Maximum oxygen uptake and objectively measured physical activity in Danish children 6–7 years of age: the Copenhagen School Child Intervention Study

Institute for Exercise and Sport sciences, University of Copenhagen, Denmark.
British Journal of Sports Medicine (Impact Factor: 5.03). 10/2005; 39(10):725-30. DOI: 10.1136/bjsm.2004.015230
Source: PubMed


To provide normative data on maximum oxygen uptake (Vo(2)max) and physical activity in children 6-7 years of age and analyse the association between these variables.
Vo(2)max was measured in 366 boys (mean (SD) 6.8 (0.4) years of age) and 332 girls (6.7 (0.4) years of age) from preschool classes in two suburban communities in Copenhagen, during a progressive treadmill exercise. Habitual physical activity was measured with accelerometers.
Boys had higher Vo(2)max both in absolute values (1.19 (0.18) v 1.06 (0.16) litres/min (+11%), p<0.001) and relative to body weight (48.5 (6.0) v 44.8 (5.6) ml/kg/min (+8%); p<0.001) than girls. The difference in Vo(2)max between boys and girls decreased to +2% when expressed relative to lean body mass (LBM). Absolute Vo(2)max was related to LBM, body mass, and stature (all p<0.001). Boys were more physically active than girls (mean counts +9.4%, p<0.001), and even when boys and girls with the same Vo(2)max were compared, boys were more active. The difference in physical activity between the sexes was higher when sustained activity of higher intensity was compared.
Vo(2)max is higher in boys than girls (+11%), even when related to body mass (+8%) and LBM (+2%). Most of the difference in Vo(2)max relative to body mass was explained by the larger percentage body fat in girls. When boys and girls with the same Vo(2)max were compared, boys engaged in more minutes of exercise of at least moderate intensity.

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    • "By using a qualitative approach and gender concepts as theoretical framework, this study contributes to the growing literature on gender differences in children's PA levels during recess (Currie et al., 2012; Dencker and Andersen, 2008; Eiberg et al., 2005; Hallal et al., 2012; Nielsen et al., 2011; Riddoch et al., 2004; Sallis et al., 2000) by exploring children's own experiences of and justification for gendered play by drawing on observations and go-along interviews. In order to improve understanding of the influences on girls' as well as boys' PA level, the aim of the study is to explore how the construction of gendered activity patterns and social positions in the schoolyard lead to gender reinforcing practices in selforganized play during recess. "
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    • "In spite of this, there are only a few population studies on normative data concerning maximal exercise test parameters in healthy children from different age groups (Eiberg et al. 2005; Dencker et al. 2008; Ten Harkel et al. 2011; Lintu et al. 2014). We, therefore, aimed to provide comprehensive data on and reference values for cardiorespiratory fitness, respiratory function and hemodynamic responses during and after maximal cycle ergometer exercise test in girls and boys 9–11 years of age. "
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    • "Consistent with our observations, Longin et al. (2009) who used 5-min ECG recordings and Fukuba et al. (2009) who used 3-min ECG recordings found no sex differences in HRV parameters. A possible explanation for the sex differences in some HRV parameters obtained from long-term ECG recordings is that habitual physical activity and some other factors that have an effect on HRV parameters may be different between sexes during uncontrolled long-term recordings (Bernardi et al., 1996; Eiberg et al., 2005). HRV parameters change as a function of age, because autonomic nervous system maturates and average heart rate decreases during growth (Finley & Nugent, 1995; Goto et al., 1997; Massin & von Bernuth, 1997). "
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