The Influence of Fitness and Body Weight on Preferred Exercise Intensity

Abstract

PURPOSE: The purpose of this investigation was to determine the individual and combined effects of aerobic fitness and body weight on physiological responses, perceived exertion, and speed variables during self-selected steady-state treadmill (TM) walking in 60 healthy college-age women. METHODS: The women were placed into one of four categories based on body mass index (BMI) and fitness level, assessed by a graded TM test. Subjects walked continuously on a TM at a self-selected pace for 15 min at a 2.5% grade. The dependent variables were oxygen uptake (VO(2)), HR, percentage of maximal oxygen uptake (VO(2max)), percentage of HRmax (%HRmax), RPE for the overall body, TM belt speed, and total energy expenditure (EE). RESULTS: There were no significant interactions or body weight main effects for any of the dependent variables. However, lower-fitness subjects walked at a TM speed that resulted in a higher (P < 0.0005) VO(2max) (52.4 vs 39.56) than the higher-fitness subjects. CONCLUSION: These findings suggest that fitness, and not body weight, influences preferred exercise intensity as measured by VO(2max) during TM walking in college-age women. The self-selected walking speed did not result in an intensity, as determined by VO(2max), that is consistent with the enhancement of cardiorespiratory fitness for higher-fitness women regardless of body weight.