The purpose of this systematic review was to provide a comprehensive analysis of the available clinical trials analyzing, in seniors, the effect of interval aerobic training (IAT) and continuous aerobic training (CAT) on peripheral brain-derived neurotrophic factor (BDNF) concentration. We identified 14 randomized or not-randomized intervention studies published up to January 2017 through a computer-assisted search (PUBMED, Pedro, and Science direct data bases). The five trials considering IAT and the nine considering CAT totalized 988 individuals (age range: 58.1-77 years). The parameters of aerobic training (AT) protocol in terms of frequency and intensity are the primary determinants of the BDNF response to AT. The interpretation of the relationship between AT and BDNF signaling pathway was very challenging when specific health conditions were taken into consideration. This was more particularly true with mild cognitive impairment or depressive symptoms. These findings argue in favor of a generalization of the practice of AT and show that the type of training is not the main determining factor of the increase in BDNF level, which results more from the combination of several factors such as intensity and frequency of sessions, duration of programs, and also some genetic determinant coding for BDNF protein. All these factors have to be carefully addressed in future researches in that field. Thus, further researches are still necessary to better the signaling pathway by which AT contributes to better health outcomes.