Aerobic Training Prevents The Development Of Metabolic Abnormalities Induced By Chronic Stress, But Not Abnormal Circulating Levels Of Noradrenaline And Serotonin

The chronic mild and unpredictable stress (CMS) protocol induces insulin resistance, dyslipidemia, oxidative stress and endothelial dysfunction in rats. Regular physical exercise is an effective non-pharmacological tool for the treatment of disorders induced by stress. The aim was to evaluate the role of physical training on hormonal and metabolic changes triggered by CMS. Forty male Sprague-Dawley rats were randomized into: Control, Stress, Exercise, Exercise + Stress, submitted to CMS protocol or to 8-week treadmill training (50-70% of the maximal exercise test). In the 4 th , 5 th and 6 th wk, the animals were submitted to CMS protocol over seven days, repeating the procedures for 3 consecutive weeks. Two weeks after last stressor stimulus, blood and left ventricle were collected. Physical performance of animals submitted to the CMS was lower when compared to control animals, and physical training has not been able to alleviate this loss (p vs. Exercise: 1.4±0.1; Exercise + Stress: 1.3±0.1; Control: 1.4±0.0 ng/mL), insulin resistance index (Stress: 9.2±0.3 vs. Exercise: 7.1±0.2; Exercise + Stress: 5.8±0.2; Control: 8.1±0.2) and serum free fatty acids (Stress: 311.9±10.0 vs. Exercise: 193.0±16.7; Exercise + Stress: 251.6±14.16; Control: 190.1±17.3 mg/dL, p vs. Exercise: 0.6±0.1; Exercise + Stress: 0.5±0.0; Control: 1.3±0.1 pg/g, p vs. Control: 165.1±27.1 pg/mL) and serotonin (Stress: 1296.0±47.0; Exercise: 1196.0±68.1; Exercise + Stress: 1736.0±60.12 vs. Control: 619.8±79.6), which remained high in the groups submitted to the CMS (pu003e0.05). The results show that exercise improves metabolic losses triggered by CMS, but not the but not abnormal circulating levels of noradrenaline and serotonin, and suggest that physical training must be prescribed with caution to stressed individuals.