Relative risk (hazard ratio) of incident atrial fibrillation during 12 years of follow-up among 5,446 older adults according to usual walking habits (evaluated in quartiles), combining distance and pace of walking, adjusted for age, gender, race, enrollment site, education, smoking status, pack-years of smoking, coronary heart disease, chronic pulmonary disease, diabetes mellitus, alcohol use, and beta-blocker use. Diamonds represent risk estimates and bars represent 95% CIs, with the lowest category of walking habits as the reference group.