THURSDAY, July 3 (HealthDay News) -- Doing mental or physical
work while exhausted may harm your health, a new study shows.
Researchers at the University of Alabama at Birmingham found
that fatigued people had bigger spikes in blood pressure than
well-rested people while doing a memorization test.
When fatigued people regard a task as worthwhile and achievable,
they increase their effort to compensate for their diminished
capability, explained study author and psychologist Rex Wright. As
a result, a tired person's blood pressure increases and remains
elevated until the task is completed or the person gives up.
"Our findings are relevant to health because of links that have
been established between cardiovascular responsiveness and negative
health outcomes, including hypertension and heart disease," Wright
said in a prepared statement.
"Individuals who experience chronically exaggerated
cardiovascular responses are believed to be at greater risk than
individuals who do not. Thus, the implication is that chronic
fatigue may pose a health risk under some performance conditions,"
he explained.
In this study, Wright and colleagues told 80 volunteers they
could win a modest prize by memorizing two or six nonsense trigrams
(meaningless, three-letter sequences) within two minutes. Compared
to volunteers with low levels of fatigue, those with moderate
fatigue had stronger blood pressure while doing the two-trigram
memorization task.
"Presumably this was because the moderately fatigued subjects
viewed success as relatively hard, but still possible and
worthwhile. Subjects who reported moderate fatigue had relatively
reduced blood pressure increases in the six-trigram condition,
presumably because they view success there as impossible or too
difficult to be worth the effort," Wright said.
Volunteers with high levels of fatigue had low blood pressure
increases in both the two- and six-trigram tasks. This likely means
they viewed both tasks as too difficult to attempt, the researchers
said.
The study was published in the July issue of the
International Journal of Psychophysiology.
More information
The MedlinePlus Medical Encyclopedia has more about
fatigue.
