I would like to train for a pull up contest with my friend. I can do ten now, and want to get to twenty or so.
The problem I'm having is that when I do a session of pull ups, later that day or the next day, the muscles in the top and back of my neck (trapezius, I think) get tight and strained, so that it's uncomfortable even to twist my neck enough to look over my shoulder.
If I rest a day, I get better, but the problem recurs when I do another session of pull ups.
What steps should I take to avoid these strains while doing pull ups?