Interactions between oxidative stress and cardiorespiratory fitness: old and new biomarkers

Enzymes, nonenzymatic total antioxidant capacity and reactive oxygen species-induced modifications on lipids, DNA and proteins are usually used to evaluate oxidative stress (OS) in humans. Asymmetric dimethylarginine (ADMA) has been suggested as a new OS marker. Antioxidant status may be improved by exogenous antioxidant intake or endurance training, which increases cardiorespiratory fitness (CRF). We reviewed studies on both OS markers and CRF. All markers were affected by age, gender, health, and exercise type. Exercise training with or without antioxidant interventions improved CRF and/or OS old markers, whereas more studies are needed for ADMA. CRF has high clinical significance and its measure should be included in the health assessment and in the redox status evaluated through OS markers.