The American Cancer Society (ACS) publishes Nutrition and Physical ActivityGuidelines to serve as a foundation for its communication, policy, and community strategies and ultimately, to affect dietary and physical activity patterns among Americans. These Guidelines, published every 5 years, are developed by a national panel of experts in cancer research, prevention, epidemiology, public health, and policy, and as such, they represent the most current scientific evidence related to dietary and activity patterns and cancer risk. The ACS Guidelines include recommendations for individual choices regarding diet and physical activity patterns, but those choices occur within a community context that either facilitates or interferes with healthy behaviors. Community efforts are essential to create a social environment that promotes healthy food choices and physical activity. Therefore, this committee presents one key recommendation for community action to accompany the four recommendations for individual choices to reduce cancer risk. This recommendation for community action recognizes that a supportive social environment is indispensable if individuals at all levels of society are to have genuine opportunities to choose healthy behaviors. The ACS Guidelines are consistent with guidelines from
The purpose of this investigation was to assess the accuracy of the COSMED K4 b2 portable metabolic measurement system against the criterion Douglas bag (DB) method. During cycle ergometry on consecutive days, oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), and respiratory exchange ratio (R) were measured at rest and during power outputs of 50, 100, 150, 200, and 250W. No significant differences (P > 0.05) were observed in VO2 between the K4 b2 and DB at rest and at 250W. Though the K4 b2 values were significantly higher (P<0.05) than DB values at 50, 100, 150, and 200 W, the magnitude of these differences was small (0.088, 0.092, 0.096, and 0.088 L x min(-1), respectively). VCO2 and VE values from the K4 b2 were significantly lower than the DB at 200 and 250 W, while no significant differences were observed from rest through 150W. The slight overestimation of VO2 (50-200 W) combined with the underestimation of VCO2 (200 and 250W) by the K4 b2 resulted in significantly lower R values at every stage. These findings suggest the COSMED K4 b2 portable metabolic measurement system is acceptable for measuring oxygen uptake over a fairly wide range of exercise intensities.
Background:National and international strategies to increase physical activity emphasize environmental and policy changes that can have widespread and long-lasting impact. Evidence from multiple countries using comparable methods is required to strengthen the evidence base for such initiatives. Because some environment and policy changes could have generalizable effects and others may depend on each country’s context, only international studies using comparable methods can identify the relevant differences.Methods:Currently 12 countries are participating in the International Physical Activity and the Environment Network (IPEN) study. The IPEN Adult study design involves recruiting adult participants from neighborhoods with wide variations in environmental walkability attributes and socioeconomic status (SES).Results:Eleven of twelve countries are providing accelerometer data and 11 are providing GIS data. Current projections indicate that 14,119 participants will provide survey data on built environments and physical activity and 7145 are likely to provide objective data on both the independent and dependent variables. Though studies are highly comparable, some adaptations are required based on the local context.Conclusions:This study was designed to inform evidence-based international and country-specific physical activity policies and interventions to help prevent obesity and other chronic diseases that are high in developed countries and growing rapidly in developing countries.
The purposes of this study were: (a) to determine the optimal categorization of an instrument measuring women's exercise perseverance and barriers using the Rasch analysis and (b) to examine urban women's exercise perseverance and barriers. A 23-item barrier instrument with five response categories was administered to 479 women from a metropolitan area. The data analysis started from collapsing the original five adjacent categories into three and four categories and 11 sets of original and collapsed data were analyzed using the Rasch rating scale model. The model-data fit, category and separation statistics, and parameter estimates provided by Rasch analyses were used to determine the optimal categorization of the instrument. Instead of the original five-category construct, which had a disordered internal construct, a collapsed three-category construct (i.e., Very Often/Often, Sometimes/Rarely, and Never) was found to have the optimal categorization. The time barrier domain was found to be the most severe barrier domain, but the barrier "lack of self-discipline" was the most severe individual barrier. Rasch calibration provides a new way to construct an instrument with optimal categorization, to describe the nature of barrier items and the respondents' attribute being measured, and to develop a practical and informative scoring sheet.
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