Levels and Patterns of Objectively Assessed Physical Activity
Levels and Patterns of Objectively Assessed Physical Activity
This study compares levels and patterns of objectively assessed physical activity in Sweden and the United States by using identical accelerometer metrics. Data of adult respondents with ≥4 days with ≥10 hours per day of accelerometer wear from Sweden (2001–2002, n = 1,172) and the United States (2003–2004, n = 2,925) were compared. Outcomes reported by age and body mass index within sex include accelerometer counts per minute and amounts and bouts of activity at different intensities, that is, sedentary, low, lifestyle, and moderate or higher intensity physical activity. The mean counts per minute were 375 (95% confidence interval (CI): 360, 390) and 377 (95% CI: 363, 391) for Swedish and US males, respectively, and 363 (95% CI: 347, 379) and 298 (95% CI: 289, 307) for Swedish and US females. Older respondents and those with higher body mass index had lower activity levels. Swedish and US males spent 36 (95% CI: 34, 38) and 33 (95% CI: 31, 36) minutes per day, and Swedish and US females spent 32 (95% CI: 29, 34) and 19 (95% CI: 17, 21) minutes per day in moderate or higher intensity physical activity. Older Swedes were more active in moderate or higher intensity activities than were older US respondents. However, younger Swedish males had more sedentary behavior time than did younger US males. These results provide a framework for international comparisons of physical activity levels and patterns, and they represent strong evidence for the importance of investment in objective measurement of physical activity.
Increasing physical activity time and decreasing sedentary time have significant health benefits. Comparisons of physical activity levels among different countries can motivate and guide global patterns of investment in health promotion, provide better evidence for ecologic and comparative analyses, and generate novel insights into the demographic, environmental, and cultural correlates of physical activity and sedentary behaviors.
To date, international comparisons of physical activity levels in adults have been based on self-report. These measures are frequently used both to monitor physical activity at the population level and to evaluate physical activity interventions due to their practicality, low cost, modest participant burden, and general acceptance. Significant differences among countries in physical activity and sedentary behavior have been reported from studies using self-report data. However, in one study, Sweden and Finland were the most active in Europe, while in the Eurobarometer Study Sweden had the lowest prevalence of "sufficiently active" and Finland was near the median. Such differences may be because different instruments are measuring different aspects of physical activity, or they may be due to one or more sources of error known to influence self-report. Challenges to the validity of self-reported data on physical activity include differential levels of social desirability bias and the cognitive challenge of recalling behaviors from the past.
Because of the limitations of self-report, interest in objective physical activity monitoring has increased. Accelerometers can provide minute-by-minute registration of diverse activities. Researchers in Sweden and the United States have reported accelerometer data for nationally representative samples. Results of these studies were originally reported with somewhat different demographic categories, inclusion criteria, and activity cutoff levels. The 2 studies used the same accelerometer and similar study protocols, presenting a unique opportunity for an international comparison of objective measures of physical activity.
The aim of this study was to describe the level and pattern of objectively assessed physical activity, in terms of average overall levels, and time (total accumulated or in bouts) spent in physical activities of different intensities (sedentary, low, lifestyle, and moderate or higher intensities) among adults in Sweden and the United States. Tabulation of multiple physical activity levels by using identical metrics for the 2 countries allows a robust comparison of results from the 2 countries and an interesting contrast to past studies based on self-report.
Abstract and Introduction
Abstract
This study compares levels and patterns of objectively assessed physical activity in Sweden and the United States by using identical accelerometer metrics. Data of adult respondents with ≥4 days with ≥10 hours per day of accelerometer wear from Sweden (2001–2002, n = 1,172) and the United States (2003–2004, n = 2,925) were compared. Outcomes reported by age and body mass index within sex include accelerometer counts per minute and amounts and bouts of activity at different intensities, that is, sedentary, low, lifestyle, and moderate or higher intensity physical activity. The mean counts per minute were 375 (95% confidence interval (CI): 360, 390) and 377 (95% CI: 363, 391) for Swedish and US males, respectively, and 363 (95% CI: 347, 379) and 298 (95% CI: 289, 307) for Swedish and US females. Older respondents and those with higher body mass index had lower activity levels. Swedish and US males spent 36 (95% CI: 34, 38) and 33 (95% CI: 31, 36) minutes per day, and Swedish and US females spent 32 (95% CI: 29, 34) and 19 (95% CI: 17, 21) minutes per day in moderate or higher intensity physical activity. Older Swedes were more active in moderate or higher intensity activities than were older US respondents. However, younger Swedish males had more sedentary behavior time than did younger US males. These results provide a framework for international comparisons of physical activity levels and patterns, and they represent strong evidence for the importance of investment in objective measurement of physical activity.
Introduction
Increasing physical activity time and decreasing sedentary time have significant health benefits. Comparisons of physical activity levels among different countries can motivate and guide global patterns of investment in health promotion, provide better evidence for ecologic and comparative analyses, and generate novel insights into the demographic, environmental, and cultural correlates of physical activity and sedentary behaviors.
To date, international comparisons of physical activity levels in adults have been based on self-report. These measures are frequently used both to monitor physical activity at the population level and to evaluate physical activity interventions due to their practicality, low cost, modest participant burden, and general acceptance. Significant differences among countries in physical activity and sedentary behavior have been reported from studies using self-report data. However, in one study, Sweden and Finland were the most active in Europe, while in the Eurobarometer Study Sweden had the lowest prevalence of "sufficiently active" and Finland was near the median. Such differences may be because different instruments are measuring different aspects of physical activity, or they may be due to one or more sources of error known to influence self-report. Challenges to the validity of self-reported data on physical activity include differential levels of social desirability bias and the cognitive challenge of recalling behaviors from the past.
Because of the limitations of self-report, interest in objective physical activity monitoring has increased. Accelerometers can provide minute-by-minute registration of diverse activities. Researchers in Sweden and the United States have reported accelerometer data for nationally representative samples. Results of these studies were originally reported with somewhat different demographic categories, inclusion criteria, and activity cutoff levels. The 2 studies used the same accelerometer and similar study protocols, presenting a unique opportunity for an international comparison of objective measures of physical activity.
The aim of this study was to describe the level and pattern of objectively assessed physical activity, in terms of average overall levels, and time (total accumulated or in bouts) spent in physical activities of different intensities (sedentary, low, lifestyle, and moderate or higher intensities) among adults in Sweden and the United States. Tabulation of multiple physical activity levels by using identical metrics for the 2 countries allows a robust comparison of results from the 2 countries and an interesting contrast to past studies based on self-report.
