A Comparison Of Energy Expenditure And Prediction Equations During Walking Or Running Corrected For One Mile In Normal Weight And Overweight African American, Asian, And Caucasian Adults And Cross-Validation Of The Equations

Abstract

The prevalence of obesity is rapid across the world. Knowledge of the actual energy expenditure (EE) of walking and running can lead to a more precise exercise prescription which may lead to an obesity reduction or avoidance. Limited research has focused on EE during walking and running. Therefore, the aims of this study included developing ethnic based cross validated EE prediction equations for African American, Asian and Caucasian adults, and a multiple regression equation developed that included all three ethnic groups. Also, the energy expenditure among these three ethnic groups was compared. A total of 224 subjects, including 71 Caucasians, 68 African Americans and 85 Asians were recruited to test EE through indirect calorimetry. Analysis of variance (ANOVA) was used for over- all significance with post Hoc Scheffe test to compare EE in three groups (normal weight walkers, overweight walkers and runners). Multiple regression analysis was employed for EE prediction, and a dependent t-test and chow statistical test were used to cross-validate. The results shothat EE in runners was significantly higher than that in normal weight walkers in African Americans. When EE was expressed relative to body weight, similar difference was observed between walkers and runners in both African Americans and Asians. When EE was expressed relative to fat free mass, normal weight walkers expended less energy than runners, both among African Americans and Asians. Furthermore, EE in African Americans was significantly higher than that in Caucasians and in Asians. Three EE prediction equations were developed specifically for African Americans, Asians, and the three ethnic groups. Through cross-validation, all the three equations were valid and they were all recommended to apply for calculating EE during walking or running one mile. The overall prediction equation was: EE=0.978 bw-4.571 gender (m=1, f=2)+3.524 ethnicity (Caucasians=1, AA=2, Asians=3)+32.447 (r=0.77; see=12.5 kcalâ·mile-1)