Objective measurement of physical activity in a random sample of Saint-Petersburg inhabitants

Abstract

Background: World Health Organization (WHO) experts listed physical inactivity in leading risk factors for global mortality. Current research shows that only objective measurement of physical activity may provide accurate information on this parameter. The aim of our study was to assess the 7-day physical activity monitoring using triaxial accelerometers in a random sample of Saint-Petersburg inhabitants. Material and methods: As a part of all-Russian epidemiology survey ESSE-RF there was involved random sampling of 1600 Saint-Petersburg inhabitants (25–65 years) stratified by age and sex. After that a random sub-population of 100 subjects was selected. All subjects filled in questionnaire regarding physical activity, occupation, education and nutrition. Anthropometry (weight, height with body-mass index calculation, waist circumference) was performed. Actigraph GT3X+ (Actigraph LLC, USA) accelerometer and physical activity diary were used in order to evaluate physical activity monitoring for 7 days. Adequate levels of physical activity (PA) were defined as more than 10 000 steps/day and at least 150 minutes/week of moderate and vigorous physical activity (MVPA) in bouts of 10 minutes or more. Results: 1/2 of subjects were physically active according to steps, and 1/3 according to MVPA time criteria. No gender, occupation or body composition differences were revealed in physically active and inactive subjects. Almost 50% of physically active subjects had balanced workweek-weekend PA profile, and the same criterion is true only for 13% of subjects in inactive group. In both groups the same peaks of MVPA were revealed — at 8.00–9.00 and 18.00–19.00, which are typical transportation time, but in active group these peaks were significantly higher. According to PA diaries, in most of cases physical inactivity was related to the usage of private or public transport. Conclusion: Triaxial PA-monitoring shows, that 40–60% of subjects were physically inactive, and 150-min MVPA goal can easily be achieved by only increasing walking time during transportation peaks. The physical inactivity was not determined by the type of occupation, sex or age, instead it was mainly influenced by the usage of cars in the morning and evening transportation time, rather than walking.