chronic fatigue syndrome

Chronic fatigue syndrome leaves many people completely drained of energy and struggling to think clearly, and their symptoms often worsen after mental or physical exertion -- a reaction known as post-exertional malaise.

The study included 57 people diagnosed with chronic fatigue syndrome and 25 healthy individuals of similar age and activity level.

Results showed that people with chronic fatigue syndrome took in roughly the same amount of oxygen as the control group -- their peak VO2 max was similar.

"It is well known that chronic fatigue syndrome patients often have dysautonomia in the form of orthostatic intolerance, which means you feel worse when upright and not moving. This raises the heart rate and leads to hyperventilation."

Katie Livings has chronic fatigue syndrome which causes exhaustion, headaches and sensitivity to light.