Weight Status Is Related to Health-Related Physical Fitness and Physical Activity but Not to Sedentary Behaviour in Children.

Purpose: The aim of this research was to describe, examine, and compare the level of physical fitness, physical activity, and sedentary behaviour in pupils aged 6-13 in the Region of Murcia, Spain, in accordance with weight status.
Methods: A total of 370 children (166 girls and 204 boys) aged 6-13 (M = 8.7; DT = 1.8) from the Region of Murcia participated in this descriptive and cross-sectional study. Some anthropometric parameters such as body mass index, waist circumference, as well as skinfold measurements were determined. ALPHA-FIT Test Battery was used to evaluate physical fitness. Krece Plus Short Test was used to measure physical activity level and sedentary behaviour.
Results: 52.4% of the children presented excess weight (according to the World Health Organization growth references). Regarding boys, statistically significant differences were found for cardiorespiratory fitness (p < 0.001), relative handgrip strength (p < 0.001), lower muscular strength (p < 0.001), speed-agility (p < 0.001), as well as sport activities hours (p = 0.001) among the three weight status groups (normal weight, overweight, and obesity). As for girls, statistically significant differences were found for cardiorespiratory fitness (p = 0.004), relative handgrip strength (p < 0.001), lower muscular strength (p < 0.001), sport activities hours (p = 0.005), as well as physical activity level (assessed by Krece Plus Test) (p = 0.017). A negative statistically significant correlation was found between body mass index and cardiorespiratory fitness (rho = -0.389), lower muscular strength, (rho = -0.340), and relative handgrip strength (rho = -0.547). At the same time, a positive statistically significant relationship between body mass index and the time spent in speed-agility (rho = 0.263) was shown. Regarding waist circumference and body fat percentage, similar relationships were identified. Moreover, a greater probability of having higher cardiorespiratory fitness (OR = 1.58; CI95% = 1.38-1.82), relative handgrip strength (OR = 1.25; CI95% = 1.19-1.31), more hours of sport activities (OR = 1.40; CI95% = 1.19-1.66), and physical activity level (assessed by Krece Plus Test) (OR = 1.23; CI95% = 1.07-1.42) was noted in the normal weight group. Conclusions: Children that presented normal weight achieved higher results for health-related physical fitness and physical activity than those with excess weight; this was, however, not found to be the case for sedentary behaviour. The authors emphasise the need for changes in public policies and school-based intervention programmes to develop higher levels of both PF and PA in overweight and obese children.