Date of Graduation

1988

Document Type

Dissertation/Thesis

Abstract

This study was conducted to evaluate the lifting capabilities of individuals while wearing protective clothing in a hot environment and to investigate the behavior of the physiological stresses induced by the lifting process associated with those variables. In order to achieve the objectives of this research, two separate studies were conducted. The first part was an acclimatization and training program followed by a psychophysical experiment. Five male subjects, 28 to 31 years of age, participated in this study. They were heat acclimatized and trained for ten days prior to participation in the main experiment. The independent variables studied in the psychophysical experiment were: two levels of environmental temperature (22.2 and 31.1{dollar}\\sp\\circ{dollar}C WBGT), two lifting frequencies (1 and 5 lifts/min), and two types of clothing (light clothing and a protective clothing ensemble added over the light condition). The response variables for this experiment were: maximum acceptable weight of lift, heart rate, body temperature, oxygen consumption, ratings of perceived exertion and ratings of heat sensation. The training and acclimatization program resulted in significant increases in subject strength and maximal oxygen uptake (VO2 max) which was tested by applying a paired t-test for each comparison analysis. The average increase in subject static strength, maximum weight lifted, dynamic endurance, and the maximal oxygen uptake were 11.56%, 20.51%, 23.46%, and 6.19%, respectively. In addition, the subjects improved their acclimatization after six days of exposure to the heat sessions based on their physiological responses (i.e., heart rate and body temperature). The results of the main experiment were analyzed using the analysis of variance technique. All the main effects, of the dependent variables studied, were significant at either the one or five percent levels. In other words, the results showed that the weights selected by subjects at the higher environmental temperature, the higher lifting frequency, and the heavier level of clothing were significantly different from those selected at lower levels of the independent variables. Some of the interaction effects were also significant.

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