Exercise protects against METH-induced oxidative stress in brain capillaries. Mice were subjected to voluntary wheel running for 5 weeks. Control (i.e., sedentary) mice did not have access to wheels. At the end of the exercise regimen, mice were injected with METH (10 mg/kg, i.p.) for 24 h. Superoxide levels were determined in isolated brain capillaries by dihydroethidine (DHE). The images are representative data from three independent experiments and the quantified results (mean ± SEM) are depicted in the form of bar graphs. ***As compared to the respective controls at p < 0.001. †††Data in the exercised group are significantly different as compared to the respective treatment in the sedentary group at p < 0.001.