This study examined changes in involvement in physical exercise and the motives for and obstacles to participation over an 8-year period in a representative sample of senior residents of Jyväskylä. Finland. The participants were noninslitulionalized seniors age 65-84 years at baseline in 1988. The most common form of physical exercise was walking for fitness. In men, participation in supervised exercise classes and performing calisthenic exercises at home increased over the follow-up. In women, physical exercise generally declined. The most important reason quoted for nonparticipation at both baseline and follow-up was poor health (65-88%). Among those who reported participation in supervised physical exercise, the most important motives were health promotion (80%) and social reasons (40-50%). The main obstacles were poor health (19-38%) and lack of interest (28-26%). It is an important challenge to remove obstacles to participation in physical activity in old age and to give older people every opportunity to get involved.