Date of Award
Master of Arts
Human Performance and Health Education
Health, Physical Education & Recreation
Dr. Roger Zabik
Dr. Mary Dawson
Dr. Patricia Frye
Masters Thesis-Open Access
The purpose was to compare the effect of dietary supplementation using two different energy bars, the PRBar and the PowerBar, ingested 1 hour before exercise, on the exercise metabolism of endurance athletes. Four dependent variables were measured: respiratory exchange ratio (R), oxygen consumption (VO2), rating of perceived exertion (RPE), and blood glucose. Independent variables were bars (2), trials (2), and sample time. Sample times occurred at 5-min intervals for R, VO2, and RPE. Blood glucose was sampled before exercise, at 15 min and 25 min during exercise, and after exercise. Subjects completed four 35-min training runs, two after consuming each of the energy bars, in a random order on separate days. All testing was completed within 3 weeks. Subjects ran at an exercise intensity equal to 65% to 75% of their maximal oxygen consumption. Results indicated significant differences existed (a) between the energy bars for both R and RPE, (b) between sample times for all dependent variables, and (c) between trials for RPE. Also, a significant interaction effect, Bars x Trials, occurred for VO2. It was concluded that although the significant decrease in R and significant increase in RPE supported an increase in fat metabolism during exercise when subjects supplemented with the PRBar, the lack of significant changes in VO2 and blood glucose levels across training runs indicated a mixed result. Also, the practical significance of the changes in R and RPE was questioned.
Witt, Chad F., "Effects of the PRBar and PowerBar on Fat Metabolism" (1998). Masters Theses. 4581.