New York, June 29: Working hard when fatigued might
please bosses, but the tendency could be harmful to the health
of an individual, researchers have found.
The theory that exhausted individuals' cardiovascular
systems are forced to work harder when they attempt to
complete tasks, has been supported by a research by
psychologists at University of Alabama at Birmingham (UAB).
The research, published in the July issue of the
'International Journal of Psychophysiology' found that
fatigued individuals had larger blood pressure increases than
rested ones, under conditions where they viewed success as
both possible and worthwhile.
The effects were determined by efforts on part of the
participants in the research, said psychologist Rex Wright who
led the study.
When fatigued individuals perceive a task as achievable
and worth doing, they increase their effort to make up for
their diminished capability due to fatigue, Wright said.
As a result, blood pressure tends to rise and remain
elevated until the task is completed or individuals stop
trying because they think success is impossible or too
difficult to be justified.
"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," the psychologist said.
"Individuals who experience chronically exaggerated
cardiovascular responses are believed to be at greater health
risk than those who do not. Thus, the implication is that
chronic fatigue may pose a health risk under some performance
conditions."
In the study, 80 subjects were provided the opportunity
to earn a small chance of winning a modest prize by
memorising, in two minutes, two or six nonsense trigrams.
Trigrams are meaningless, three-letter sequences, such as AED.
Before the memorisation period, the subjects completed a
survey that included questions about how fatigued they felt.
During the memorisation period, the investigators monitored
the subjects' heart rate and blood pressure responses.
The data indicated that subjects who reported moderate
fatigue had stronger blood pressure increases than subjects
who reported low fatigue in the two-trigram condition.
"Presumably this was because the moderately fatigued
subjects viewed success as relatively hard, but still possible
and worthwhile," Wright said.
"Subjects who reported moderate fatigue had relatively
reduced blood pressure increases in the six-trigram condition,
presumably because they viewed success there as impossible or
too difficult to be worth the effort."
Subjects who reported very high fatigue had low blood
pressure increases in both task conditions. This was
interpreted to suggest that even the easy task was too
difficult for them.
"It might be argued that fatigue is of little concern
from a health standpoint because people will tend to withdraw
effort once they become fatigued," Wright said. "The problem
with this view is that it fails to recognise that people do
not always have the luxury of withdrawing effort or perhaps
the wisdom to do so."
"To be sure, fatigue should sometimes be so compelling
that it demands effort withdrawal. However, in many instances
it will be below this threshold and merely amplify the effort
that people expend," he said.
Bureau Report