Most adults do not achieve the levels of physical activity currently recommended for a healthy lifestyle. Population surveys suggest that there is a linear decline of activity levels with age, yet physical activity has many health benefits for older adults. If these are to be more widely adopted among older people, health policy and promotion require an understanding of the factors that influence decreasing activity with age. This study examined the patterns of physical activity of 699 participants in the West of Scotland Twenty-07 Study who were aged 60 years when interviewed in 1991 and followed up four to five years later. It examined the factors that influenced whether or not the subjects achieved currently recommended levels of activity, by applying random effects models with a seasonal adjustment. It was found that higher levels of physical activity associated with a healthier lifestyle, and that socio-economic factors played a minor role in determining the level of physical activity. A substantial amount of physical activity occurred at work but was lost by those who had retired, for while those who were not working were more physically active at home or at leisure than those in work, the majority of the sample did too little physical activity outside work to compensate for the loss of work-based activity. One conclusion is that health promotion initiatives that encourage people to become more physically active should be targeted at those who are about to retire.