After a traumatic brain injury, many people experience chronic fatigue. Past studies have suggested that chronic fatigue may be the result of an increased demand on cognitive processes after the injury. However, a recent study suggests that decreased cardiorespiratory fitness may also contribute to fatigue.
By measuring oxygen consumption during a treadmill test of people who have had a traumatic brain injury, researchers found that they show a ventilation capacity below that of the healthy controls. A low ventilation capacity suggests that there may be difficulty in meeting metabolic demands during daily activities, which can contribute to the sense of fatigue.
A prescribed regimen of exercise may help people with traumatic brain injury increase their cardiorespiratory fitness, which will increase ventilation capacity over time. Although an exercise routine may be difficult to start and adhere to when feeling profoundly fatigued, a slow progression towards greater activity may ultimately reduce their chronic fatigue.
Amonette WE & Mossberg KA. Ventilator anaerobic thresholds of individuals recovering from traumatic brain injury compared with non-injured controls. Journal of Head Trauma Rehabilitation. (October 2013).