COMPARISON BETWEEN HIGH INTENSITY INTERVAL TRAINING AND MODERATE INTENSITY CONTINUOUS TRAINING ON MARKERS OF OXIDATIVE STRESS AND ENERGY METABOLISM IN THE SKELETAL MUSCLE OF HIGH-FAT DIET RATS

Aim: We evaluated energy metabolism and oxidative stress adaptations induced by high-intensity interval training (HIIT) versus moderate intensity continuous training (MICT) in the gastrocnemius muscle of high-fat diet (HFD) fed rats. Main methods: Animals received 8 weeks of HFD or normal diet (ND), followed by 9 weeks of HFD or ND and the two physical exercise interventions (HIIT or MICT). The gastrocnemius muscle was selected for the oxidative stress and energy metabolism analysis. Key findings: Although the body weight of experimental groups did not change, HFD caused significantly higher amounts of visceral adipose tissue (VAT) and decreased pyruvate kinase (PK), cytochrome c oxidase (COX) and glutathione peroxidase (GSH-Px) activities. MICT protocol increased catalase (CAT), superoxide dismutase (SOD) and GSH-Px, decreased thiobarbituric acid reactive substances (TBA-RS), increased citrate synthase (CS), succinate dehydrogenase (SDH), COX and complex II. The HIIT protocol reduced VAT, increased CAT and SOD activities, decreased TBA-RS, increased the protein carbonylation, PK, CS and COX, but did not up regulate SDH or complex II. Significance: In summary, MICT was more efficient in maintaining the cellular redox state and HIIT in improving energy metabolism, then both modalities promoted benefits aiming metabolic health and muscular redox state in skeletal muscle.