BETHESDA, Md. (AP) - Researchers hooked Zach Ault to medical monitors as he slowly climbed onto a gym bike. An invisible disease is sidelining this once avid athlete and he knew the simple exercise would wipe him out - but Ault was pedaling for science.
Chronic fatigue syndrome is one of medicine's most vexing mysteries. Now doctors at the National Institutes of Health are using volunteers like Ault for a unique study that pushes their limits in search of what's stealing all their energy.