Before I mentioned that the difficulty of reaching high levels of muscle tension, which could be equal to heavy weight loading, may limit the efficiency of our self-resistance training (SRT). The usage of short isometric tension before movements could help to overcome this problem. My experience also shows that we can reach higher efficiency of SRT if we correctly coordinate our breathing with muscle tension and movement in reps. The figure below explains how we can do it. I use this method for both co-contraction exercises and exercises with a stick.
Notes: 1. Time intervals were denoted approximately for long ROM SR exercises. You can
use shorter intervals.
2. When you begin training, using this method, use shorter time under tension.
3. Muscle tension should be > 50% of max; however, increase tension
gradually in accordance with your capabilities.
Michael,
This graph was not taken from the article. It is my explanation what I do to get max muscle tension during stick exercises or co-contraction.