Exercise-related affective changes are well documented across a variety of settings and populations. In addition to the stimulus properties of exercise itself, social environmental factors are thought to influence affective responses. One factor that may be associated with psychological responses to exercise is enjoyment. Individuals who enjoy exercise may exhibit more positive affective responses compared to those who enjoy exercise less. The purpose of this study was to examine whether exercise enjoyment was related to affective changes associated with an acute bout of exercise in a naturalistic setting. Study 1 used a categorical approach to assess affect and sampled college-aged female group fitness participants. Study 2 was based on a dimensional affect conceptualization and sampled corporate fitness participants. Across both studies, results revealed a significant decrease in negative affect and increase in positive affect following exercise. Enjoyment was positively related to increases in positive affect but unrelated to changes in negative affect.