INTRODUCTION
Acute physical exercise induces augmented generation of reactive
oxygen species (ROS) in muscle and in other organs (1–3).
Because of that, it has been generally accepted over the past 20 y
that increasing the concentrations of antioxidants within a muscle
cell should provide greater protection against these oxidizing
agents and should reduce fatigue (4 –7). However, the functional
significance of exercise-induced oxidative stress is open to discussion.
Results from several laboratories indicate that ROS are
signals that serve to up-regulate the expression of a number of