on behalf of the IDEFICS consortium BACKGROUND/OBJECTIVES: A low fitness status during childhood and adolescence is associated with important health-related outcomes, such as increased future risk for obesity and cardiovascular diseases, impaired skeletal health, reduced quality of life and poor mental health. Fitness reference values for adolescents from different countries have been published, but there is a scarcity of reference values for pre-pubertal children in Europe, using harmonised measures of fitness in the literature. The IDEFICS study offers a good opportunity to establish normative values of a large set of fitness components from eight European countries using common and well-standardised methods in a large sample of children. Therefore, the aim of this study is to report sex-and age-specific fitness reference standards in European children. SUBJECTS/METHODS: Children (10 302) aged 6-10.9 years (50.7% girls) were examined. The test battery included: the flamingo balance test, back-saver sit-and-reach test (flexibility), handgrip strength test, standing long jump test (lower-limb explosive strength) and 40-m sprint test (speed). Moreover, cardiorespiratory fitness was assessed by a 20-m shuttle run test. Percentile curves for the 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentiles were calculated using the General Additive Model for Location Scale and Shape (GAMLSS). RESULTS: Our results show that boys performed better than girls in speed, lower-and upper-limb strength and cardiorespiratory fitness, and girls performed better in balance and flexibility. Older children performed better than younger children, except for cardiorespiratory fitness in boys and flexibility in girls. CONCLUSIONS: Our results provide for the first time sex-and age-specific physical fitness reference standards in European children aged 6-10.9 years.

This study investigated the effects of a 10-month high-intensity interval-type neuromuscular training program on musculoskeletal fitness in overweight and obese women. Forty-nine inactive females (36.4±4.4 yrs) were randomly assigned to either a control (N=21), a training (N=14, 10 months) or a training-detraining group (N=14, 5 months training followed by 5 months detraining). Training used progressive loaded fundamental movement patterns with prescribed work-to-rest intervals (1:2, 1:1, 2:1) in a circuit fashion (2-3 rounds). Muscular strength and endurance, flexibility, passive range of motion (PRoM), static balance, functional movement screen (FMS) and bone mass density (BMD) and content (BMC) were measured at pre-, mid-, and post-intervention. Ten months of training induced greater changes than the controls in (i) BMD (+1.9%, p<0.001) and BMC (+1.5%, p=0.023) ii) muscular strength (25%-53%, p=0.001-0.005); iii) muscular endurance (103%-195%, p<0.001); and iv) mobility

Background and aims:The association between bone turnover markers and bone mass in adolescence is not clear. We aimed to evaluate the associations between bone turnover markers and bone mineral content (BMC), density (BMD) and area (BMA). Subjects: A total of 56 adolescents (25 boys, 12.5 -17.5 years) participated in the study. Methods: Bone mass and physical activity (PA) were measured using dual energy X-ray absorptiometry and accelerometers. Osteocalcin and amino-terminal propeptide of type I procollagen (PINP), as markers of bone formation, and β -isomer of the C-terminal telopeptide of type I collagen, as marker of bone resorption were also measured. Sexual maturation, weight, height and average PA were considered as confounders. Results: Positive correlations (Pearson) were observed among the three bone turnover markers (r = 0.7 -0.9). Stepwise multiple linear regression analyses showed that PINP was strong and negatively associated with BMC, BMD and BMA in girls, explaining 24.9 % of the variance in BMC, 25.6 % in BMD and 16.3 % in BMA. Conclusion: PINP is a strong predictor of bone related variables in pubertal girls.

Summary Background The relationship of obesity with grey and white matter volumes has been examined in several studies, and the results are decidedly mixed. Objective To investigate the associations of body mass index (BMI), fat mass index (FMI) and lean mass index (LMI) with total and regional grey and white matter volumes. Methods This is a cross‐sectional study involving 100 children (60% boys) with overweight/obesity. T1‐weighted images were acquired using magnetic resonance imaging. Dual energy X‐ray absorptiometry was used to measure body composition. Separate hierarchical regression analyses were performed between predictor variables (BMI, FMI and LMI) and the total brain volumes including sex, years from peak height velocity and parental education as covariates. In addition, FMI was added as a covariate when LMI was the predictor and vice versa. Statistical analyses of imaging data were performed using three whole‐brain voxel‐wise multiple regression models and adjusted by the same covariates. Results LMI was positively associated with white matter in numerous regions and to a lower extent, with grey matter regions. Further, the relationship between LMI, and grey and white matter regions was independent of FMI levels. Conclusions LMI seems to be a positive predictor of regional white matter volumes in children with overweight/obesity.