Physical activity in midlife and telomere length measured in old age

Abstract Physical activity has been associated with alterations in telomere length, a potential indicator of biological aging, but several inconsistencies exist. Our aim was to investigate the associations between physical activity in midlife and leukocyte telomere length (LTL) measured in old age in the Helsinki Businessmen Study, Finland. At entry, in 1974, 782 men (mean age 47) completed a questionnaire about their physical activity and this was collapsed into 3 categories: low (n = 148), moderate (n = 398) and high physical activity (n = 236, 7 of whom had a competitive activity level). After 29-year follow-up in 2003, mean LTL and the proportion of short (