Post-exertional malaise (PEM) is a worsening of many ME/CFS symptoms as a result of physical or mental exertion. Patients, ME/CFS organizatons, clinicians and researchers that work in the ME/CFS field often referred to it as "the marker," i.e., the main symptom that differentiates ME and CFS from other fatiguing illnesses. PEM can last for days to weeks after the exertion. (more...)
Dr J. Mark VanNess, PhD, is a member of the scientific advisory committee of the Workwell Foundation which specializes in two-day cardiopulmonary exercise testing (2-day CPET) for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia and other fatiguing conditions. He has been working on ME/CFS since 1999, and is particularly interested in issues of autonomic dysfunction and mechanisms that produce post-exertional malaise.
Dr VanNess serves as an Associate Professor of Health, Exercise & Sport Sciences, Department of Sport Sciences, and an Adjunct Instructor at the College of Engineering, both at the University of the Pacific, Stockton, California. (more...)