This is the second morning this week where I've felt dizzy/lightheaded on the subway in the morning. (For NYers, I'm only going Grand Central to Fulton St too.) I've been able to get a seat en route and clearly need to make it more of a priority now. I just wish I knew what was causing it and how to try and prevent it. I haven't paid attention as to whether it happens on other times commuting (mid-day or afternoon) but have definitely noticed in the morning. The first time I ate an English muffin with peanut butter and greek yogurt not too long before. I had a cup of coffee but no water. So I figured I was getting dehydrated. This morning I had cottage cheese (was waiting to eat my bagel at my destination), coffee and some water. So now I don't now if it's dehydration? Anyone experience this? Any suggestions on how to prevent/avoid it?