In attempts to better understand factors that contribute to the initiation and continuation of exercise behavior, increasing research attention has focused on the pivotal role of affective responses to exercise. To further explore this topic, this study examined anticipated and remembered affective responses in a self-paced moderate-intensity running protocol with healthy adults. Participants (N = 25; 13 females; M<sub>age</sub> = 29.2; SD = 4.34 years) performed two trials of 20 min running at a self-determined moderate intensity on a treadmill. The trials were performed 48 hr apart, and measures of anticipated affective response and remembered affect were collected prior to and after each trial. The findings indicated that participants generally anticipated a pleasant response to the moderate-intensity running activity. Anticipated affective responses recorded immediately prior to commencing running were lower than anticipated affect measured 24 hr in advance. Additionally, participants remembered their exerciserelated affect to be pleasant, although it fluctuated over time and declined during a period that extended to 48 hr postexercise. Mounting evidence suggests that training programs aiming to promote the sustainability of exercise behavior can benefit from considering temporal fluctuations of affective responses when developing exercise prescription, supervision, and maintenance.