In the "Professor Kenny De Meirleir on Chronic Fatigue" video, he states that the non-CFS twins have aerobic capacity well below the general population. Is that this 2001 study? "Cognitive compromise following exercise in monozygotic twins discordant for chronic fatigue syndrome: fact or artifact?" http://www.ncbi.nlm.nih.gov/pubmed/11388121 What else is there on that same topic? I'm finding twins studies but not on exercise. Thanks.