<h3>Introduction</h3> Thereis growing evidence for the benefits of exercise to the aging brain. Exercise promotes brain function, improves brain metabolism, cerebrovascular flow, and neuroplasticity. All these contribute to cognitive reserve and prevention of late life cognitive decline. Conversely, a sedentary lifestyle has been shown to increase all causes of mortality, double the risk of cardiovascular and metabolic diseases which are significant risk factors to stroke and vascular cognitive decline. Inactivity also increases the risk for late life depression and anxiety. Despite the known benefits of exercise and long existing recommendations to promote physical activity, 60-85% of the world's population lead an inactive lifestyle. Sedentary lifestyle carries high risk for late life cognitive decline and reduced brain health amongst additional vascular and metabolic consequences. Inactivity has become one of the most difficult to treat health risk factors. Efficient promotion of physical activity is of high importance to the elderly population. Nevertheless, high prevalence of sedentary lifestyle indicates that the implementation of exercise recommendations is unsuccessful. The field of Behavioral Economics (B/E) studies motivation and decision-making and may be able to shed light on common behaviors such as inactivity. Given the known risks of sedentary lifestyle, physical inactivity would be defined by Behavioral Economists as an "irrational behavior". This approach may suggest a new and valuable method in mitigating inactivity. This review aims to present concepts of B/E related to health behavior and establish the vital need for collaboration. Efficient promotion of physical activity is crucial in prevention and treatment of late life cognitive decline and depression. <h3>Methods</h3> We searched MEDLINE, MEDLINE RCTs, PsycINFO, EMBASE without a date filter. Studies that explore the impact of exercise on the brain, including neurophysiology and neurocognitive function were reviewed and evaluated. Additionally, studies exploring human motivation and decision making from the field of B/E were evaluated in the context of healthcare management. Epidemiological data for the prevalence of late life depression, aging, cognitive decline, and the prevalence of sedentary lifestyles is appraised. <h3>Results</h3> Studiesacross various domains of healthcare and behavioral economics have been reviewed. There is well studied scientific evidence for benefits of exercise in improving brain health, such as increased cerebrovascular flow, improved neuroplasticity, increase in neurotrophic factors, neurotransmitters, and more. Moreover, exercise is already a longstanding healthcare recommendation for prevention of late life cognitive decline and depression. High prevalence of sedentary lifestyle suggests that healthcare recommendations for physical activity are ineffective and should be more efficiently implemented. Review of B/E literature supports a novel approach: the definition of certain health behaviors as "predictably irrational", meaning that the individual's decision is not necessarily benefitting the person. For example, one of the principles in behavioral economics is "optimism bias": the assurance that our present behavior will probably not have a negative result in the future. As a result of optimism bias, people underestimate the future health consequences of sedentary behavior at present. Another concept is "loss aversion": the discomfort of loss is more dominant than the comfort of the chance to benefit. Loss aversion may explain why a person would not choose to exercise: it is perceived as an immediate loss, with no benefit. Exercise is effortful and involves discomfort, while the future health benefit is perceived as a non-existent at present. The present loss (discomfort of exercise) combined with no immediate health benefit may explain the common choice of staying inactive. These examples illustrate some of the difficulties in implementing an active lifestyle. <h3>Conclusions</h3> Exercise is highly beneficial in maintaining brain health, including prevention of late life cognitive decline and late life depression. Motivation to exercise is expected to be high given these benefits, though most of the population does not meet the physical activity recommendations criteria. Effective promotion of exercise is substantial for the aging population in prevention of late life cognitive decline and depression. High prevalence of sedentary lifestyle suggests ineffectiveness in current promotion of physical activity. Further research is required to adapt Behavioral Economics concepts in healthcare and develop novel and more efficient strategies in promotion of physical activity. <h3>This research was funded by</h3> There was no funding of any kind and no financial support to this research project.