The primary purpose of this study is to evaluate the effectiveness of using email prompts to attenuate the decrease of physical activity in adults during a winter season. In addition, the secondary purposes were (1) to evaluate the effectiveness of email prompts at increasing motivation towards physical activity and (2) to evaluate the awareness of the email campaign. Extension agents from the state of North Dakota (N=81) participated in a physical activity behavioral intervention study. Participants were grouped into an intervention group (N=39) that received bi-weekly physical activity electronic mail (email) prompts spread over 16 weeks, and a control group (N=42), that did not receive any intervention. Data on physical activity motivation and email message awareness were collected through standard questionnaires. Physical activity levels were measured with the International Physical Activity Questionnaires (IPAQ). Data were collected at two time points: mid-fall or pre-intervention and early spring or post-intervention. Over the winter season, both the control and intervention groups experienced an overall decrease in physical activity as measured by IPAQ (-317.0 MET-min/wk vs. -208.2 MET-min/wk, respectively). However, those in the intervention group who were able to recall the tag line were more active than controls. The significant difference in physical activity level between participants at the two extremes of the awareness levels indicates the potential efficacy of an email intervention campaign toward increasing physical activity. (Contains 4 tables.)