Fig. 1From: Association between education and future leisure-time physical inactivity: a study of Finnish twins over a 35-year follow-upCategorization of leisure-time physical activity (LTPA) at baseline (1975/1981), in 1990 and in 2011, and in analysing long-term inactivity both in the whole cohort (n = 5254) and in the long-term LTPA discordant twin pairs. A = active (> 1.5 MET h/day), I = inactive (≤ 1.5 MET h/day)Back to article page