Acute Changes In Sedentary Behavior Following Aerobic Exercise In Overweight And Obese Females

Abstract

Introduction: As the obesity epidemic continues to progress, the importance of participating in regular physical activity and maintaining a healthy diet is being emphasized more than ever. Exercise is often recommended to create a daily energy deficit in hopes that this deficit will result in weight loss. The reality is that weight loss due to an exercise induced energy deficit is typically less than predicted. It is hypothesized that the body attempts to counter balance the exercise induced energy deficit by reducing daily energy expenditure through an increase in daily sedentary behavior. Only a few studies have attempted to investigate this compensatory and many of these studies did not use technology that was specifically designed to measure sedentary behaviors. This study will utilize the activPal accelerometer which is designed to measure sedentary behaviors. Purpose: The purpose of this study was to compare acute changes in daily sedentary behavior between overweight (BMI ≥ 25) and obese (BMI ≥ 30) sedentary, college-age women over a 24-hour period, following either a 200 or 400 kcal bout of aerobic exercise (walking). Methods: Thirty-five participants completed three trials: control (no exercise), 200 kcal of exercise, and 400 kcal of exercise. The exercise consisted of walking on a treadmill at 70% of their heart rate reserve. The order of these trials were randomized. For the 200 and 400 kcal sessions, indirect calorimetry was used to measure energy expenditure. For 24 hours following each trial, changes in sedentary behavior were recorded using the activPal accelerometer. Data was analyzed using a repeated measures ANOVA. Results: There were no significant differences between the control, 200 kcal, or 400 kcal trials for sit/lie time (p = 0.230, 574.8 ± 145.5, 614.8 ± 108.4, 573.4 ± 150.9 min, respectively), standing time (p = 0.062, 231.4 ± 117.8, 185.5 ± 80.1, 219 ± 84.2 minutes respectively) or steps (p = 0.928, 7797.3 ± 3788.9, 7965.0 ± 3423.8, 7701.8 ± 3682.7 steps respectively). Conclusion: The results of this study show that daily sedentary behaviors in overweight/obese college age females does not significantly change following a single bout of aerobic exercise.