as well.

as a ps if anyone out there thinks they are drinking to much water (I have sen many of these topics) Yu arent and here is what can happen if you think you are

It's also possible that your blood sugar is crashing.

Are you eating enough?