Promoting health benefits is necessary but insufficient to foster sustained engagement in physical activity (PA).
Our formal decision-making model explains why health benefits hold a weak subjective value.
In this model, expected health benefits are jointly discounted by effort-discounting, delay-discounting, and beliefs distortion.
In contrast, positive affective experiences toward PA can reduce the perception of effort, provide more immediate consequences, and strengthen beliefs about health benefits.
Because affective experiences have the potential to tip the balance in favor of PA over sedentary alternatives, they should be at the core of PA promotion.