Researchers document debilitating effect of exercise in CFS
After exercise at maximum exertion, CFS patients were slower on all measures of cognitive reaction time and scored lower on cardiopulmonary capacity measures than sedentary control subjects.
Research carried out to "compare the metabolic responses and neurocognitive consequences of a maximal exercise challenge between CFS and control subjects."
Concludes "These results indicate that exercise performance and neurocognitive abnormalities exist in CFS. The lack of any significant differences in lactate, glucose or nasal rhinometry precludes clear explanation for these differences."