The aging process does not progress at the same speed between individuals (Hertzog, Kramer, Wilson, & Lindenberger,2008). The following two categories of factors moderate the speed of aging and explain a large part of the variance in the cognitive performance of individuals throughout the life span: genetic factors and lifestyle factors. Genetic factors are related to genetic polymorphisms that can influence cognitive phenotypes. Lifestyle factors notably include the amount of physical activity (PA) practiced every week throughout a long period (e.g., 1 year) and the dietary habits. This chapter aims to specify the relationships among the following four variables: aging, inhibitory control, the genetic polymorphism of the brain-derived neurotrophic factor (BDNF) gene located at codon 66, and PA. In the second and following section, we focus on inhibitory control and show its crucial role in cognition and daily living. In the third section, we discuss on the unity and diversity of inhibitory processes. In the fourth section, we present the two main categories of effortful inhibitory control and their brain substrates. In the fifth section, we address the deleterious effect of aging on this important executive function. In the sixth section, we explain the role of neurotrophins, and more particularly the brain-derived neurotrophic factor (BDNF), in brain plasticity and brain health, and present the gene that affects its trafficking and secretion. In the seventh and eighth parts, we review the role of the genetic polymorphism of this gene in cognition during aging. Finally, in the ninth section, we examine the moderating role of physical activity and eating behaviors in the relationship between BDNF polymorphism and cognitive aging.