Exhaustive exercise can cause subclinical inflammation to heart, since it is an oxidative tissue that works continuously. The effect of exhaustive exercise on left and right ventricles (LVs, RVs) may be different. It is claimed that paraoxonase-1 (PON1), an antioxidant enzyme, has a cardioprotective effect on oxidative stress. Rats were separated as; non-exercised controls (Con), those euthanized immediately after (E-0) and 24 hours after exhaustive exercise (E-24). Cardiac troponin-I (cTnI), total antioxidant status (TAS), total oxidant status (TOS), PON1 activities and histological findings in LV and RV of the exhausted rats were evaluated. TAS and PON1 levels were lower in LVs compared to RVs of all groups. TOS levels were high in LVs compared to RVs of all groups. In LVs, TAS levels decreased significantly in E-0 group while PON1 activity decreased in E-0 and E-24 groups compared to controls. In LVs, TOS levels decreased significantly in E-0 and E-24 groups, but in RVs decrease was seen only in E-0 group. cTnI levels increased significantly in E-0 group, and decreased to control levels in E-24 group. Considering the histological and biochemical findings, exhaustive exercise affected the heart to the maximum during/just after exhaustion, and LV was influenced more than RV.