Health, Exercise, and Sports Sciences ETDs

Publication Date

4-10-1969

Abstract

Nineteen men between the ages of twenty-four and thirty-seven were trained for eight weeks to determine the effect of improved cardio-respiratory fitness on basal metabolic rate and body composition. The hypothesis was that a change in active tissue mass brought about by exercise would not be accompanied by a change in basal metabolic rate. Two measurements of body composition were made, lean body mass and fat-free weight. Lean body mass was estimated by the potassium-40 technique at the Los Alamos Scientific Laboratory, Los Alamos, New Mexico. Fat-free weight was estimated by hydrostatic weighing. The total lung volume of each subject was measured by nitrogen washout so that accurate determinations of residual lung volumes could be made during hydrostatic weighing. Basal metabolic rate was measured using an open circuit Douglas bag method on at least two consecutive mornings or until values were obtained which were within ten milliliters of oxygen consumption per minute. These tests were then averaged and accepted as the basal metabolic rate of each subject. Maximum oxygen uptake was measured on a motor driven treadmill before and after the training period to determine if fitness changes had occurred. Significant changes were made by the group in maximum oxygen uptake, basal metabolic rate, and fat-free weight. Changes in lean body mass as measured by potassium-40 were not statistically significant; however, seventeen of the nineteen subjects increased in percent lean body mass, and twelve of the nineteen increased in kilograms of lean body mass. A significant correlation at the one percent level of confidence was found between lean body mass and basal metabolic rate and between fat-free weight and basal metabolic rate. A z-test for similarity of correlations indicated that the pretest correlations were not significantly different from the posttest correlations. The similarity of pre and posttest regression lines indicated that the prediction value of lean body mass and fat-free weight on basal metabolic rate was changed very little following a change in cardio-respiratory fitness brought about by exercise. Although the slope of the regression line was changed very little following exercise, the intercept was elevated. This indicated that each kilogram of active tissue required more oxygen following exercise than was required before exercise. A multiple regression equation was computed which included grams potassium and maximum oxygen uptake along with the variables of fat-free weight and lean body mass. The multiple correlation was not significantly better than the single correlations using fat-­free weight and lean body mass alone. The hypothesis that a change in active tissue mass brought about by exercise would not be accompanied by a change in basal metabolic rate was accepted. Basal metabolic rate did increase more than could be explained by increases in active tissue. However, the similarity of pre and posttest correlations may indicate that some of the change in basal metabolic rate could be accounted for by changes in active tissue mass.

Document Type

Dissertation

Language

English

Degree Name

Physical Education, Sports and Exercise Science

Level of Degree

Doctoral

Department Name

Health, Exercise, and Sports Sciences

First Committee Member (Chair)

William Asmer Bynum, Jr.

Second Committee Member

James Gordon Cooper

Third Committee Member

Marvin LeRoy Riedesel

Fourth Committee Member

Lloyd Robert Burley

Download

Share

COinS