Khaberni - New research from the University of California suggests that "individuals who are physically fit may be better prepared to deal with the negative effects of dryness".
The most physically fit may be more capable of maintaining performance with mild dehydration
Theodore Garland, the research team supervisor said, "Physical fitness has many known benefits, but this research highlights a benefit that people may not have realized. Being in good physical shape may help the body and brain better adapt to the challenges of dryness".
In a study conducted on selectively bred "high-runner" mice, scientists found that the fitter animals increased their voluntary running activity when deprived of water, a discovery that might have implications for human performance and health under environmental stress.
Deprivation of water
According to "Medical Express", the researchers studied how water deprivation for 24 hours affected the voluntary running behavior on wheels and body mass in trial mice.
To increase the chance of observing effects, the study used mice from high-running strains, which run about three times more than control group mice.
The experiment
In the experiment, mice from both the high-running and light-running strains ran on wheels for six days. On the 7th day, the researchers deprived half of the mice of water for 24 hours. The other half were allowed free access to water.
Garland said, "What we found was surprising; high-runner mice ran longer distances and at a faster pace when they did not have access to water, and in some cases, for longer periods".
Despite losing body weight - a sign of dehydration - their activity levels increased.
Dehydration is typically associated with fatigue and reduced activity. Yet, it was remarkable to see these mice increase their running in that situation.
Explanation of the active response to dehydration
The team proposed a possible explanation: a behavioral phenomenon known as reward substitution.
In this theory, the mice replace the reward they typically get from drinking water (a basic biological drive) with the reward they get from running (which might also be a biological drive).
Running provides a reward
Garland said, "If an enjoyable activity, such as drinking water, is forfeited, the brain might compensate by augmenting another rewarding behavior, like running". And "the high-runner mice managed to do this thanks to their high physical fitness, compared to the regular mice".
Garland believes that these findings might have implications for humans, especially in a warmer world.
He said, "With global temperatures rising and water availability decreasing, dehydration is a more common challenge. Our data suggest that the more physically fit individuals may be more capable of maintaining performance, even with mild dehydration".
