Quote:
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Originally Posted by Taosman
This is a little silly.
As was pointed out.
Not busting ya!  |
Actually, not so silly as you may think. Although the effects of heat and dehydration are usually discussed for their effects on stamina and muscle movement, even for kickers, extreme heat affects concentration and cognitive skills. The mechanism by which this effect works has been traced to core body temperature and to dehydration.
A typical study, this from the
Journal of Athletic Training, a scholarly, peer-review journal in the field...
Zuri, RE; Cleary, MA; Lopez, RM; Jones, LC (Florida International University, Miami, FL).
Abstract
Limited research suggests that cognition may be impaired by active dehydration induced by exercise in a hot, humid environment. We used the latest technological advances in computerized neuropsychological testing to identify the effects of acute active dehydration on cognitive response times. The research design consisted of a test-retest design with one experimental group. Ten healthy male participants (25.6 ±1.6 years, 80.3 ±4.3 kg) were assessed in euhydrated and dehydrated conditions using the Headminder<SUP>™</SUP> Cognitive Stability Index® test. Participants were actively dehydrated by 3.27 ±.08% body mass loss via heat stress trial of treadmill exercise in a hot, humid environment (33.1 ±3.1°C, 55.1 ±8.9% relative humidity) followed by rest in a thermoneutral environment until core (rectal) body temperatures returned to baseline (50.2 ±17.05 min, range = 28 – 80 min). Prior to both cognitive performance tests, participants rated motivation (on a 13 cm visual analog scale) and fatigue severity (on a 9-point Likert scale). Dependent t-tests were used to identify differences between the euhydrated and dehydrated conditions on all measures. Motivation ratings were not significantly different (t<SUB>9</SUB> = 2.181,
P = .057) between conditions; however, ratings did reveal a 17.86% decrease from the euhydrated (8.4 ±1.8 cm) to the dehydrated (6.9 ±2.9 cm) condition. Fatigue severity ratings were significantly (t<SUB>8</SUB> = −5.774,
P = .001) increased 62.48% from the euhydrated (2.00±1.41) to the dehydrated (5.33 ±1.73) condition. Cognitive testing revealed that the composite processing speed factor raw scores were significantly (t<SUB>9</SUB> = −3.329,
P = .009) decreased 8.33% in the dehydrated (2.78 ±.43) compared to the euhydrated (3.03 ±.32) condition. No other composite scores were significantly different. Of the subtests, the symbol scanning response time was significantly (t<SUB>9</SUB> = 6.692,
P ≤ .001) decreased 16.16% in the dehydrated (3.16 ±.57 ms) compared to the euhydrated (3.76 ±.17 ms) condition. The response direction 1 response time was significantly (t<SUB>9</SUB> = 6.692,
P ≤ .001) increased 4.59% in the dehydrated (.54 ±.01 ms) compared to the euhydrated (.51 ±.01 ms) condition. Although not significant (t<SUB>9</SUB> = 2.257,
P = .051), the response direction 2 response time was decreased 5.05% in the dehydrated (.63 ±.08 ms) compared to the euhydrated (.66 ±.10 ms) condition. Other non-significant findings revealed that response speed of several subtests increased in the dehydrated condition. Our preliminary findings indicated that response speeds may be impaired when dehydrated thus potentially increasing susceptibility to injury or reducing athletic performance.