Global Physical Activity Questionnaire
Physical activity was measured at baseline, 3 months, and 6 months using the Global Physical Activity Questionnaire (GPAQ). Physical activity was categorized as either moderate or vigorous. We defined vigorous (eg, running or lifting heavy loads) and moderate (eg, brisk walking or carrying light loads) physical activities as activities that cause large and small increases in breathing or heart rate for at least 10 minutes continuously, respectively. We asked participants whether (yes or no) they were engaged in vigorous or moderate physical activity, the number of days in a week in which they were engaged in this activity, and the amount of time (in h and min) they spent on a typical day engaging in this activity at work, during travel and during leisure time. We reported total metabolic equivalent (MET) minutes per week for each participant where 1 minute of moderate activity and 1 minute of vigorous activity are equivalent to 4 MET minutes and 8 MET minutes, respectively [