Decreased Activity of the Hypothalamic-Pituitary-Adrenal Axis after Acute Aerobic Exercise in Obese Women

Abstract The increase of cortisol hormone and blood pressure indicates the active Hypothalamic-Pituitary-Adrenal axis (HPA-axis) and Sympathetic-Adreno-Medullary-axis (SAM-axis). Someone with obesity tends to have a more active HPA-axis and SAM-axis. Exercise is proclaimed as an effective model to reduce the HPA-axis and SAM-axis activities. This study aims to describe the HPA-axis and SAM-axis activities on the moderate-intensity aerobic. The participants of this study were 20 obese female teenagers aged 20 to 24 years old with sufficient physical fitness. They were divided into three groups of CTL (n=7, control group), IAE (n=7, interval time aerobic exercise) and CAE (n=7, continuously aerobic exercise). IAE was carried out with moderate-intensity running followed by active recovery through low-intensity running with five repetitions. It was carried out for 35 minutes. The CAE was carried out with moderate-intensity continuously running for 30 minutes. Both IAE and CAE were completed using treadmills. The HPA-axis was estimated using cortisol hormone indicator, while the cortisol hormone was measured using ELISA Kit. The SAM-axis was examined using the heart response. The data were analyzed using a One-Way ANOVA test with SPSS version 21. The results suggest significant different cortisol hormone secretion between before and after the moderate-intensity interval time and continuously aerobic exercise (P ≤ 0.01). Different blood pressure and heartbeat were also observed before and after the aerobic (P ≤ 0.01). Moderate-intensity interval time and continuously aerobic exercise reduces cortisol hormone secretion, blood pressure, and heartbeat, thus, it lessens the HPA-axis and SAM-axis activities. Keywords: HPA-axis, SAM-axis, Aerobic exercise, Obesity