Muscle fatigability

Muscle fatigability is a symptom in which muscles become weaker after repetitive use and recover with rest without actual loss of strength. It is a common symptom of myaglic encephalomyelitis and multiple sclerosis.

Possible causes of muscle fatigability in ME/CFS
Muscle biopsies have shown evidence of mitochondrial degeneration, deletions of mitochondrial DNA , and the reduction of mitochondrial activity.

In addition, evidence of oxidative damage to muscles has been found in CFS. Reduced levels of serum carnitine which return to normal after recovery and correlate with symptom severity.