Estimating historical changes in physical activity levels

Objective; To compare activity levels between a simulated "historical" lifestyle and a "modern" lifestyle to try to validate earlier estimates of secular changes in activity. Design: Triaxial accelerometers (TRACMORs) were used to measure activity levels in a "historical" group of seven male actors who were paid to live like early Australian settlers at a theme park north of Sydney (eg, minimising the use of modern technology) for a week. Results were compared with those from a group of seven "modern" sedentary office workers. Results: Activity levels were up to 2.3 times greater in the historical group than the modern group. Calculations based on body weight and energy expenditure suggest the difference is the equivalent of walking up to 16 km per day more in the past than today. Conclusions: These findings accord with two previous estimates of changes in daily activity levels over time and suggest that recent public health guidelines for increasing physical activity may be inadequate.