IGF1 and Anxiety: Additionally, physical activity and exercise induce widespread neurobiological adaptations and could reduce anxiety-like behaviors, enhance neurogenesis via promoting IGF1 and BDNF activity (Droste et al., 2003; Schoenfeld, Rada, Pieruzzini, Hsueh, & Gould, 2013), and reduce ACTH hormones and corticosterone levels (Hare, Beierle, Toufexis, Hammack, & Falls, 2014; Wang, Chen, Lin, Jhong, & Chen, 2014).