Fig. 1From: Heritability and genetic etiology of habitual physical activity: a twin study with objective measuresHabitual physical activity (HPA) and physical activity level (PAL) as a function of PPARD genotype. a, b Shows the associations with rs2267668, C-D with rs2076168. Associations were obtained using linear regression and are shown for twins (a, c) and unrelated individuals (b, d) assuming an additive model. The number of individuals within a genotype-group is indicated in the bars. Data shown are means ± SD. § P < 0.01, *P < 0.05, D: P = 0.09Back to article page