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…

Accurate body composition assessment, which includes fat mass (adipose tissue mass, FM), fat-free mass (FFM), and percent fat mass (%FM) is needed to evaluate health and treatment efficacy. The current study compared body composition estimates obtained from the Norland Elite® DXA, BodPod®, and iDXA® before and after a 12-week exercise intervention…

As part of a validation study of the Exercise Planning and Scheduling (EPS), and Goal-Setting (EGS) Scales, which were translated from English to Brazilian Portuguese, we aim to: present evidence of reliability and validity for the translated scale; and, explore the effects of non-labeled response categories of rating scales. The sample comprised…

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))…

This study examined the validity and reliability of a 30-second running sprint test using two non-motorized treadmills compared to the established Wingate Anaerobic Test. Twenty-four participants completed three sessions in a randomized order on a: (1) manual mode treadmill (Woodway); (2) specialized interval training treadmill (HiTrainer); and…

This study establishes tri-axial activity count (AC) cut-points for the GT3X+ accelerometer to classify physical activity intensity in overweight and obese adults. Further, we examined the accuracy of established and novel energy expenditure (EE) prediction equations based on AC and other metrics. "Part 1": Twenty overweight or obese…

Previous activity classification studies have typically been performed on normal weight individuals. Therefore, it is unclear whether a generic classification algorithm could be developed that would perform consistently across individuals who fall within different BMI categories. Acceleration data were collected from the hip and ankle joints of 50…

To examine the reproducibility of three measurement techniques used to determine creatine kinase, interleukin-6 and high-sensitivity C-reactive protein, 50 participants had blood samples taken on two occasions. Fingertip plasma samples were analysed using the Reflotron for CK determination. Venous blood samples collected into serum separator tubes…

The purpose of the present study was to examine the factorial and convergent validity of the German translation of the Exercise Identity Scale (EIS; Anderson & Cychosz, 1994). We introduce a bifactor model as a possible alternative to the previously discussed one- and two-factor models. Using an online study with 530 participants, our results…

The purpose of the current study was to determine the accuracy of the Fitbit Charge HR and Hexoskin smart shirt. Participants (n = 32, age: 23.5 ± 1.3 years) wore a Fitbit and Hexoskin while performing 14 activities in a laboratory and on a track (lying, sitting, standing, walking various speeds and inclines, jogging, and cycling). Steps, kcals,…

This study examined (a) the validity of two accelerometers (ActiGraph GT3X [ActiGraph LLC, Pensacola, FL, USA] and activPAL [PAL Technologies Ltd., Glasgow, Scotland]) for the assessment of sedentary behavior; and (b) the variations in assessment accuracy by setting minimum sedentary bout durations against a proxy for direct observation using an…

An equation published by Loftin, Waddell, Robinson, and Owens (2010) was cross-validated using ten normal-weight walkers, ten overweight walkers, and ten distance runners. Energy expenditure was measured at preferred walking (normal-weight walker and overweight walkers) or running pace (distance runners) for 5 min and corrected to a mile. Energy…

The purpose of this study was to provide three construct validity evidence for using fitness center attendance electronic records to objectively assess the frequency of leisure-time physical activity among adults. One hundred members of a fitness center (45 women and 55 men; aged 18 to 64 years) completed a self-report leisure-time physical…

The purpose of this study was to develop an age-generalized regression model to predict maximal oxygen uptake (VO sub 2 max) based on a maximal treadmill graded exercise test (GXT; George, 1996). Participants (N = 100), ages 18-65 years, reached a maximal level of exertion (mean plus or minus standard deviation [SD]; maximal heart rate [HR sub…

This study was designed to develop a single-stage submaximal treadmill jogging (TMJ) test to predict VO[subscript 2]max in fit adults. Participants (N = 400; men = 250 and women = 150), ages 18 to 40 years, successfully completed a maximal graded exercise test (GXT) at 1 of 3 laboratories to determine VO[subscript 2]max. The TMJ test was completed…