Table 3.

Distribution of vigorous physical activity variables*

	First examination  (1999–2003)		Second examination  (2010–2014)
	n/N	%	n/N	%
Frequency
≤1 a month	1559/3910	39.9	1499/3896	38.5
1–3 times a week	1833/3910	46.9	1736/3896	44.6
≥4 times a week	518/3910	13.2	661/3896	17.0
Duration
≤30 min	1595/3880	41.1	1559/3845	40.5
1–3 hours	1675/3880	43.2	1514/3845	39.4
≥4 hours	610/3880	15.7	772/3845	20.1
Active
≥2 times a week and ≥1 hour	1450/3878	37.4	1635/3843	42.5
Changes between first (1999–2003) and second (2010–2014) examinations
Inactive at both examinations			1637/3816	42.9
Active at first examination but inactive at second examination			551/3816	14.4
Inactive at first examination but active at second examination			752/3816	19.7
Active at both examinations			876/3816	23.0

*There was a significant change in the distributions of all physical activity parameters (frequency, duration and active status) across the two examinations (McNemar-Bowker test, all P values <0.001).

n, number of cases; N, total available sample size.