This cohort has the advantage of being very large with approximately 184,000 US adults and over 19,000 deaths for whom detailed information on time spent sitting and physical activity was collected at baseline.
- women who reported sitting for more than 6 hours during their time versus less than 3 hours a day had an approximately 40% higher all-cause death rate, and men had an approximately 20% higher death rate. This association was independent of the amount of physical activity.
- The combination of both sitting more and being less physically active (>6 hours/day sitting and <24.5 MET-hours/week physical activity) was associated with a 94% and a 48% increase in all-cause death rates in women and men, respectively, compared with those who reported sitting the least and being most active (<3 hours/day sitting and ≥52 MET-hours/week physical activity).
MET scores assigned for various activities include the following: 3.5 for walking, 7.0 for jogging/running, 7.0 for lap swimming, 6.0 for tennis or racquetball, 4.0 for bicycling/stationary biking, 4.5 for aerobics/calisthenics, 3.5 for dancing, 3.0 for gardening/mowing/planting, 2.5 for heavy housework/vacuuming, 3.0 for heavy home repair/painting, and 2.5 for shopping.
MET (Metabolic Equivalent): The ratio of the work metabolic rate to the resting metabolic rate. One MET is defined as 1 kcal/kg/hour and is roughly equivalent to the energy cost of sitting quietly. A MET also is defined as oxygen uptake in ml/kg/min with one MET equal to the oxygen cost of sitting quietly, equivalent to 3.5 ml/kg/min. https://sites.google.com/site/compendiumofphysicalactivities/
Patel AV, Bernstein L, Deka A et al (2010) Leisure time spent sitting in relation to total mortality in a prospective cohort of US adults. Am J Epid 172:419–429
