A long time ago there was mention of a speed-building practice in a thread on the blog:
http://gregg-shorthand.com/2008/12/19/methods-of-attacking-shorthand-speed/
(Note: Link to the _Factors of Shorthand Speed_ document now kaputt!)
The idea was practicing for a long time without breaks to force the fatiguing muscles to learn how do the work with minimal effort.
I am wondering if it would be possible to do something similar, but in a shorter time — what would happen if a person were to practice with a weighted pen? Something wrapped around the barrel, or attached to the top, perhaps. Has anyone ever heard of such an experiment? What would happen?