Good point. Actually, my buddy recommended NO2 for it's "pump" action, meaning you can feel the added energy boost as you workout.
One other form of muscle relieve I found came from fluoxetine, after my family doctor prescribed it for anxiety after I lost job and out of work for several months. My discovery revealed how fluoxetine has been tested to improve MDA symptoms...interesting!
I take L-Citrulline which has a very similar effect on Nitric Oxide production, but I can only take about 1/2 capsule a day because it is such a potent vasodilator that it lowers my blood pressure too much.
I can't say that I notice a lot of difference in the myotonia, but it does seem to help with overall exercise tolerance. The problem with taking arginine is it seems to encourage proliferation of viruses in the herpes family. This can include cold sores, HPV and even shingles.
I have seen very good results taking Acetyl-L-Carnitine (ALCAR). It seems to have a phosphorus-sparing effect and since we have a very high requirement for ATP it can also improve exercise tolerance. ALCAR can increase serotonin levels and have a similar effect to some SSRIs.