Field-based tests of aerobic fitness that can be administered quickly and do not require maximal effort are desirable. The purpose was to develop and validate quarter-mile walk tests for 10--13-year-olds. Participants (N = 59) walked one mile on two different days. Walk times, heart rates, body mass, physical activity, and aerobic fitness were…

This study compared the weekly training load (TL) variation across different measures. Fifty-two runners reported their heart rate and distance ran for each training session during four weeks of training. Heart rate measures were used to calculate the weekly TRaining IMPulse (W-TRIMP), whereas the distance ran was used to calculate the weekly…

We investigated the associations and differences between dynamic strength index (DSI) calculated from different types of vertical jump (countermovement jump; CMJ and squat jump; SJ) and different isometric knee joint angles (30, 60 and 90[degrees]), and associations with force-velocity (FV) profile and its constituent variables (maximal…

Confirmatory factor analysis (CFA) is a commonly used statistical technique. Recommendations for evaluating CFA highlight scholars should outline the expected model, conduct data screening, report model estimation and evaluation, and report key information about results to provide evidence for latent variables. The purpose of the current study was…

This study aimed to develop and validate machine learning models to predict intensities in children and adolescents with cystic fibrosis (CF) across different accelerometry brands and placements. Thirty-five children and adolescents with CF (11.6 ± 2.8 yrs; 15 girls) and 28 healthy youth (12.2 ± 2.7 yrs; 16 girls) performed six activities whilst…

This study investigated whether exercise and physical activity identity are conceptually distinct factors. Undergraduate students (N = 647; M[subscript age] = 19.54 ± 1.86 years; 61% female) completed an online survey including the Exercise Identity Scale and a modified physical activity version. Confirmatory factor analysis largely supported a…

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…

Electrically evoked torque at rest (i.e., the torque produced from supramaximal stimuli applied to a resting muscle) has been shown to be related to muscle size in healthy adults, but this relationship has not been evaluated in pathological populations where atrophy is present. This study aims to evaluate the relationship between the electrically…

The heart rate variability threshold (HRVT) is a useful and inexpensive alternative to estimate the ventilatory threshold (VT). However, its validity in women remains underexplored. We investigated the agreement between HRVT and VT in young women and the influence of cardiac parasympathetic status and cardiorespiratory fitness (CRF). Sixty-one…

The flexion relaxation ratio (FRR) of the lumbar extensor muscles is often assessed in experimental and clinical studies. This study evaluated within- and between-session test--retest reliability and measurement error for different FRR formulations. Participants completed two identical data collection sessions 1-week apart. Spine flexion and…

A number of familiarization trials are needed for reliable measurement, particularly for inexperienced subjects. Researchers have studied and developed familiarization protocols that vary by exercise and study population. The pace of familiarization and fatigue may be an individual-level characteristic, so a population-level protocol may not fit…

Heart rate samples (n = 4500-8000) from wearables were compared to electrocardiography during a steady-state ruck (Ruck-S), maximal effort ruck (Ruck-M), submaximal cycle (Cycle), and Tabata Circuit. One device was worn at each location (wrist: Polar Grit-X, Garmin Fenix 6; chest-straps: Polar H10, Garmin HRM-Pro; armband: Polar Verity).…

Subtle instructional changes that direct attentional focus can lead to changes in performance, potentially hindering a fitness assessment. An external attentional focus has been found to improve motor performance, however less is known about instructional effects on performance and the physiological response during an isometric endurance test. To…

Small sample sizes contribute to several problems in research and knowledge advancement. This conceptual replication study confirmed and extended the inflation of type II errors and confidence intervals in correlation analyses of small sample sizes common in kinesiology/exercise science. Current population data (N = 18, 230, & 464) on four…

An a-posteriori multicentre reliability study was conducted to compare the reliability and magnitude of the maximum power (P[subscript max]) and optimal velocity (V[subscript opt]) between the force-power-velocity relationships during the leg cycle-ergometer and bench press throw exercises. The force-power-velocity relationships were determined in…