Two studies were conducted, one involving adoption of an exercise program and the other involving adherence to an aerobics exercise program. Consistent with action control theory, it was hypothesized that (a) subjective expected utility theory would predict exercise intentions but not exercise behavior in each study; (b) exercise adoption (Study 1) and attendance at an aerobics class (Study 2) would be predictable from the intentions regarding these behaviors expressed by action-oriented but not state-oriented subjects; and (c) subjects who had engaged in planning in regard to exercising would be more likely to adopt an exercise program (Study 1) and would exercise more frequently (Study 2). The findings provide some support for all three hypotheses. Implications of this research are discussed in regard to the distinction between decision making and decision implementation or action control; the relative usefulness of an action-control versus an expectancy-value approach for behavior involving complex decision implementation over a long period of time; the value of action orientation as a moderator of intention-behavior relationships; and the role of planning in exercise behavior.