DOES ACCESS TO PHYSICAL ACTIVITY INFLUENCE OXIDATIVE STRESS OVER TIME?

Abstract

Oxidative stress has been shown to be related to factors such as advanced age, physical activity, physical inactivity, stress, and disease. PURPOSE The purpose of this study was to describe and distinguish selected health and oxidative stress biomarkers in rats that had different access to daily physical activity over approximately 75% of their maximum life span potential. METHODS 72 rats were randomly separated into three groups: 1) sedentary, 2) twice weekly physical activity, and 3) regular voluntary wheel running. Blood sampling occurred at age 4, 12, and 16 months. Body weight (BW, blood pressure (BP), and heart rate (HR) were measured bi-weekly. RESULTS Results showed that mean BW's were similar until week 10. Thereafter Group 3 BW was approximately 8–14% lower than both Groups 1 and 2 (F=3.90, p = .03). BP, HR, oxygen radical absorbance capacity and blood lipids did not differ between groups or over time. GSH,GSSG, and the ratio changed slightly over time, with Group 3 maintaining their levels and Group 1 changing towards greater oxidative stress by 16 months (F=4.94, p = .001). Tumor incidence did not appear to correlate with any groups, although size was larger in Group 1. CONCLUSION These data indicate that healthy animals did not show overt signs of disease, despite different access to physical activity, but signs of oxidative stress in physically inactive animals occurred as they aged.