Do you think that's from the increase in circulation? Or do you think other factors contribute? If it's just from circulation, then exercise should be an acceptable substitute.

There have been recent studies that found mental performance went up immediately after brisk walking. Of course, I realize that's more work than drinking something, but it has extra benefits that make it worthwhile.

Or maybe tea is the right balance point for you. It has less caffeine than coffee for example.

At http://en.wikipedia.org/wiki/Postura...ardia_syndrome it says that caffeine helps some patients and worsens others.