“…It has been shown that the activation of brainderived neurotrophic factor and its receptor TrkB signaling pathway is involved in the neuroprotective effect of exercise against brain injury (Gerecke et al, 2012;Wu et al, 2011). On the other hand, reports demonstrate that long-term moderate exercise induces low level of reactive oxygen species (ROS), which may activate the endogenous antioxidant defense system (Elokda et al, 2010;Somani et al, 1995), though highintensity acute exercise increases oxidative stress and vulnerability to brain injury (Aguiar et al, 2010;Teixeira et al, 2009). The induction of adaptive antioxidant defense by regular exercise has therefore been suggested to be able to prevent oxidative stress-associated aging (Navarro et al, 2004) and neurodegeneration (Cechetti et al, 2012;Garcia-Mesa et al, 2012).…”