Working while fatigued may up heart risk

BIRMINGHAM , Ala., June 27 (UPI) -- There's a saying that hard work won't kill you but U.S. researchers suggest that working while fatigued may result in hypertension and heart disease.

Psychologists at the University of Alabama at Birmingham said their findings support a theory that exhausted individuals' cardiovascular systems are forced to work harder when they attempt to complete tasks, such as those encountered on the job or at school.

Study leader Rex Wright said that when people perceive a task as achievable they increase their effort to make up for their diminished capability due to fatigue. As a result, blood pressure tends to rise and remain elevated until the task is completed or individuals stop trying.

"Individuals who experience chronically exaggerated cardiovascular responses are believed to be at greater health risk than individuals who do not. Thus, the implication is that chronic fatigue may pose a health risk under some performance conditions."

Eighty subjects were offered to earn a modest prize by memorizing, in 2 minutes, two or six meaningless, three-letter sequences, while their heart rate and blood pressure were monitored.

The study, published in July issue of the International Journal of Psychophysiology, found subjects with moderate fatigue had stronger blood pressure increases than subjects who reported low fatigue.