SIRT1 and Alzheimer disease: The signaling events linking physical activity with reduction in severity of AD include activity of the Wnt pathway, along with influences that suppress aberrant neuronal apoptosis or decrease amyloid β accumulation through its enzymatic degradation and improvement of synaptic plasticity and neurogenesis [28–30], or by increasing the expression of sirtuin-1/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (SIRT-1/PGC-1α) signaling, therefore inhibiting amyloid β production [31].