Estimated activity patterns in British 45 year olds: cross-sectional findings from the 1958 British birth cohort

Objective: To investigate patterns of, and associations between, physical activity at work and in leisure time, television viewingand computer use.Subjects: 4531 men and 4594 women with complete plausible data, age 44�45 years, participating in the 1958 British birthcohort study.Methods: Physical activity, television viewing and computer use (hours/week) were estimated using a self-completequestionnaire and intensity (MET hours/week) derived for physical activity. Relationships were investigated using linearregression and w2tests.Results: From a target sample of 11 971, 9223 provided information on physical activity, of whom 75 and 47% providedcomplete and plausible activity data on work and leisure time activity respectively. Men and women spent a median of 40.2 and34.2 h/week, respectively in work activity, and 8.3 and 5.8 h/week in leisure activity. Half of all participants watched televisionfor X2 h/day, and half used a computer for o1 h/day. Longer work hours were not associated with a shorter duration ofleisure activity, but were associated with a shorter duration of computer use (men only). In men, higher work MET hours wereassociated with higher leisure-time MET hours, and shorter durations of television viewing and computer use. Watching moretelevision was related to fewer hours or MET hours of leisure activity, as was longer computer use in men. Longer computeruse was related to more hours (or MET hours) in leisure activities in women.Conclusions: Physical activity levels at work and in leisure time in mid-adulthood are low. Television viewing (and computeruse in men) may compete with leisure activity for time, whereas longer duration of work hours is less influential. To changeactive and sedentary behaviours, better understanding of barriers and motivators is needed