The French—and French women in particular—do not get enough physical activity. To encourage them to be more active, we need to address all the individual factors involved: confidence, which is the key driver of change; enjoyment, which motivates people to change their behavior; and also closely involving individuals in their own plans. We must also de-dramatize and remove the guilt associated with temporary breaks in activity, and set progressive, modest, and achievable goals. Finally, we must build a tailored program for each population. This article reviews the processes that lead to behavioral change, the barriers to change, and the factors that drive change, such as self-efficacy and social support.