Genetic Influences on Individual Differences in Exercise Behavior during Adolescence

Table 2

Prevalence (95% confidence intervals between parentheses) of exercise participation in the different age groups as a function of sex.

	13-14 yr		15-16 yr		17–19 yr
	Boys	Girls	Boys	Girls	Boys	Girls
Sedentariness	20% (17%–22%)	31% (28%–33%)	24% (21%–26%)	31% (29%–34%)	27% (24%–31%)	38% (35%–40%)
Moderate exercise	40% (39%–41%)	45% (45%–46%)	35% (35%–36%)	45% (44%–45%)	31% (30%–31%)	38% (38%–39%)
Vigorous exercise	40% (37%–44%)	24% (21%–26%)	41% (38%–44%)	24% (21%–27%)	41% (38%–46%)	24% (21%–27%)