Understanding the factors that motivate health-enhancing physical activity has considerable merit given
the role of this lifestyle behaviour in combating disease and promoting quality of life. The purpose of this
article is to provide a broad overview of research investigating participation issues in exercise from the
perspective of self-determination theory (SDT; Deci & Ryan, 2002). Evidence informing the application
of SDT to the study of motivational issues in exercise is reviewed around three central questions: (a) Does
the quality of motivation regulating exercise behaviour “matter”?, (b) How important are basic psychological
needs within exercise contexts?, and (c) Can contextual variables be manipulated to create
adaptive environments for exercise? The available evidence is supportive of many propositions set forth
within SDT by Deci and Ryan’s (2002). Future avenues for exercise motivation research are offered
based on the available evidence with a view to addressing unresolved issues and advancing SDT’s
development.