Table 2 The criteria of physical activity levels

High physical activity

Meet either of the following 2 criteria

1 Have all kinds of high intensity physical activities ≥3 days, and total weekly physical activity level ≥ 1500MET·min/week.

2 Have physical activities ≥7 days, and total weekly physical activity level ≥ 3000MET·min/week.

Moderate physical activity

Meet either of the following 3 criteria

1 At least 20 minutes of high intensity physical activity each day.

2 At least 30 minutes of moderate intensity physical activity and/or walking each day.

3 Have physical activities ≥5 days, and total weekly physical activity level ≥ 600MET·min/week.

Low physical activity

Meet either of the following 2 criteria

1 No activity was reported.

2 Some activities were reported but did not meet the above criteria of high and moderate physical activity.