Invited Guest Editorial: Envisioning the next fifty years of research on the exercise-affect relationship

Objectives: To summarize the major accomplishments of research on the relationship between exercise and affect over the past five decades and to outline an expanded research agenda for the future. Design: Literature review. Method: Illustrative and historically significant publications on the exercise affect link were examined. Results: The main accomplishments over the past fifty years include (a) a growing recognition that exercise can have a positive and clinically meaningful influence on affect, with possible implications for the treatment of mental health problems, and (b) the incorporation of affect in exercise prescription guidelines as a method of monitoring exercise intensity and a possible determinant of adherence. Emerging research directions include efforts to understand (a) the role of affect in exercise behavior, (b) the cognitive and biological mechanisms of affective responses, (c) individual differences in affective responses, including the contribution of genetic polymorphisms, (d) the application of exercise in the treatment of addictions through the process of "hedonic substitution," (e) the possible connection between affective responses and cognitive function, and (f) the processes underlying the sense of fatigue. Conclusions: The study of the exercise affect relationship remains one of the most vibrant and prolific areas of research within exercise psychology. The last few years, in particular, have witnessed a dramatic expansion of the research agenda, addressing questions of great societal importance, increased interdisciplinary interest, and direct implications for practice. (C) 2013 Elsevier Ltd. All rights reserved.