The health, fitness and other advantages of youth sports participation are well recognised. However, there are considerable challenges for all stakeholders involvedespecially youth athletes-in trying to maintain inclusive, sustainable and enjoyable participation and success for all levels of individual athletic achievement. In an effort to advance a more unified, evidence-informed approach to youth athlete development, the IOC critically evaluated the current state of science and practice of youth athlete development and presented recommendations for developing healthy, resilient and capable youth athletes, while providing opportunities for all levels of sport participation and success. The IOC further challenges all youth and other sport governing bodies to embrace and implement these recommended guiding principles.

Dette er siste tekst-versjon av artikkelen, og den kan inneholde små forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på link.springer.com: http://dx.doi.org/10.2165/11597140-000000000-00000 This is the final text version of the article, and it may contain minor differences from the journal's pdf version. The original publication is available at link.springer.com: http://dx.doi.org/10.2165/11597140-000000000-00000 . Figure 3. Semi-automatic image evaluation: The edge detection algorithm for subcutaneous adipose tissue (SAT) thickness determination enables selecting areas of interest, distances (d US ) measurement series, color-coding of distance values, and statistical evaluations [48] . In this example of a SAT-layer above the triceps muscle, with the transducer held parallel to the humerus, 119 d US values ranging from 2.3 mm to 4.3 mm were automatically detected by the algorithm; the median was 3.4 mm (c = 1470 m/s). Layers and interfaces: A: gel, B: gel-epidermis, C: dermis, D: dermis-SAT, E: SAT, F: SAT-fascia of muscle, G: muscle. [77] . Abbreviations: mid dist = middle distance track runners; long dist = long distance runners; Scot long dist = Scottish long distance runners; SASI mid dist = South Australian Sports Institute middle distance track runners; SASI sprint = sprint runners; SASI jump = jumpers. Figure 6. Selected skinfold ratios in extremely lean male and female endurance athletes, and mean values from 106 male and 33 female athletes [80] . 4 ABSTRACTQuantifying human body composition has played an important role in monitoring all athlete performance and training regimens, but especially so in gravitational, weight class and aesthetic sports wherein the tissue composition of the body profoundly affects performance or adjudication. Over the past century, a myriad of techniques and equations have been proposed, but all have some inherent problems, whether in measurement methodology or in the assumptions they make. To date, there is no universally applicable criterion or "gold standard" methodology for body composition assessment.Having considered issues of accuracy, repeatability and utility, the multi-component model might be employed as a performance or selection criterion, provided the selected model accounts for variability in the density of FFM in its computation. However, when profiling change in interventions, single methods whose raw data are surrogates for body composition (with the notable exception of the BMI) remain useful.

Borgen, J. (2014). The LEAF questionnaire: a screening tool for the identification of female athletes at risk for the female athlete triad.

The purposes of this study were to examine the percentage of female elite athletes and controls with disordered eating (DE) behavior and clinical eating disorders (EDs), to investigate what characterize the athletes with EDs, and to evaluate whether a proposed method of screening for EDs in elite athletes does not falsely classify sport‐specific behaviors as indicators of EDs. All athletes representing the national teams at the junior or senior level, aged 13–39 years (n=938), and age‐group matched, randomly selected population‐based controls (n=900) were invited to participate. From the screening data, a random sample of athletes (n=186) and controls (n=145) were subjects for a clinical interview. More athletes in leanness sports (46.7%) had clinical EDs than athletes in non‐leanness sports (19.8%) and controls (21.4%) (P<0.001). Variables predicting clinical EDs, and thus candidates for valid screening procedures, were menstrual dysfunction in leanness athletes, self‐reported EDs in non‐leanness athletes, and self‐reported use of pathogenic weight control methods in controls. Hence, statistically based risk factors are not universally valid, but specifically related to athletes and non‐athletes, respectively.

The female athlete triad (Triad), links low energy availability (EA), with menstrual dysfunction (MD), and impaired bone health. The aims of this study were to examine associations between EA/MD and energy metabolism and the prevalence of Triad-associated conditions in endurance athletes. Forty women [26.2 ± 5.5 years, body mass index (BMI) 20.6 ± 2.0 kg/m(2), body fat 20.0 ± 3.0%], exercising 11.4 ± 4.5 h/week, were recruited from national teams and competitive clubs. Protocol included gynecological examination; assessment of bone health; indirect respiratory calorimetry; diet and exercise measured 7 days to assess EA; eating disorder (ED) examination; blood analysis. Subjects with low/reduced EA (< 45 kcal/kg FFM/day), had lower resting metabolic rate (RMR) compared with those with optimal EA [28.4 ± 2.0 kcal/kg fat-free mass (FFM)/day vs 30.5 ± 2.2 kcal/kg FFM/day, P < 0.01], as did subjects with MD compared with eumenorrheic subjects (28.6 ± 2.4 kcal/kg FFM/day vs 30.2 ± 1.8 kcal/kg FFM/day, P < 0.05). 63% had low/reduced EA, 25% ED, 60% MD, 45% impaired bone health, and 23% had all three Triad conditions. 53% had low RMR, 25% hypercholesterolemia, and 38% hypoglycemia. Conclusively, athletes with low/reduced EA and/or MD had lowered RMR. Triad-associated conditions were common in this group of athletes, despite a normal BMI range. The high prevalence of ED, MD, and impaired bone health emphasizes the importance of prevention, early detection, and treatment of energy deficiency.