The purpose was to evaluate reliability of measurements during drop jump (DJ) and magnitude of differences in vertical jump height (VJH) when calculated using two variables: time-in-the-air and center-of-mass velocity. Thirty-seven handball players performed three single-leg and double-leg DJs on a portable force plate during two sessions. Sixteen…

The purpose was to evaluate the intra- and inter-session reliability of hip isometric strength assessment using a frame-stabilized dynamometer (FSD) and to compare the results in the hip adduction (ADD) and abduction (ABD) strength assessment using handheld dynamometer (HHD). Twenty participants (24.2 [2.6] years, 69.3 [10.0] kg) underwent testing…

A universal approach to characterizing sport-related physical activity (PA) types in sport settings does not yet exist. Young adults (n = 30), 19-33 years, engaged in a 15-min activity session, performing warm-ups, 3-on-3 soccer, and 3-on-3 basketball. Videos were recorded and manually coded as criterion PA types (walking, running, jumping, rapid…

The aim was to establish which postural and physical activity outcomes are comparable across different accelerometer brands worn on the thigh when processed using open-source methods. Twenty participants wore four accelerometers (Axivity, ActiGraph, activPAL, GENEActiv) for three free-living days. Postural and physical activity outputs (average…

This study examined the test-retest reliability of the standing long jump (SLJ) and the countermovement jump (CMJ) following consistent and non-consistent attentional focus cuing instructions in physically active young adults (n = 30). The systematic error (as standardize change in mean), random error (as typical error), the Bland and Altman…

This study evaluated the reliability of the portable Lactate Pro 2 analyzer (LP2), and its validity compared to a laboratory-based analyzer, YSI 1500 Sport (YSI). Blood samples (n = 258) were collected during 44 graded incremental rowing tests, with data from 17 tests used to quantify load, heart rate, and oxygen consumption at lactate threshold.…

This study explored the influence of different take-off thresholds on the reliability and magnitude of countermovement jump (CMJ) performance variables. Twenty-three men were tested on two separate sessions. CMJ performance variables were obtained against three external loads (0.5-30-60 kg) using three take-off thresholds: 10 N (arbitrary value of…

This study evaluated the estimated jump height (JH) differences between an inertial measurement unit (IMU), a linear position transducer (LPT), and two force plates (FPs). Thirty-eight student-athletes were recruited to perform vertical jumps that were simultaneously recorded using two dual-axis FPs (criterion measure), an LPT and an IMU.…

The aim of the present study was to investigate a think aloud protocol as a novel way to measure indicators of self-control during acts of physical persistence. Using a within-person design, 35 participants (9 males, 26 females) completed two wall-sit persistence tasks, one employing a think aloud protocol, and the other silent. A two-way mixed…

Research tracking sport participation from youth to adulthood is relatively rare, as is research that tracks youth sport participation with regard to adult physical activity (PA) levels, especially in the United States. Aims of this study were: 1) To investigate the degree to which sport participation tracked across youth, adolescence, and early…

The aim of the study was to determine the convergent validity of a portable polysomnograph and an accelerometer for measuring sleep efficiency and movement in college students. Volunteers were 29 healthy students (males = 15, females = 14) who simultaneously wore the Nox T3 portable polysomnograph and the ActiGraph wGT3X-BT accelerometer. Both…

The Child-Focused Injury Risk Screening Tool (ChildFIRST) is a process-based assessment including 10 movement skills with 4 associated evaluation criteria. The ChildFIRST has been validated by a group of experts to evaluate movement competence and injury risk in 8-12-year-olds. The purpose of this study is to evaluate the reliability of the…

Anthropometry is important for predicting sports performance. While 3-dimensional (3D) body scanners increase the feasibility of anthropometric assessment, reliability data on athletes are lacking. The aim of this study was to determine the test-retest reliability of a portable, single-camera 3D body scanning system (Styku S100) to assess…

Using a multiphase approach, the purpose of the present study was to develop a psychometrically sound questionnaire to measure protégés' perceptions of peer athlete mentoring functions. Phase 1 consisted of three stages: (a) item development, (b) assessment of content validity via think-aloud interviews with peer mentored athletes, and (c)…

Despite proprietary algorithms to account for differences, output from activity trackers worn on different wrists may not be comparable because individuals vary in their reliance on each hand during free-living activities. Participants (n = 48) wore Fitbit Flex or Flex2 monitors on each wrist for three days. T tests, equivalence tests, and…