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The aim was to study long-term effects on motor skills and school performance of increased physical education (PE). All pupils born 1990-1992 from one school were included in a longitudinal study over nine years. An intervention group ( n = 129) achieved daily PE (5 × 45 min/week) and if needed one extra lesson of adapted motor training. The control group ( n = 91) had PE two lessons/week. Motor skills were evaluated by the Motor Skills Development as Ground for Learning observation checklist and school achievements by marks in Swedish, English, Mathematics, and PE and proportion of pupils who qualified for upper secondary school. In school year 9 there were motor skills deficits in 7% of pupils in the intervention group compared to 47% in the control group ( P < 0.001), 96% of the pupils in the intervention group compared to 89% in the control group ( P < 0.05) qualified for upper secondary school. The sum of evaluated marks was higher among boys in the intervention group than in the control group ( P < 0.05). The sum of marks was also higher in pupils with no motor skills deficit than among pupils with motor skills deficits ( P < 0.01), as was the proportion of pupils who qualified for upper secondary school (97% vs 81%, P < 0.001). Daily PE and adapted motor skills training during the compulsory school years is a feasible way to improve not only motor skills but also school performance and the proportion of pupils who qualify for upper secondary school. [ABSTRACT FROM AUTHOR]

Mechanical load through physical activity has been shown to be one of the best stimuli to increase the bone strength. This effect of mechanical load accounts for both the accrual of bone mineral and structural skeletal adaptations. Exercise prescription also includes a 'window of opportunity' in the late pre- and early peri-pubertal period, where exercise is supposed to insert the most obvious beneficial effects, even if physical activity provides recordable skeletal benefits during all growth. There is also evidence that benefits in bone mass and bone structure obtained by mechanical load during growth may be maintained at advanced age. The notion that former male athletes have lower fracture risk than expected by age, support this view. Physical activity could therefore to be recommended at growth and adolescence as one possible strategy to reduce the future burden of fragility fractures. [ABSTRACT FROM AUTHOR]

Intervention studies have shown that high-intensity training programs with duration of 1-3 years can influence bone mass in post-menopausal women. We wanted to investigate whether moderate physical activity could be associated with reduced post-menopausal bone loss also in the long-term perspective. We evaluated changes in bone mass and bone structure by repeated single-photon absorptiometry measurements of the distal forearm in 91 moderately physically active and 21 inactive women, categorized according to information from questionnaires, from menopause and on average 25 years onwards. Data were calculated with analysis of variance and analysis of covariance tests and presented as means with 95% confidence interval. There were no group differences in bone mass or bone structure at menopause. The mean annual loss in bone mineral content was 1.2% (1.1, 1.3) in the physically active and 1.6% (1.3, 1.8) in the inactive women (after adjustment for menopausal age P = 0.02) and the mean decline in a strength index based on bone mass and bone structure was 0.7% (0.6, 0.8) in the physically active and 1.2% (0.8, 1.5) in the inactive women ( P = 0.004). There were no group differences in the changes in bone structure. Physical activity is also in a long-term perspective associated with reduced post-menopausal bone loss. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Physical inactivity is hypothesized to be a contributing factor in the development of a variety of diseases. Recommendations for an adequate level of physical activity have been proposed. There are few studies in which the physical activity in children has been objectively assessed. The purpose of this study was to estimate objectively the level of physical activity in Swedish children. Materials and methods: We studied 248 children (140 boys and 108 girls) aged 7.9–11.1 years from Malmö, Sweden. Physical activity was measured with accelerometers. Children were instructed to wear the accelerometers for 4 days. The mean daily activity was expressed as the mean counts per minute of recording. The time that the child spent performing moderate or vigorous activity was calculated by using previously established cutoff points. Results: The mean daily activity was higher in boys than in girls, 751±243 vs 618±154 counts/min ( P<0.001). All children fulfilled the recommendation for moderate physical activity for 60 min or more per day. Ninety-two percent of the boys and 86% of the girls performed vigorous activity, for 20 min or more per day. Conclusion: All children, aged 8–11 years, who participated in this study reached the recommended level of physical activity, with boys being more active than girls. [ABSTRACT FROM AUTHOR]

Physical activity is favorable for peak bone mass but if the skeletal benefits remain and influence fracture risk in old age is debated. In a cross-sectional controlled mixed model design, we compared dual X-ray absorptiometry-derived bone mineral density ( BMD) and bone size in 193 active and retired male elite soccer players and 280 controls, with duplicate measurements of the same individual done a mean 5 years apart. To evaluate lifetime fractures, we used a retrospective controlled study design in 397 retired male elite soccer players and 1368 controls. Differences in bone traits were evaluated by Student's t-test and fracture risk assessments by Poisson regression and Cox regression. More than 30 years after retirement from sports, the soccer players had a Z-score for total body BMD of 0.4 (0.1 to 0.6), leg BMD of 0.5 (0.2 to 0.8), and femoral neck area of 0.3 (0.0 to 0.5). The rate ratio for fracture after career end was 0.6 (0.4 to 0.9) and for any fragility fracture 0.4 (0.2 to 0.9). Exercise-associated bone trait benefits are found long term after retirement from sports together with a lower fracture risk. This indicates that physical activity in youth could reduce the burden of fragility fractures. [ABSTRACT FROM AUTHOR]

The present intervention was designed to investigate whether a 14-week period of regular recreational association football (F) or endurance running (R) has an effect on the risk of falls and bone fractures due to gains in muscle function and volumetric bone mineral density (vBMD). Fifty healthy untrained Danish premenopausal women were randomized into two training groups (F and R) that trained 1.8±0.3 (±SD) and 1.9±0.3 h/week, respectively, and these groups were compared with an inactive control group (C). Jumping and dynamic muscle strength were tested and tibial vBMD was measured using peripheral quantitative computed tomography. Total vBMD in left and right tibia increased by 2.6±2.3% and 2.1±1.8% ( P<0.005), respectively, in F and by 0.7±1.3% ( P=0.05) and 1.1±1.5% ( P<0.01), respectively, in R without any significant changes in C. Similar results were found for trabecular vBMD. In F, peak jump power increased by 3±6% ( P<0.05), and hamstring strength during fast (240°/s) and slow (30°/s) contractions increased by 11±25% and 9±21%, respectively, ( P<0.05) without any significant changes in R or C. In conclusion, 14 weeks of regular recreational football improved peak jump power, maximal hamstring strength and vBMD in the distal tibia, suggesting a decreased fracture risk due to stronger bones and a reduced risk of falling. [ABSTRACT FROM AUTHOR]

This non-randomized prospective controlled study evaluates a daily school-based exercise intervention program of 40 min/school day for 1 year in a population-based cohort of 81 boys aged 7–9 years. Controls were 57 age-matched boys assigned to the general school curriculum of 60 min/week. Bone mineral content (BMC; g) and areal bone mineral density (aBMD; g/cm2) were measured with dual X-ray absorptiometry (DXA) of the total body, the third lumbar vertebra (L3) and the femoral neck (FN). Bone width for L3 and FN was calculated from the lumbar spine and hip scan. No differences between the groups were found at baseline in age, anthropometrics or bone parameters. The mean annual gain in L3 BMC was 5.9 percentage points higher ( P<0.001), L3 aBMD a mean 2.1 percentage points higher ( P=0.01) and L3 width a mean 2.3 percentage points higher ( P=0.001) in the cases than in the controls. When all individuals were included in one cohort, the total duration of exercise including both school-based and spare-time training correlated with L3 BMC ( r=0.26, P=0.003), L3 aBMD ( r=0.18, P=0.04) and L3 width ( r=0.24, P=0.006). The study suggests that exercise in pre-pubertal boys influences the accrual of bone mineral and bone width and that a 1-year school-based exercise program confers skeletal benefits, at least in the lumbar spine. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the association between physical activity (PA) and skeletal growth in girls during adolescence. Design: A 5-year, observational, population-based study (Reykjavik, Iceland). Subjects: Seventy-eight Caucasian girls, mean age 13.4±1.0 (mean±SD) years at baseline. Methods: Bone mineral density (BMD, g/cm2) and bone width (cm) were measured in the forearm by single-photon absorptiometry at baseline and with dual-energy X-ray absorptiometry after 3 and 5 years, when lumbar spine, femoral neck (FN) and total body were also evaluated. Half of the physically active girls were compared with the other half of less active girls. Results: BMD in physically active girls was higher in the forearm at both baseline ( P=0.001) and after 5 years ( P=0.04) in comparison with less active girls. BMD was higher for the total body ( P=0.0001), spine L2–L4 ( P=0.02) and FN ( P=0.002) in the active girls at age 18. The accrual of forearm BMD and bone width from age 13 to 18 was no different when comparing the two groups. Conclusions: Pre-pubertal PA is associated with high BMD at age 13 and continued PA is associated with maintenance of high BMD until age 18. [ABSTRACT FROM AUTHOR]