The effect of hyperhydration on physiological and perceived strain during treadmill exercise in personal protective equipment
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Work in personal protective equipment (PPE) impairs thermoregulation causing cardiovascular stress, increased core body temperature, and hypohydration. We examined the effect of pretreating first responders performing treadmill exercise in PPE with an infusion of normal saline on physiological and perceptual strain. Ten (eight males, two females) euhydrated subjects performed treadmill exercise on two occasions wearing a chemical resistant coverall, air purifying respirator, butyl gloves, and heavy boots. During the hyperhydration session, normal saline was rapidly infused through an arm vein prior to donning PPE. Exercise duration and maximum core temperature did not differ between euhydrated and hyperhydrated conditions. Perceptual strain index (PeSI) was higher than physiological strain index (PhSI) in the euhydrated condition (P = 0.002) but neither index differed between the control and experimental conditions. Intravenous hyperhydration did not reduce physiological stress, increase exercise, or influence perceptual strain time when compared to the euhydrated condition in moderately fit individuals.
KeywordsThermoregulation Personal protective equipment Hydration Perceptual strain Physiologic strain
- Casa DJ, Maresh CM, Armstrong LE, Kavouras SA, Herrera JA, Hacker FT Jr, Keith NR, Elliott TA (2000) Intravenous versus oral rehydration during a brief period: responses to subsequent exercise in the heat. Med Sci Sports Exerc 32:124–133. doi:10.1097/00005768-200001000-00019 PubMedCrossRefGoogle Scholar
- Moran DS, Montain SJ, Pandolf KB (1998) Evaluation of different levels of hydration using a new physiological strain index. Am J Physiol 275(Regul Integr Comp Physiol 45):R854–R860Google Scholar
- Vokac Z, Kopke V, Keul P (1976) Physiological responses and thermal, humidity & comfort sensations in wear trials with cotton & polypropylene vests. Text Res J 46:30–38Google Scholar