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.…

Excess adipose tissue may impact the motor performance of youth. Therefore, the current study examined: (1) if adiposity influenced performance in the jump and reach and 30-yard dash; and (2) if maturation predicted motor performance. Participants (N = 267) included girls aged 8 to 16 years. Latent growth curves were used to assess changes in…

We developed plank test standards, based on trunk lean mass-to-fat mass (LM/FM) ratio, in a sample of healthy Portuguese 10--18 year olds (n = 474, 46.4% female). Height and weight were measured and muscular endurance was assessed using the prone plank test. Trunk LM/FM ratio was determined using dual-energy x-ray absorptiometry. Plank standards…

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…

We designed grip strength standards for youth by back-extrapolating cutpoints based on weakness at age 65. Existing standards, based on insufficient bone mineral content (BMC), were also compared in a nationally representative sample. Altogether, 6837 participants (n = 2199 [less than or equal to] 18.9 years of age) from the National Health and…

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…

Identification of cardiometabolic risk (CMR) in U.S. younger population by assessing muscular strength via handgrip (HG) dynamometry may aid in prevention efforts. Currently, no nationally representative HG cut-points are available for identifying increased CMR in U.S. adolescents or young adults. In this study, we propose normalized grip strength…

The Michigan State University Motor Performance Study (MPS) was initiated in 1967 and lasted 32 years. Three central components existed: 1) Educational component, in which students experienced applied work with youth; 2) Instructional component, whereby enrolled youth received sport-specific skill instruction; and 3) Research component. The…

Purpose: To develop models to estimate aerobic fitness (VO[subscript 2]max) from PACER performance in 10- to 18-year-old youth, with and without body mass index (BMI) as a predictor. Method: Youth (N = 280) completed the PACER and a maximal treadmill test to assess VO[subscript 2]max. Validation and cross-validation groups were randomly formed to…

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…

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…

In this study the authors examine the test-retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria-Kalamen stair test, and (c) the Wingate Anaerobic Test. The…