http://precedings.nature.com/tags/Physical%20activity Recently posted documents tagged with 'Physical activity' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/2758/version/4 Objective: To investigate the best statistical models that describe the effect of physical activity on BMI.Design: Cross-sectional analyses of physical activity and BMI data. Subjects: 107 obese, overweight, and healthy college students (mean duration of physical activity for the normal, overweight, and obese students: 89, 59, and 24 months, respectively; mean BMI for the normal, overweight, and obese students: 21.61, 27.07, and 35.54 kg/m2, respectively).Measurements: Inverse linear, inverse logarithmic, and inverse logistics models were used to analyze survey data for physical activity (measured by both frequency and duration of exercise) and BMI. Gender, age, and physical intensity variables were also statistically controlled. Results: Coefficients of determination, r-squared, showed the inverse logarithmic model is more accurate in describing the effect of physical activity on BMI than is the inverse linear model. The inverse logistic method also showed physical activity affects BMI. Conclusions: Although the inverse logarithmic method can be used in some cases, the inverse logistic model seems to be theoretically and empirically best suited in describing the relationship between physical activity and body weight. http://precedings.nature.com/documents/2758/version/4 Wed, 01 Apr 2009 09:04:55 UTC The Relationship between Physical Activity and Body Mass Index: Issues in Model Specification hdl:10101/npre.2009.2758.4 2009-04-01 Gizachew Tiruneh Nature Precedings 2009-04-01T09:04:55Z Manuscript Developmental Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3004/version/1 Objective: To analyze whether changes in Physical Activity Index (PAI), sedentary time (ST; TV and PC use), and Body Mass Index (BMI) made a significant contribution to longitudinal changes in Physical Fitness (PF) of children and adolescents. Additionally, we analyzed interaction between baseline fitness level and changes in fitness. Methods: This is a three years longitudinal study of 345 high school students aged 11-19 years. Students were invited to perform tests from Fitnessgram battery for strength (curl-ups, push-up), and Cardiorespiratory fitness (20m-shuttle run). PAI and ST were evaluated using a standard questionnaire. Standardized scores of physical fitness tests were summed (ZPF). Changes over time, were calculated Δ1 (TP1 minus TP0), Δ2 (TP2 minus TP1), and Δtotal (TP2 minus TP0). Results: Changes in PAI were positively and independently associated with changes in ZPF in Δ1, Δ2, and Δtotal. No significant associations of ΔST and ΔZPF were found. ΔBMI was negative associated with ΔZPF in Δtotal. Participants with higher fitness levels at baseline were those who showed positive changes in PAI over Δtotal, decreased screen time and had the lowest increase in BMI over three years compared with those who were low-fit at baseline. Conclusions: Changes in PAI were the best predictor for changes in Fitness in children and adolescents in each year and over the three years of evaluation. BMI changes were associated with longitudinal changes in PF. http://precedings.nature.com/documents/3004/version/1 Tue, 31 Mar 2009 11:38:31 UTC Changes in Fitness, physical activity, fatness, and screen time: A longitudinal study in children and adolescents hdl:10101/npre.2009.3004.1 2009-03-31 Luisa Aires Nature Precedings 2009-03-31T11:38:31Z Manuscript Ecology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.2758.3 Objective: To investigate the best statistical models that describe the effect of physical activity on BMI.Design: Cross-sectional analyses of physical activity and BMI data.Subjects: 107 obese, overweight, and healthy college students (mean duration of physical activity for the normal, overweight, and obese students: 89, 59, and 24 months, respectively; mean BMI for the normal, overweight, and obese students: 21.61, 27.07, and 35.54 kg/m2, respectively).Measurements: Inverse linear, inverse logarithmic, and inverse logistics models were used to analyze survey data for physical activity (measured by both frequency and duration of exercise) and BMI. Gender, age, and physical intensity variables were also statistically controlled. Results: Coefficients of determination, r-squared, showed the inverse logarithmic model is more accurate in describing the effect of physical activity on BMI than is the inverse linear model. The inverse logistic method also showed physical activity affects BMI. Conclusions: Although the inverse logarithmic method can be used in some cases, the inverse logistic model seems to be theoretically and empirically best suited in describing the relationship between physical activity and body weight. http://dx.doi.org/10.1038/npre.2009.2758.3 Wed, 21 Jan 2009 20:21:03 UTC The Relationship between Physical Activity and Body Mass Index: Issues in Model Specification doi:10.1038/npre.2009.2758.3 2009-01-21 Gizachew Tiruneh Nature Precedings 2009-01-21T20:21:03Z Manuscript Developmental Biology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.2758.2 Objective: To investigate the best statistical models that describe the effect of physical activity on BMI.Design: Cross-sectional analyses of physical activity and BMI data.Subjects: 107 obese, overweight, and healthy college students (mean duration of physical activity for the normal, overweight, and obese students: 89, 59, and 24 months, respectively; mean BMI for the normal, overweight, and obese students: 21.61, 27.07, and 35.54 kg/m2, respectively).Measurements: Inverse linear, inverse logarithmic, and inverse logistics models were used to analyze survey data for physical activity (measured by both frequency and duration of exercise) and BMI. Gender, age, and physical intensity variables were also statistically controlled. Results: Coefficients of determination, r-squared, showed the inverse logarithmic model is more accurate in describing the effect of physical activity on BMI than is the inverse linear model. The inverse logistic method also showed physical activity affects BMI. Conclusions: Although the inverse logarithmic method can be used in some cases, the inverse logistic model seems to be theoretically and empirically best suited in describing the relationship between physical activity and body weight. http://dx.doi.org/10.1038/npre.2009.2758.2 Thu, 08 Jan 2009 10:54:31 UTC The Relationship between Physical Activity and Body Mass Index: Issues in Model Specification doi:10.1038/npre.2009.2758.2 2009-01-08 Gizachew Tiruneh Nature Precedings 2009-01-08T10:54:31Z Manuscript Developmental Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2758/version/1 Objective: To investigate the best statistical models that describe the effect of physical activity on BMI.Design: Cross-sectional analyses of physical activity and BMI data.Subjects: 107 obese, overweight, and healthy college students (mean duration of physical activity for the normal, overweight, and obese students: 89, 59, and 24 months, respectively; mean BMI for the normal, overweight, and obese students: 21.61, 27.07, and 35.54 kg/m2, respectively).Measurements: Inverse linear, inverse logarithmic, and inverse logistics models were used to analyze survey data for physical activity (measured by both frequency and duration of exercise) and BMI. Gender, age, and physical intensity variables were also statistically controlled. Results: Coefficients of determination, r-squared, showed the inverse logarithmic model is more accurate in describing the effect of physical activity on BMI than is the inverse linear model. The inverse logistic method also showed physical activity affects BMI. Conclusions: Although the inverse logarithmic method can be used in some cases, the inverse logistic model seems to be theoretically and empirically best suited in describing the relationship between physical activity and body weight. http://precedings.nature.com/documents/2758/version/1 Mon, 05 Jan 2009 20:35:56 UTC The Relationship between Physical Activity and Body Mass Index: Issues in Model Specification hdl:10101/npre.2009.2758.1 2009-01-05 Gizachew Tiruneh Nature Precedings 2009-01-05T20:35:56Z Manuscript Developmental Biology http://creativecommons.org/licenses/by/3.0/