| This dissertation includes an introduction (Chapter 1), a review of literature (Chapter 2) and two papers. In the first paper (Chapter 3), the relationship between age and exercise economy in adolescent girls, ages 13--18, was examined. In the second paper (Chapter 4), the reliability and validity of two methods for determining rating of perceived exertion (RPE) in adolescent girls was examined. Chapter five includes discussion of the relationships between exercise economy, RPE, and physical activity. All data included the same group of adolescent girls.;Exercise economy generally improves as a function of age, but the relationship was not found in this dissertation. Heart rate was found to be the best predictor of oxygen consumption (VO2) for three treadmill stages employed in the exercise protocol. Ventilation, body surface area, stride frequency, and aerobic capacity were other variables that helped predict VO2 during exercise. Study participants were fitter than average girls their age. The treadmill speeds chosen may have impacted the results by causing inefficient running mechanics, thus masking any relationship that may have existed.;The Borg category RPE scale and the OMNI RPE scale were tested for reliability and validity. Results showed that the OMNI scale was both more reliable and valid than the Borg scale for this sample of adolescent girls.;Study results infer a potential relationship between exercise economy, RPE, and physical activity. Although the number of participants was not large enough to perform inferential statistics, economy correlated fairly well with number of days of the week on which girls exercised vigorously for 20 minutes or more. Running economy also correlated well with OMNI RPE during stage 3 of the treadmill test. More research is needed before any directionality or causality can be determined from these potential relationships. |
