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…

Impedance (Z), resistance (R), reactance (Xc), and phase angle (PhA) are sensitive to shifts in fluid between intra- and extracellular compartments, as would occur with nutrient uptake into skeletal muscle, but remains largely unexplored. To explore the sensitivity of whole-body and segmental (arms, legs, trunk) bioimpedance to acute feeding, 27…

Background: Measures that assess muscle strength and its development, either voluntarily or involuntarily, are important in the clinical and research context. The main aim of this study was to verify the interday reliability and the minimum detectable change (MDC) of the knee extensors muscles torque using evoked contractions and explosive…

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…

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…

Anaerobic capacity is an important determinant of swimming performance, and a feasible land-based test for measuring swim-specific anaerobic capacity is lacking. This study assessed the test-retest reliability of a swim-specific modification of the Wingate anaerobic capacity test: the WAnT-Swim. Ten competitive and fitness swimmers from the local…

This study compared criterion to minimally invasive, practical measures of core (T[subscript c]) and skin (T[subscript sk) temperature during 30 min of moderate-intensity cycle exercise in a heat chamber (35°C, 60% rH). T[subscript c] was monitored using a core temperature pill (T[subscript c](Pill))] and tympanic thermometer (T[subscript c(Tymp))…

Obesity has been found to relate to urine-assessed hypohydration risk at the population level, but studies have often failed to account for lean mass, which influences urine solute load. Adults (n = 8,699) from the National Health and Nutrition Examination Survey were categorized as hypohydrated or not using five urine-based methods. Hypohydration…

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.…

Many sports demand high forces at high movement speeds. Joint power combines these two measures and is frequently analyzed by isokinetic tests. However, various concepts of assessing joint power lead to conflicting results. The aim was to examine different methods to calculate peak power during isokinetic knee tests of sixty-one healthy male…