The initial survey for EPIC-Norfolk was conducted between 1993 and 1997 (First Health Check, 1HC), recruiting 25,639 residents of the region of East Anglia, attending 35 general practice surgeries situated in the county of Norfolk (Day et al., 1999). The sample for this analysis included 15,672 participants with self-reported measures of physical activity from the Second Health Check conducted between 1998 and 2000 (2HC, Follow-up 2, from here referred to as ‘baseline’ for the purposes of this analysis) and a postal questionnaire administered between 2006 and 2009 (from here referred to as ‘follow-up’). This allowed the examination of change in physical activity over time.