This is going to be a little bit of a stretch for imagination, but imagination yourself as a Roman general, and let's figure out what you're going to do.
The emails and tasks will begin to pile up, and the more you stretchyourself thin, the lower the quality of your work will become, and the less you will produce.
Tell yourself you'll do 20 push-ups in the next five minutes (a specific stretch goal) vs. five push-ups (non-stretch) or the vague idea that you'll do as many as you can.