Physical activity boosts brain-derived neurotrophic factor (BDNF), promoting neuroplasticity (Loprinzi and Frith, 2019), and consequently enhancing memory and learning (Piepmeier and Etnier, 2015), while also offering protection against Alzheimer’s and depression (Bjornebekk et al., 2005; Erickson et al., 2011; Liu and Nusslock, 2018). The gene discussed is BDNF; the disease is major depressive disorder.