Brainstorming

Bat a balloon to brainstorm. You trade some brain power for the balloon, but in return your thoughts are clearer. 

The point of brainstorming isn't to generate quality thoughts, anyway. The game is quantity. It's about coming up with as many ideas as possible during this 1 hour meeting. So, simple, repetitive activity helps to:

Increase cerebral blood flow

Decrease Cortisol levels

Release Endorphins

Improve mood

Break a rut

If gamification isn't your thing, don't bat a balloon. But it's a good idea to take your mind for a walk before a session.