BACKGROUND: Standing is often classified as light-intensity physical activity, with potential health benefits compared with sitting. Standing is, however, rarely captured as an independent activity. To better understand free-living standing behaviour at a population level, we incorporated a gold standard postural allocation technique into a national cohort study. METHODS: Participants (n=5412, aged 46.8±0.7 years) from the 1970 British Cohort Study were fitted with a water-proofed thigh-mounted accelerometer device (activPAL3 micro) worn 24 hours continuously over 7 days (90.7% provided at least 3 full days). We examined the correlates of free-living standing during waking hours. RESULTS: Total daily standing time averaged 4.6±1.5 h/d, accounting for 29% of waking hours, which was largely (98.7%) accumulated in bouts lasting less than 30 min. In mutually adjusted models, male sex, obesity, diabetes, professional occupation, poor self-rated health and disability were associated with lower device-measured standing times. CONCLUSION: Middle-aged people in Britain spent a surprisingly large proportion of the day in activities involving standing. Standing merits attention as a health-related posture and may represent a potential target for public health intervention
