Current exercise guidelines encourage the daily accumulation of lifestyle activities, such as stair climbing. Although several studies show that visual prompts can increase stair usage, there has been little systematic assessment of the messages employed. Some of the messages used in previous interventions represent general descriptions of stair climbing (e.g. 'free exercise'), while others emphasize specific consequences of stair use (e.g. 'keeps you fit'). Twelve hundred structured interviews were conducted in order to establish which type of message is more persuasive. In addition, half of the interviewees were told that the messages were true, in order to assess how validating messages may influence their persuasive appeal. Results suggest that messages focussing on specific consequences are more persuasive than those providing general descriptions and that validating the information presented in stair-climbing interventions may increase their efficacy. Previous messages may not, therefore, have demonstrated the full potential of stair climbing as a model for increasing population activity levels.