| 1. |
- Stenevi-Lundgren, S., et al.
(författare)
-
The increase in physical performance and gain in lean and fat mass occur in prepubertal children independent of mode of school transportation. One year data from the prospective controlled Pediatric Osteoporosis Prevention (POP) study
- 2009
-
Ingår i: Archives of Public Health. - : Springer Science and Business Media LLC. - 0778-7367 .- 2049-3258. ; 67:2, s. 88-96
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this 12-month study in pre-pubertal children was to evaluate the effect of school transportation on gain in lean and fat mass, muscle strength and physical performance. Methods: Ninety-seven girls and 133 boys aged 7-9 years from the Malmö Pediatric Osteoporosis Prevention Study were included. Regional lean and fat mass were assessed by dual energy X-ray absorptiometry, isokinetic peak torque of knee extensors and flexors by a computerised dynamometer and physical performance by vertical jump height. Level of physical activity was assessed by accelerometers. The 12-month changes in children who walked or cycled to school were compared with changes in those who travelled by bus or car. Results: There were no differences in baseline or annual changes in lean or fat mass gain, muscle strength or physical performance between the two groups. All children reached the internationally recommended level of 60 minutes per day of moderate or high physical activity by accelerometers. Conclusion: The choice of school transportation in pre-pubertal children seems not to influence the gain in lean and fat mass, muscle strength or functional ability, probably as the everyday physical activity is so high that the mode of school transportation contributes little to the total level of activity.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Dencker, Magnus, et al.
(författare)
-
Daily physical activity related to aerobic fitness and body fat in an urban sample of children.
- 2008
-
Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 1600-0838 .- 0905-7188. ; 18, s. 728-735
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates associations between objectively measured daily physical activity vs aerobic fitness and body fat in children aged 8-11 years. A cross-sectional study of 225 children aged 7.9-11.1 years was performed. Abdominal fat mass (AFM) and total body fat (TBF) were quantified by dual-energy x-ray absorptiometry. TBF was calculated as percentage of total body mass (BF%). Body fat distribution was calculated as AFM/TBF. Aerobic fitness was measured by indirect calorimetry during a maximal cycle ergometer exercise test. Daily physical activity was assessed by accelerometers for 4 days and daily accumulation of moderate-to-vigorous and vigorous activity was calculated. Significant relationships (P<0.05) existed for vigorous activity vs ln BF% (r=-0.40), ln AFM (r=-0.35), TBF/AFM (r=-0.22) and aerobic fitness (r=0.38), whereas moderate-to-vigorous activity displayed weaker relationships (-0.22, -0.18, -0.12 NS, and 0.25). Multiple regression analyses with inclusion of possible confounders concluded that vigorous activity was independently related to aerobic fitness and ln BF% or ln AFM. Moderate-to-vigorous activity was only independently related to aerobic fitness. In this population, low daily accumulation of vigorous activity was, already in children aged 8-11 years, associated with more body fat and lower aerobic fitness. A similar relation was not found for daily accumulation of moderate-to-vigorous activity.
|
|
| 6. |
- Dencker, Magnus, et al.
(författare)
-
Daily physical activity related to body fat in children aged 8-11 years
- 2006
-
Ingår i: Journal of Pediatrics. - : Elsevier BV. - 1097-6833 .- 0022-3476. ; 149:1, s. 38-42
-
Tidskriftsartikel (refereegranskat)abstract
- Objective To evaluate the association between objectively measured daily Study design Cross-sectional, observational, study of 248 children aged 7.9 to 11.1 years. Abdominal fat mass and total body fat mass were measured by dual-energy X-ray absorptiometry. Daily physical activity was assessed by accelerometers for 4 days. Results Total body fat expressed as a percentage of body mass was inversely related to minutes of vigorous physical activity per day, for all children r = -0.38 (P < .05). Children, both boys and girls, in the highest quartile of body fat performed on average 12 minutes less vigorous activity per day compared with their counterparts in the lowest quartile. Multiple regression analysis revealed that independent factors for body fat were number of minutes of vigorous activity per day and sex. Conclusion Low physical activity can be a contributing factor in childhood obesity. Only longitudinal studies, however, can give more definitive information about the relation between daily physical activity and obesity.
|
|
| 7. |
- Dencker, Magnus, et al.
(författare)
-
Objectively measured daily physical activity related to cardiac size in young children.
- 2009
-
Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 1600-0838 .- 0905-7188. ; Aug 5, s. 664-668
-
Tidskriftsartikel (refereegranskat)abstract
- Training studies in children have suggested that endurance training can give enlargement of cardiac dimensions. This relationship has not been studied on a population-based level in young children with objective methods. A cross-sectional study was made of 248 children (140 boys and 108 girls), aged 8-11 years, from a population-based cohort. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured with echocardiography and indexed for body surface area (BSA). Physical activity was assessed by accelerometry, and the duration of vigorous physical activity per day (VPA) was calculated. Acceptable accelerometer and echocardiography measurements were obtained in 228 children (boys=127, girls=101). Univariate correlations between VPA and LVDD were indexed for BSA in boys (r=0.27, P<0.05) and in girls (r=0.10, NS). Multiple regression analysis showed that independent factors for LVDD, indexed for BSA for boys, were age and VPA. LA indexed for BSA was not related to physical activity variables in either gender. No clear relationship exists between cardiac size and daily physical activity in children aged 8-11 years. This suggests that significant cardiac remodelling due to volume exposure secondary to a high amount of physical activity begins later in life.
|
|
| 8. |
- Dencker, Nils, et al.
(författare)
-
The solvability and subellipticity of systems of pseudodifferential operators
- 2009
-
Ingår i: Advances in Phase Space Analysis of Partial Differential Equations - In Honor of Ferruccio Colombini's 60th Birthday. - Boston : Birkhäuser Boston. - 2374-0280 .- 1421-1750. - 9780817648602 ; 78, s. 73-94
-
Konferensbidrag (refereegranskat)abstract
- The paper studies the local solvability and subellipticity for square systems of principal type. These are the systems for which the principal symbol vanishes of first order on its kernel. For systems of principal type having constant characteristics, local solvability is equivalent to condition (Ψ) on the eigenvalues. This is a condition on the sign changes of the imaginary part along the oriented bicharacteristics of the real part of the eigenvalue. In the generic case when the principal symbol does not have constant characteristics, condition (Ψ) is not sufficient and in general not well defined. Instead we study systems which are quasi-symmetrizable, these systems have natural invariance properties and are of principal type. We prove that quasi-symmetrizable systems are locally solvable. We also study the subellipticity of quasi-symmetrizable systems in the case when principal symbol vanishes of finite order along the bicharacteristics. In order to prove subellipticity, we assume that the principal symbol has the approximation property, which implies that there are no transversal bicharacteristics.
|
|
| 9. |
|
|
| 10. |
|
|
