Physiological challenges in harsh environments: nutritional strategies for military and occupational operations

Show simple item record

dc.contributor Richardson, Mark T.
dc.contributor Curtner-Smith, Matthew
dc.contributor Schumacker, Randall E.
dc.contributor Neggers, Yasmin H.
dc.contributor Green, James M.
dc.contributor.advisor Bishop, Phillip A. Zhang, Yang 2017-03-01T14:40:28Z 2017-03-01T14:40:28Z 2011
dc.identifier.other u0015_0000001_0000585
dc.identifier.other Zhang_alatus_0004D_10638
dc.description Electronic Thesis or Dissertation
dc.description.abstract When humans are exposed to harsh environments, physical and mental performance is often substantially degraded. Few practical strategies are available to sustain performance under such conditions. The first of three studies evaluated the possible diuretic effect of caffeine following exercising in the heat. This is important for many U.S. military personnel who are engaged in combat situations in the Middle East, as dehydration may pose serious health issues. Eight participants completed four trials either with or without caffeine prior to the exercise and undertook a 3-h recovery period with or without fluid replenishment. Results revealed that ingestion of caffeine did not increase urine volume and did not increase fluid requirement during rest. In the second study, we examined the effects of menthol and caffeine on ventilatory and perceptual responses during simulated firefighting in the heat. Ten participants completed three trials, either with caffeine, menthol lozenges, or placebo. Contrary to the literature, menthol actually increased ventilatory loads (i.e., V_E , VO_2 ) and did not improve thermal or breathing comfort. The third study examined the effects of repeated dynamic exercise in the heat on mood and cognitive performance. Exercise in the heat substantially deteriorated mood states, but cognition was well maintained despite being at or near maximal heart rate, hypohydration, and hyperthermic state, suggesting possible coping mechanisms while working in multi-stressors situations. Neither caffeine nor menthol reduced the adverse impact of exercise-heat stress on mood. Current results provided information for military and occupational personnel performing duties in hot environments: (1) there was no evidence that caffeine ingestion in moderation would impair fluid balance during prolonged exercise in the heat and recovery; (2) perceptual and mood state degraded to a similar extent as physical performance; (3) caffeine and menthol exerted no ergogenic effect for firefighting in the heat. More efforts are needed to help those at-risk workers to cope with multi-stressors environments in order to maintain operational efficiency.
dc.format.extent 61 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Kinesiology
dc.title Physiological challenges in harsh environments: nutritional strategies for military and occupational operations
dc.type thesis
dc.type text University of Alabama. Dept. of Kinesiology Human Performance The University of Alabama doctoral Ph.D.

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


My Account