Using the 2017-2018 National Health and Nutrition Examination Survey (weighted population size = 35,460,209; 8-18 years old; 52.1% males), we compared the obesity prevalence in children and adolescents between body mass index-based (BMI-based) and total percent body fat-based (BF%-based, measured by the dual-energy x-ray absorptiometry) cutoffs.…

Social physique anxiety is commonly examined in exercise science to understand individuals' physical activity motivation and behavior. Although a 12-item and 9-item version of the Social Physique Anxiety Scale exists, a 7-item version has become a popular tool to measure this construct despite the need to further examine its measurement…

We developed age- and sex-specific smoothed percentiles for vertical and long jump, as well as vertical jump power, in healthy 10-18 year olds (n = 529, 47.1% female). Jump height and distance were measured and vertical jump power was assessed via mechanography. LMS regression was used to create smoothed age-specific reference curves, separated by…

This study evaluated test-equating methods to enable comparisons and conversions between the vertical jump (VJ) and standing long jump (SLJ) tests. A total of 528 youth (280 males) performed VJ and SLJ, and their scores were randomly split as the calibration (C) sample (n = 478) and cross-validation (CV) sample (n = 50). SLJ scores of the C sample…

Childhood physical fitness relative to adult health outcomes coupled with scant longitudinal research indicates that tracking of fitness components throughout childhood/adolescence is imperative. The study examined the stability/tracking of 9 measures of fitness for boys and girls at 5 points throughout childhood/adolescence. Tracking coefficients…

Incorporation of the vertical jump (VJ) test in health-related fitness batteries is predicated on the availability of prediction equations to accurately estimate VJ power. The purpose was to develop and validate a generalizable equation to estimate VJ power from VJ height, body mass, age, and sex in 10- to 18-year-olds. The sample (N = 529)…

This study examined the predictive validity of musculoskeletal fitness tests for identifying sarcopenia in youth. The sample was 529 participants age 10 to 18 years. Indices included: total lean body mass (LBM) normalized for height (LBM index, LBMI, kg/m2), appendicular LBMI (aLBMI, kg/m[superscript 2]), and LBM to fat body mass (FBM) ratio…

The study compared the agreement, internal consistency, and measurement stability of the GE iDXA, BOD POD, and InBody 720. Body composition of 43 men and 37 women (31.4 ± 10.7 years; 90% Caucasian and 10% other) was assessed in triplicate using each method over two different days. Mean percent body fat (% BF) of the participants was different for…

This study summarized protocols in the "Lisbon Study for the Development and Evaluation of Musculoskeletal Fitness Standards in Youth" and assessed associations between fitness assessments and health outcomes. The sample was 529 children and adolescents (10 to 18 yr). The fitness assessments included handgrip, vertical jump, long jump,…

The aim of this study was to investigate differences between estimates of sedentary behavior and physical activity (PA) from the International Physical Activity Questionnaire (IPAQ) and accelerometry in undergraduate students. 91 students participated in the study. Sedentary behavior and PA were objectively measured by an accelerometer for 7 days…

An age and body mass handicap has been previously developed and validated for the 5-kilometer (5K) run. The purpose of this study was to develop a similar handicap for the marathon but with a different age adjustment based on deviations from age group world best marathon times within each sex. The resulting handicap allowed finish time comparisons…

Body mass index is a common proxy for proportion of body fat. However, body mass index may not classify youth similarly across ages and ethnicities. We used sex- and ethnic-specific receiver operating characteristic curves to determine how obesity classifications compared between body mass index and dual energy x-ray absorptiometry-based body fat…

The purpose of this study was to analyze the kinematic variables that determine the performance of the standing long jump in children 6- to 12-years-old. There were 121 healthy children (58 girls) recorded while they performed the standing long jump test. All kinematic variables showed a significant correlation with calculated jump distance and…

Previous research has used cluster analysis to examine how social physique anxiety (SPA) combines with motivation in physical education. This study utilized a more advanced analytic approach, latent profile analysis (LPA), to identify profiles of SPA and motivation regulations. Students in grades 9-12 (N = 298) completed questionnaires at two time…

The purpose of this study was to develop a step test with a personalized step rate and step height to predict cardiorespiratory fitness in 80 college-aged males and females using the self-reported perceived functional ability scale and data collected during the step test. Multiple linear regression analysis yielded a model (R = 0.90, SEE = 3.43…