What might be the reason for lightheadedness during a workout?

Hello everyone!

I’m a regular evening runner and usually get about 4 miles in a day. I’ve been trying to run early in the morning so I don’t have to worry about running later, but running in the morning has been pure torture for me.

Usually when I run in the evening, I can get my 4 miles in easy and have energy afterwards. But since I’ve switched over to morning runs, I can only get about 3 miles in, and the whole run consists of a pounding headache, trouble swallowing, and then afterwards lightheadedness and fatigue.

Before my morning runs, I usually drink 2 cups of water, and 8 oz Gatorade, and a bagel with cream cheese. Today I added an 8 oz protein shake along with those and still felt miserable the whole time.

I feel like it’s hypoglycemia, but all over the internet it seems as if people eat next to nothing before their runs and they are fine!

Any possible reasons for these crappy runs? What should I do about it?