Table 1. Classification by past physical activity.

	Past physical activity in teens
	−: none or almost none		+: some, a lot or too much
	Past physical activity in 30–40s		Past physical activity in 30–40s
	−	+	−	+
Past physical activity in 20s
−: none or almost none	None	Sometimes	Sometimes	Sometimes
+: some, a lot, too much	Sometimes	Sometimes	Sometimes	Consecutively