A 3-year physical activity intervention program increases the gain in bone mineral and bone width in prepubertal girls but not boys: the prospective copenhagen school child interventions study (CoSCIS).
The aim of this study was to evaluate the effect of increasing the amount of time spent in physical education classes on bone mineral accrual and gain in bone size in prepubertal Danish children. A total of 135 boys and 108 girls, aged 6-8 years, were included in a school-based curriculum intervention program where the usual time spent in physical education classes was doubled to four classes (180 min) per week. The control group comprised age-matched children (62 boys and 76 girls) recruited from a separate community who completed the usual Danish school curriculum of physical activity (90 min/week). Dual-energy X-ray absorptiometry was used to evaluate bone mineral content (BMC; g), bone mineral density (g/cm(2)), and bone width at the calcaneus and distal forearm before and after 3 years of intervention. Anthropometrics and Tanner stages were evaluated on the same occasions. General physical activity was measured with an accelerometer worn for 4 days. In girls, the intervention group had a 12.5% increase (P = 0.04) in distal forearm BMC and a 13.2% increase (P = 0.005) in distal forearm scanned area compared with girls in the control group. No differences were found between the intervention and control groups in boys. Increasing the frequency of physical education classes for prepubertal children is associated with a higher accrual of bone mineral and higher gain in bone size after 3 years in girls but not in boys.
The aim of this study was to investigate changes over six years in physical activity and sedentary behavior assessed with accelerometry in a representative sample of Swedish adults.
A longitudinal study over six years.
The cohort consisted of 1172 participants (46% males) in 2002 and 511 participants (46% males) in 2008, of which 478 (45% males) had valid data on both occasions. Mean (SD) age at baseline was 45 (15) years. To analyze changes over time, a mixed linear model for average intensity physical activity (counts/min) and time in sedentary behavior and light- and moderate- or higher-intensity physical activity was conducted, stratified for sex and age, and adjusted for BMI, education, self-rated health and ? wear time.
Over a six year period no significant changes were seen in the total cohort for average intensity and time in moderate- or higher intensity physical activity. A significant decrease in average intensity physical activity was found for men (p=0.006) and those aged 60+ years at baseline (p
Obesity- and virus-mediated insulin resistance (IR) are associated with adverse hepatic and metabolic outcomes in chronic hepatitis C (CHC). This study evaluates the tolerability and effects of a dietary and physical activity (PA) intervention in obese patients with insulin-resistant CHC.
Obese patients (body mass index, BMI =30 kg/m(2) ) with CHC were recruited prospectively. Non-diabetic patients with IR (homeostasis model assessment of IR, HOMA-IR >2.0) proceeded to a 24-week lifestyle intervention comprising pedometer monitored increase in PA (=10 000 steps/day) and an individualised dietary plan.
Ten non-cirrhotic and six cirrhotic patients [age 52 ± 8.5 years, BMI 35.9 (31.46-38.21)kg/m(2) ] were recruited, of whom all 16 (100%) completed the 24-week protocol. Increase in PA from 6853 (2440-9533) to 10 697 (7959-13566) steps/day (P = 0.001) and reduction in caloric intake from 2263 (1805.4-2697.0) to 1281 (1099.5-1856.3) kcal/day (equivalent to reduction of median 33% (25.3-49.8%), P
This study investigated the validity of the Actiheart device for estimating free-living physical activity energy expenditure (PAEE) in adolescents.
Total energy expenditure (TEE) was measured in eighteen Canadian adolescents, aged 15-18 years, by DLW. Physical activity energy expenditure was calculated as 0.9 X TEE minus resting energy expenditure, assuming 10% for the thermic effect of feeding. Participants wore the chest mounted Actiheart device which records simultaneously minute-by-minute acceleration (ACC) and heart rate (HR). Using both children and adult branched equation modeling, derived from laboratory-based activity, PAEE was estimated from the ACC and HR data. Linear regression analyses examined the association between PAEE derived from the Actiheart and DLW method where DLW PAEE served as the dependent variable. Measurement of agreement between the two methods was analyzed using the Bland-Altman procedure.
A nonsignificant association was found between the children derived Actiheart and DLW PAEE values (R = .23, R(2) = .05, p = .36); whereas a significant association was found between the adult derived Actiheart and DLW PAEE values (R = .53, R(2) = .29, p
Middle-aged women with active commuting had significantly lower risk for wrist fracture than women commuting by car/bus.
Our purpose was to investigate whether a physically active lifestyle in middle-aged women was associated with a reduced risk of later sustaining a low-trauma wrist fracture.
The Umeå Fracture and Osteoporosis (UFO) study is a population-based nested case-control study investigating associations between lifestyle and fragility fractures. From a cohort of ~35,000 subjects, we identified 376 female wrist fracture cases who had reported data regarding their commuting habits, occupational, and leisure physical activity, before they sustained their fracture. Each fracture case was compared with at least one control drawn from the same cohort and matched for age and week of reporting data, yielding a total of 778 subjects. Mean age at baseline was 54.3?±?5.8 years, and mean age at fracture was 60.3?±?5.8 years.
Conditional logistic regression analysis with adjustments for height, body mass index, smoking, and menopausal status showed that subjects with active commuting (especially walking) were at significantly lower risk of sustaining a wrist fracture (OR 0.48; 95 % CI 0.27-0.88) compared with those who commuted by car or bus. Leisure time activities such as dancing and snow shoveling were also associated with a lower fracture risk, whereas occupational activity, training, and leisure walking or cycling were unrelated to fracture risk.
This study suggests that active commuting is associated with a lower wrist fracture risk, in middle-aged women.
The purpose was to describe the patterns of commuting to school in young people and to examine its associations with physical activity (PA) and cardiorespiratory fitness.
The sample comprised 2271 Estonian and Swedish children and adolescents (1218 females) aged 9-10 years and 15-16 years. Data were collected in 1998/99. Mode of commuting to and from school was assessed by questionnaire. Time spent (min/day) in PA and average PA (counts/min) was measured by accelerometry. Cardiorespiratory fitness was assessed by means of a maximal cycle ergometer test.
Sixty-one percent of the participants reported active commuting to school (ACS). Estonian youth showed lower levels of ACS than Swedish (odds ratio, 0.64; 95% confidence interval, 0.53-0.76) and girls reported lower levels than boys (0.74; 0.62-0.88). ACS boys showed higher PA levels than non-ACS boys for moderate, vigorous, MVPA, and average PA levels (all p = 0.01). Participants who cycled to school had higher cardiorespiratory fitness than walkers or passive travellers (p
STUDY DESIGN: Prospective cohort study of twins. OBJECTIVES: To investigate associations between physical activity, physical function, and incident low back pain (LBP) in an elderly population. SUMMARY OF BACKGROUND DATA: The relationship between an active lifestyle and LBP in seniors is unknown. METHODS: Participants in the population-based Longitudinal Study of Aging Danish Twins free from LBP at baseline (no LBP during the past month) were included, and interview data on physical activity, overall physical function, and LBP at baseline and follow-up were obtained. Associations between levels of physical activity and LBP were estimated using logistic regression for the entire cohort, and using a matched case-control design for twin pairs discordant for physical activity. Absolute risk and relative risks for incident LBP in relation to physical activity were calculated for participants with higher or lower than average physical function at baseline. Absolute risk for LBP was also calculated for participants based on whether they remained active or inactive between baseline and follow-up or changed activity level. RESULTS: A total of 1387 persons aged 70-100 at baseline were included in the analyses, including 86 twin pairs discordant for physical activity at baseline. In the total sample, 83% were engaged in light physical activity, and 42% of men and 35% of women were engaged in strenuous physical activity at least weekly. Being engaged in strenuous physical activity at baseline was strongly protective in relation to both having had any LBP (odds ratio 0.21, 95% confidence interval 0.12-0.37 for intra-pair analysis) and having had LBP lasting more than 30 days altogether during the past year at follow-up (odds ratio 0.08, 95% confidence interval 0.03-0.18 for intra-pair analysis). Statistically significant dose-response associations between increasing frequency of strenuous physical activity and magnitude of this protective effect were found. Participants with poor initial physical function experienced the strongest protective effect of strenuous physical activity. Finally, LBP does not appear to be an important factor affecting whether participants remained engaged in strenuous physical activity at baseline and follow-up or vice versa. CONCLUSIONS: Strenuous physical activity at least once a week is protective for incident LBP in seniors.
This study examines how active transportation could help increase the daily physical activity volume of school-aged children.
Using data from the 2003 Origin-Destination Survey carried out among 5% of the 3.5 million residents of the Greater Montreal Area, we determined the proportion of short motorized trips made daily by children 5-14 years old (16 837 children sampled) and estimated the number of steps these trips would account for if they were travelled by foot, taking into account variables such as age, sex and height of children. Modal choice and trip purpose were also examined.
In 2003, 31.2% of the daily trips made by children aged 5-14 years in the Greater Montreal Area were 1 km or less (0.6 mile). Of these, 33.0% were motorized trips. Overall, 13.1% of the children in the area had 'steps in reserve', an average of 2238 steps per child per day. If they were performed, these steps would account for 16.6% of the daily recommended volume of physical activity for children.
Replacing short motorized trips with walking could increase the physical activity level of children and contribute to meet the recommended guidelines, as long as these walking trips add to their daily physical activity volume. It could also reduce their dependence towards adults for moving around.
PURPOSE: Active travel to school provides an opportunity for daily physical activity. Previous studies have shown that walking and cycling to school are associated with higher physical activity levels. The purpose of this study was to investigate whether the way that children and adolescents travel to school is associated with level of cardiovascular fitness. METHODS: Participants were recruited via a proportional, two-stage cluster sample of schools (N = 25) in the region of Odense, Denmark as part of the European Youth Heart Study (EYHS). Nine hundred nineteen participants (529 children, age 9.7 +/- 0.5 yr; 390 adolescents, age 15.5 +/- 0.4 yr) completed a maximal cycle ergometer test to assess cardiorespiratory fitness (Wmax x kg(-1)). Mode of travel to school was investigated by questionnaire. Physical activity was measured in 531 participants using an accelerometer. Regression analyses with robust standard errors and adjustment for confounders (gender, age, body composition (skinfolds), pubertal status, and physical activity) and the cluster sampling procedure were used to compare fitness levels for different travel modes. Multinomial logistic regression was applied to assess the odds for belonging to quartiles of fitness. RESULTS: Children and adolescents who cycled to school were significantly more fit than those who walked or traveled by motorized transport and were nearly five times as likely (OR 4.8; 95% CI 2.8-8.4) to be in the top quartile of fitness. CONCLUSION: Cycling to school may contribute to higher cardiovascular fitness in young people.
The activity budgets and daily activity rhythms of Varecia rubra were examined over an annual cycle according to season and reproductive stage. Given the relatively high reproductive costs and patchy food resources of this species, I predicted that V. rubra would 1) travel less and feed more during seasonal resource scarcity in an attempt to maintain energy balance, and 2) show sex differences in activity budgets due to differing reproductive investment. Contrary to the first prediction, V. rubra does not increase feeding time during seasonal food scarcity; rather, females feed for a consistent amount of time in every season, whereas males feed most during the resource-rich, hot dry season. The results are consistent with other predictions: V. rubra travels less in the resource-scarce cold rainy season, and there are some pronounced sex differences, with females feeding more and resting less than males in every season and in every reproductive stage except gestation. However, there are also some provocative similarities between the sexes when activity budgets are examined by reproductive stage. During gestation, female and male activity budgets do not differ and appear geared toward energy accumulation: both sexes feed and rest extensively and travel least during this stage. During lactation, activity budgets are geared toward high energy expenditure: both sexes travel most and in equal measure, and rest least, although it remains the case that females feed more and rest less than males. These similarities between female and male activity budgets appear related to cooperative infant care. The high energetic costs of reproduction in V. rubra females may require that they allot more time to feeding year round, and that their overall activity budget be more directly responsive to seasonal climate change, seasonal food distribution, and reproductive schedules.