My partner, who has congestive heart failure, has had great success with carnitine. Muscle weakness due to cachexia is very common in CHF. I had found research that indicated carnitine improved exercise tolerance for CHF, so he started taking 2x500mg/day.
At the time of diagnosis he lost about 15 pounds of muscle mass during a week long stay in hospital, so it was hard at first to tell what effect was the carnitine and how much was just recovery. However, he did recover his execise capacity very quickly, much to the surprise of his cardiologist. And a few months later, when he returned to his physically demanding job, he built up muscle very quickly. He continues to take it, along with 2×1g of taurine each day (and a bunch of other supplements), and finds he bulks up much faster than he used to.
Suspected SpA. HLA B27, xray, u/sound, blood tests all -ve. Ancient history of plantar fasciitis, SI joint pain, knee arthritis. Recent history of tendinitis, neck pain, debilitating finger pain and stiffness (especially mornings). No diagnosis, no meds.
2010 - stopped eating dairy
2012 - stopped eating wheat
2014 - stopped eating all grains
Jan 2017 - discovered NSD - 98% improvement in symptoms, continually amazed by my results, wish I'd found kickAS sooner