The aim of this study was to provide objective data on the cardiopulmonary fitness and physical activity patterns of Northern Irish postprimary schoolchildren. Forty-five children (23 boys, 22 girls), ages 11-16 years, took part in this study. Each child performed a laboratory test of peak aerobic power (PVO2) and had his/her heart rate monitored for up to 4 school days. The mean values of PVO2 in both boys and girls were in keeping with previous literature. No significant difference was observed between boys and girls in terms of total activity (>50% PVO2), but boys engaged in significantly more vigorous activity (>70% PVO2 than girls did (p<0.05). Younger boys engaged in significantly more vigorous activity than both older boys (p<0.01) and younger girls (p<0.05). A significant negative correlation was found between age and total activity for boys (r= −0.476, p<0.05), but not for girls (r= -0.173, n.s.). The surprisingly low levels of physical activity on the part of older children of both sexes are a cause for concern.
Chris Riddoch, Craig Mahoney, Niamh Murphy, Colin Boreham and Gordon Cran
Alex Griffiths, Calum Mattocks, Andy Robert Ness, Kate Tilling, Chris Riddoch and Sam Leary
A study deriving a threshold for moderate- to vigorous-intensity physical activity (MVPA) in terms of accelerometer counts in 12-year-old children was repeated with a subset of the same children at 16 years.
Fifteen girls and thirty boys took part in 6 activities (lying, sitting, slow walking, walking, hopscotch and jogging) while wearing an Actigraph 7164 accelerometer and a Cosmed K4b2 portable metabolic unit. Random intercepts modeling was used to estimate cut points for MVPA (defined as 4 METs).
Using a single model, the sex-specific thresholds derived for MVPA at 16 years were some way below the 3600 counts/minute used for both sexes at age 12, particularly for girls. However graphical examination suggested that a single model might be inadequate to describe both higher- and lower-intensity activities. Models using only lower-intensity activities close to the 4 METs threshold supported retention of the 3600 counts/minute cut point for both sexes.
When restricting to lower-intensity activities only, these data do not provide sufficient evidence to change the previously established cut point of 3600 counts/minute to represent MVPA. However, further data and more sophisticated modeling techniques are required to confirm this decision.
Niels Wedderkopp, Karsten Froberg, Henrik Steen Hansen, Chris Riddoch and Lars Bo Andersen
The aim of this study was to assess the association between physical fitness and clustering of cardiovascular disease (CVD) risk factors in boys and girls aged 9 years (children) and 15 years (adolescents). Subjects were 1020 randomly selected children and adolescents. Cardiorespiratory fitness was assessed by a maximal cycle ergometer test. A subject was defined as having a risk factor if he/she belonged to the upper quartile of risk within age and gender group for that risk factor. Clustering was analysed in relation to being at risk in a) three or more and b) four or more of five possible risk factors (TC:HDL ratio, insulin:glucose ratio, triglyceride, systolic BP and sum of four skinfolds. Physical fitness was weakly related to single CVD risk factors except sum of skinfolds where the relationship was strong. Low fitness increased the risk of having three or more CVD risk factors with odds ratios (OR) using the upper quartile of fitness as reference of 1.9 (95% CI: 0.8–4.1), 3.0 (95% CI: 1.4–6.3) and 11.4 (95% CI: 5.7–22.9), respectively. Using the criterion of four or more risk factors, an OR of 24.1 (95% CI 5.7–101.1) was found in the low fit group.
Harriet Koorts, Calum Mattocks, Andy R. Ness, Kevin Deere, Steven N. Blair, Russell R. Pate and Chris Riddoch
Little is known about how the type and context of physical activity behaviors varies among adolescents with differing activity levels. The aim of this study was to assess differences in the type and context of physical activity behaviors in adolescents by level of objectively measured physical activity.
Cross-sectional analysis of 2728 adolescents (1299 males, 1429 females) participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). The mean (SD) age was 13.8 (+0.1) years. Physical activity was measured using an Actigraph over 7 days. Adolescents were categorized into tertiles of activity (less, moderately, highly active) using counts/min and min/d of moderate-to-vigorous activity (MVPA). Activity type was reported using the Previous Day Physical Activity Recall (PDPAR). Differences in the type and context of activity by activity level were analyzed using Chi squared.
Highly active boys reported more job, outside, and sports activities on school days (P < .05), and more sports activities on nonschool days (P < .05). Highly active girls reported more outside activities on school days (P < .05).
Identifying the type and context of physical activity behaviors associated with more active adolescents, can help inform policy and physical activity interventions aimed at increasing activity levels in adolescents.
Calum Mattocks, Andy Ness, Sam Leary, Kate Tilling, Steven N. Blair, Julian Shield, Kevin Deere, Joanne Saunders, Joanne Kirkby, George Davey Smith, Jonathan Wells, Nicholas Wareham, John Reilly and Chris Riddoch
Objective methods can improve accuracy of physical activity measurement in field studies but uncertainties remain about their use.
Children age 11 years from the Avon Longitudinal Study of Parents and Children (ALSPAC), were asked to wear a uni-axial accelerometer (MTI Actigraph) for 7 days.
Of 7159 children who attended for assessment, 5595 (78%) provided valid measures. The reliability coefficient for 3 days of recording was .7 and the power to detect a difference of 0.07 SDs (P ≤ .05) was > 90%. Measures tended to be higher on the first day of recording (17 counts/min; 95% CI, 10–24) and if children wore the monitor for fewer days, but these differences were small. The children who provided valid measures of activity were different from those who did not, but the differences were modest.
Objective measures of physical activity can be incorporated into large longitudinal studies of children.
Chris Riddoch, Dawn Edwards, Angie Page, Karsten Froberg, Sigmund A. Anderssen, Niels Wedderkopp, Søren Brage, Ashley R. Cooper, Luis B. Sardinha, Maarike Harro, Lena Klasson-Heggebø, Willem van Mechelen, Colin Boreham, Ulf Ekelund, Lars Bo Andersen and The European Youth Heart Study Team
The aim of the European Youth Heart Study (EYHS) is to establish the nature, strength, and interactions between personal, environmental, and lifestyle influences on cardiovascular disease (CVD) risk factors in European children.
The EYHS is an international study measuring CVD risk factors, and their associated influences, in children. Relationships between these independent factors and risk of disease will inform the design of CVD interventions in children. A minimum of 1000 boys and girls ages 9 and 15 y were recruited from four European countries—Denmark, Estonia, Norway, and Portugal. Variables measured included physical, biochemical, lifestyle, psychosocial, and sociodemographic data.
Of the 5664 children invited to participate, 4169 (74%) accepted. Response rates for most individual tests were moderate to high. All test protocols were well received by the children.
EYHS protocols are valid, reliable, acceptable to children, and feasible for use in large, field-based studies.
Jacqueline Kerr, James F. Sallis, Neville Owen, Ilse De Bourdeaudhuij, Ester Cerin, Takemi Sugiyama, Rodrigo Reis, Olga Sarmiento, Karel Frömel, Josef Mitáš, Jens Troelsen, Lars Breum Christiansen, Duncan Macfarlane, Deborah Salvo, Grant Schofield, Hannah Badland, Francisco Guillen-Grima, Ines Aguinaga-Ontoso, Rachel Davey, Adrian Bauman, Brian Saelens, Chris Riddoch, Barbara Ainsworth, Michael Pratt, Tom Schmidt, Lawrence Frank, Marc Adams, Terry Conway, Kelli Cain, Delfien Van Dyck and Nicole Bracy
National and international strategies to increase physical activity emphasize environmental and policy changes that can have widespread and long-lasting impact. Evidence from multiple countries using comparable methods is required to strengthen the evidence base for such initiatives. Because some environment and policy changes could have generalizable effects and others may depend on each country’s context, only international studies using comparable methods can identify the relevant differences.
Currently 12 countries are participating in the International Physical Activity and the Environment Network (IPEN) study. The IPEN Adult study design involves recruiting adult participants from neighborhoods with wide variations in environmental walkability attributes and socioeconomic status (SES).
Eleven of twelve countries are providing accelerometer data and 11 are providing GIS data. Current projections indicate that 14,119 participants will provide survey data on built environments and physical activity and 7145 are likely to provide objective data on both the independent and dependent variables. Though studies are highly comparable, some adaptations are required based on the local context.
This study was designed to inform evidence-based international and country-specific physical activity policies and interventions to help prevent obesity and other chronic diseases that are high in developed countries and growing rapidly in developing countries.