‘Activity-equivalent’ food labels are believed to encourage consumers to partake in exercise. This may occur by semantic priming, where featuring images of physical activity increases the mental accessibility of the concept of exercise, making it more ‘fluent’ and therefore more influential on people’s behaviour. We tested how the format of labels (image vs. text) and representation of energy (‘activity’ vs. ‘calorie) affected mental accessibility of exercise in a word-fragment completion task and participants’ behavioural intentions for exercise (N = 142). Participants exposed to calorie labels produced more exercise-related words and viewed an imagined exercise scenario as shorter and more enjoyable. Images led to higher intentions to exercise than text when they described activities but they led to lower intentions to exercise than text when they described calories. Findings suggest that activity labels do not trigger more activity related thoughts, but could increase exercise intentions only if presented in pictorial format.