Physical activity and cardiovascular risk factors in children
ABSTRACT A number of recent systematic reviews have resulted in changes in international recommendations for children's participation in physical activity (PA) for health. The World Health Authority (WHO) has recently released new recommendations. The WHO still recommends 60 min of moderate to vigorous physical activity (MVPA), but also emphasises that these minutes should be on top of everyday physical activities. Everyday physical activities total around 30 min of MVPA in the quintile of the least active children, which means that the new recommendations constitute more activity in total compared with earlier recommendations.
To summarise evidence justifying new PA recommendation for cardiovascular health in children.
The results of recent systematic reviews are discussed and supplemented with relevant literature not included in these reviews. PubMed was searched for the years 2006-2011 for additional topics not sufficiently covered by the reviews.
PA was associated with lower blood pressure and a healthier lipid blood profile in children. The association was stronger when a composite risk factor score was analysed, and the associations between physical fitness and cardiovascular disease (CVD) risk factors were even stronger. Muscle strength and endurance exercise each had an effect on blood lipids and insulin sensitivity even if the effect was smaller for muscle strength than for aerobic exercise. New evidence suggests possible effects of PA on C-reactive protein.
There is accumulating evidence that PA can have beneficial effects on the risk factors of CVD in children. Public health policy to promote PA in children, especially the most sedentary children, may be a key element to prevent the onset of CVD later in the children's lives.
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ABSTRACT: To investigate whether light exposure was associated with objectively measured physical activity (PA) and sedentary behaviour in young people. Participants (n = 229, 46.7% female) were young people (mean 8.8 years [SD ± 2.2]) from the borough of Camden, UK. Daily sedentary time, moderate and vigorous PA (MVPA) and light exposure were measured using a tri-axial accelerometer with an ambient light sensor during the summer. Multiple linear regression models examined associations between average daily light exposure, sedentary time and time in MVPA. Models were repeated investigating weekdays and weekend days separately. Analyses were adjusted for pre-specified covariables, including age, sex, device wear time, ethnic group, school and body fat. There were significant associations between average daily light exposure and time sedentary (β coefficient = -11.2, 95% CI, -19.0 to -3.4) and in MVPA (β coefficient = 3.5, 95% CI, 1.2 to 5.9). Light exposure was significantly associated with weekend sedentary time (β coefficient = -10.0, 95% CI, -17.6, -2.4), weekend MVPA (β coefficient = 3.7, 95% CI, 1.7, 5.7), weekday sedentary time (β coefficient = -15.0, 95% CI, -22.7 to -7.2), but not weekday MVPA (β coefficient = 2.0, 95% CI, -0.5 to 4.5). Average daily light exposure is positively associated with time in MVPA and negatively associated with sedentary time. Increasing daylight exposure may be a useful intervention strategy for promoting physical activity.International journal of environmental research and public health 03/2015; 12(3). DOI:10.3390/ijerph120302941 · 1.61 Impact Factor
Article: Authors' reply to Metcalf and Wilkin[Show abstract] [Hide abstract]
ABSTRACT: Childhood obesity is complex.1 We acknowledged that to change behaviour and prevent childhood obesity is difficult when acting in only one sector—in this case, schools—especially in a socially disadvantaged population.2 However, this difficulty should not prevent all sectors from playing their part. In addition, a shift of the population median by a few points on the centile scale into the favourable direction, as documented in our intervention group for body fat and fitness, would be expected to have a considerable impact on public health.3Our observed decrease in body fat may not seem large, but, given the low baseline values of body fat in this healthy young population (overweight prevalence 12%), it amounts to a non-negligible 5% benefit in percentage body fat and 10% benefit in the more direct measure, the sum of four skinfold thicknesses.We observed no improvement in measured physical activity over one week (and we gave possible reasons why), in contrast to our other recent school based intervention.4 Reported physical activity did, however, improve: parents in the intervention group observed that their children were more active. Physical activity is a difficult behaviour to measure. Aerobic fitness is more stable and improved with an intervention effect of around 11% of mean baseline values.Aerobic fitness has decreased around 10% in the past three decades,5 so this effect is of substantial public health relevance. Aerobic fitness is related to a decrease in clustered cardiovascular disease risk factors in children4 6 and to a lower total and cardiovascular mortality in adults.7NotesCite this as: BMJ 2012;344:e717BMJ Clinical Research 01/2012; 344(jan31 1):e717-e717. DOI:10.1136/bmj.e717 · 14.09 Impact Factor
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ABSTRACT: The adolescent period is associated with changes in eating and activity behaviors in girls. Less reliance on parental provision and choice of food, coupled with a decrease in participation in physical activity and sport, can create an energy imbalance, predisposing to weight gain. Physiological alterations to body composition, reduction in insulin sensitivity, and psychological adjustments may further amplify the risk of becoming overweight and maintaining an unhealthy level of body fat into childbearing years. During pregnancy excess body fat is a risk factor for poor pregnancy outcomes and may predispose an infant to a lifelong heightened risk of being overweight and developing chronic disease. Interventions aimed at preventing the accumulation of body fat in adolescent girls and young women may have far reaching impact and be critically important in reducing intergenerational weight gain. Lifestyle interventions in adolescence have the potential to modify adult obesity risk by switching at-risk individuals from a high to lower obesity risk trajectory. This paper discusses multiple approaches to assist at-risk individuals reduce obesity risk. A key focus is placed on engagement in food preparation and choice, and opportunities for physical activity and sport. Support, education, and opportunity at home and at school, are often associated with the success of lifestyle interventions, and may enable adolescents to make positive choices, and engage in health promoting behaviors during adolescence and childbearing years.International journal of environmental research and public health 02/2015; 12(2):2306-2329. DOI:10.3390/ijerph120202306 · 1.61 Impact Factor