The interrelationships of oxygen intake capacity, strength, body composition and physical working capacity.
Creators: name: Miki, Kenneth Koji
Publisher: name: University of British Columbia
Year: 2011

description: The purpose of this study was to determine the interrelationships between oxygen intake capacity, strength, body composition and physical working capacity, as measured by the Sjostrand PWC₁₇₀ test. The subsidiary problems were: 1. to determine what statistical procedure, i.e., zero order correlations, first order partial correlations, twenty-second order partial correlations or stepwise multiple regression analysis, gave the greatest insight into the physiological relationships between the variables selected for this study, 2. to determine the form in which the variables investigated have the most meaning biologically, i.e., as raw scores, as scores divided by body weight, or as scores divided by fat free weight, and 3. to determine the accuracy of calculating PWC₁₇₀ by graphical estimation of the best fitting straight line as compared with the computer calculated values obtained by the least squares regression method. Fifty-four subjects from the School of Physical Education and Recreation at the University of British Columbia participated in this study. The Sjostrand PWC₁₇₀ test was conducted to estimate physical working capacity, and an "all out" ride on the bicycle ergometer was administered to determine maximum oxygen intake values. Body density was determined by the hydrostatic weighing technique, and body fat was calculated by the formula derived by Keys and Brozek. A comprehensive strength test was also conducted on all the subjects. The statistical analysis of the data were obtained through the Computing Center at the University of British Columbia (Program - Triangular Regression Package). A zero order correlation analysis was conducted to assess the accuracy of the graphic method in the calculation of PWC₁₇₀ scores. A zero order correlation analysis was also conducted to investigate the interrelationships between all the variables when no variables were held constant. Two first order correlation analysis were conducted to investigate the interrelationships between all the variables when body size was held constant, i.e., body weight and fat free weight, respectively. A twenty-second order correlation matrix was obtained to investigate the interrelationship between two variables when all others were held constant. Three stepwise multiple regression analysis were conducted to determine the interrelationships between each of the dependent variables (PWC₁₇₀ kpm per min; PWC₁₇₀ kpm per min per kg body weight; PWC₁₇₀ kpm per mln per kg fat free weight) with two or more of the independent variables. Within the limitations of the study, it was concluded that the conventional graphic technique appeared to be an accurate method to estimate the best fitting straight line in the calculation of the PWC₁₇₀ scores. The results obtained in this study appeared to support the use of performance scores divided by fat free weight as the most biologically meaningful way to express performance capacity data. This appeared to be the preferred method for comparisons of individuals' "true" abilities or capacities without regard to differences in body size or body fat. Consequently, the procedure appeared to be very appropriate for use in normative tables. The first order partial correlations of non-ratio variables with fat free weight held constant appeared to be the best statistical procedure in providing Insight into physiological relationships between oxygen intake capacity, strength and physical working capacity (PWC₁₇₀ kpm per min). The zero order correlation analysis, first order partial correlation analysis and stepwise multiple regression analysis showed the following apparent relationships to exist between the variables explored in this study: i) Fat free weight appeared to be the common factor in the relationships between many of the variables in this study, ii) Oxygen intake in liters per min was significantly related to physical working capacity (PWC₁₇₀ kpm per min) in zero order and first order correlation analysis (significant at the 0.01 level of confidence). In the stepwise multiple regression analysis, oxygen intake in liters per minute did not contribute to the prediction of PWC₁₇₀ kpm per min, but it would have been the best single predictor in the absence of fat free weight. Oxygen intake in ml per min per kg body weight was the best predictor of PWC₁₇₀ kpm per min per kg body weight. It was also the best predictor of PWC₁₇₀ kpm per min per kg fat free weight, but this appeared to be due to the smaller dispersions of oxygen intake in ml per min per kg fat free weight. iii) Strength of the right leg extensor muscles correlated significantly with PWC₁₇₀ kpm per min in zero order and first order correlation analysis (significant at the 0.05 level of confidence). This variable made a small contribution to the prediction of physical working capacity in all three stepwise multiple regression analysis, iv) Body density correlated significantly with PWC₁₇₀ kpm per min per kg body weight in zero order correlation analysis and with FWC₁₇₀ kpm per min when body weight was statistically held constant (significant at the 0.01 level of confidence). It contributed to the prediction of FWC₁₇₀ kpm per min per kg body weight only slightly less than oxygen intake ml per min per kg body weight. Thus, it appeared that in this study, leaner subjects appeared to attain higher PWC₁₇₀ kpm per min per kg body weight scores.