Skeletal muscle has the ability to adapt and remodel after various stresses. Reactive oxygen is continuously generated in skeletal muscle cell and during physical activity. This plays an important role with transcription factors which modulate gene expression of antioxidants. A training induced oxidative stress reduction caused by an adaptation of the antioxidant defense mechanism in skeletal muscle and in plasma of human and animal models has been observed in several recent studies. Results suggest that an accumulation of intense exercise (intense period of training and/or duration) can provoke an increase in oxidative stress. It is largely undefined which type, extent and intensity of training should be implemented in basic programs in order to achieve the most efficient activation of the antioxidative/cell-protective capacity.