How do you deal with the after lunchtime sleepiness at work?

That's a good one to hang up in my office.

I tend to pace when my brain is working on a problem. When I do some heavy analysis, I often look at data for 20-30 minutes and then pace for 15-20 minutes as I process.

Good thing my office is empty most of the time, so I don't bother others.

Of course after 4-5 hours my brain is done so I often find and excuse to leave the office after lunch. Gotta go walk a field/visit a customer etc...