Stability and change in physical activity in old age: the role of changes in disability.

The objective was to examine whether stability and change in physical activity in older men and women are influenced by (1) changes in disability and by (2) social relations and psychological well-being. The study is based on baseline, 3 and 4.5 year follow-up data on 917 older men and women. Changes in physical activity were measured through self-reported frequencies of vigorous physical activity at the three measurement points. The analyses were carried out for two outcomes-decline in physical activity versus sustained high level of physical activity (from high to low) and sustained low physical activity versus improvement in physical activity (from low to high). The main results were: older adults with onset of tiredness or continuous tiredness in daily activities during 4.5 years are more likely to have a concurrent decline in their physical activities during the same period. Older adults with onset of need of help and sustained need of help are more likely to have a decline in physical activities or to sustain a low level of physical activities during the same period. The associations between the psychosocial factors and change in physical activity are attenuated by the concurrent changes in disability. The present study supports that health promotion projects should be aware that development of tiredness and continuous tiredness are strongly related to a decline in physical activity and that onset of and sustained need of help are strongly associated with both a decline in and sustained low physical activity.