Changing ideas about "fitness and fatness" and relationship to behavior in those who believe physical activity is only necessary for those overweight or obese.


This research examined if information regarding the importance of exercise for everyone, regardless of body weight, could change explicit bias toward normal weight and sedentary persons (to be rated less fit and healthy) and attentional bias to sedentary and exercise-related stimuli in participants who believe exercise is only necessary if one is overweight or obese. The relationship of changes in explicit bias, attentional bias, and attitudes, subjective norms, self-efficacy, perceived behavioural control, and intentions  to physical activity behaviour (self-report and pedometer measures) over one week was evaluated. Psychology students who strongly endorsed the item “I only need to exercise if I am overweight or obese” and were inactive were randomly assigned to an exercise-reading (n=39) or control (n = 39) group.  At pretest participants completed a primed Stroop task and questionnaires (explicit bias, social cognitive variables, and physical activity). They then read information about either exercise or studying, followed by a thought listing procedure and posttest Stroop and explicit bias measures. They were given a pedometer to record steps over one week, after which they reported back and again completed the Stroop task and questionnaires. Participants in the experimental group reported significantly more physical activity and steps. Change in explicit bias and self-efficacy predicted changes in self-report physical activity. Participants who increased their physical activity also had increased self-efficacy but reported that sedentary normal weight people were more fit and healthy. There was a significant change in attentional bias for exercise words.  By answering questions about exercise, participants may have been more oriented toward exercise. They may also have felt healthy, despite not being very active, and thus have rated sedentary people as more healthy. An important contribution of this research is identifying a group for targeted information and identifying information that may be useful in changing their behavior.