Association of daily sitting time and leisure-time physical activity with body fat among U.S. adults.

Background: Prolonged sitting and reduced physical activity lead to low energy expenditures. However, little is known about the joint impact of daily sitting time and physical activity on body fat distribution. We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.

Resistance Training Recommendations for Children and Adolescents With Cystic Fibrosis-Related Diabetes.

Cystic fibrosis (CF) is the most prevalent hereditary life-threatening disease in the Caucasian population. With the improvement in clinical care, individuals with CF are living longer, and CF-related diabetes (CFRD) has emerged as a major complication. The diagnosis of CFRD is associated with shortening survival, increasing morbidity, worsening physical capacity, and body composition.

Physical demands and physiological strain of American football referees while officiating.

Objectives: Certain occupations are associated with greater risk of triggering a sudden cardiac event because of high levels of physical exertion and extreme thermal environments in which they occur. The extent to which sports officials--particularly high school (HS) American football referees--experience these conditions is unknown. Forty-six male HS officials (72% White/Caucasian; age = 48 ± 12 years, body mass index = 31.

Comparison of Bioelectrical Impedance Analysis with DXA in Adolescents with Cystic Fibrosis before and after a Resistance Training Intervention.

Background: The purpose of this pilot study was to compare body composition metrics obtained by two portable bioelectrical impedance analysis (BIA) devices with dual-energy X-ray absorptiometry (DXA) among adolescents with cystic fibrosis (CF) before and after a resistance exercise training program.

Methods: Participants with CF were assessed using DXA, single-frequency BIA (SFBIA), and multiple-frequency BIA (MFBIA) to quantify percent body fat (%Fat), fat mass (FM), and fat-free mass (FFM) at baseline and after a home-based resistance training intervention comprised of 36, 1 h sessions completed in 12-14 weeks. Repeated measures analysis of variance, paired samples -tests, Cohen's d effect sizes, and Pearson's correlations were used to compare differences between and within methods at baseline and post-intervention.

Feasibility and Efficacy of Telehealth-Based Resistance Exercise Training in Adolescents with Cystic Fibrosis and Glucose Intolerance.

The aims of this study were to (1) determine the feasibility of a home-based resistance exercise training (RET) program in patients with cystic fibrosis and impaired glucose tolerance using virtual personal training and (2) observe the effects completion of the RET program had on glucose metabolism, pulmonary function, body composition, and physical fitness. The feasibility of the program was defined as 80% compliance. Ten participants (15.

The Application of Exercise Training for Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) is the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after the exclusion of other causes. It is associated with pain, paresthesia, sensory loss, muscle atrophy with fat infiltration, and muscular dysfunction typically starting distally in the feet and progressing proximally. Muscle deterioration within the leg and foot can lead to muscle dysfunction, reduced mobility, and increases the risk of disability, ulceration, and amputation.

Vagally Derived Heart Rate Variability and Training Perturbations With Menses in Female Collegiate Rowers.

Introduction: The parasympathetically derived marker of heart rate variability, root mean square of successive R-R differences (RMSSD), and the daily fluctuations as measured by the coefficient of variation (RMSSDCV) may be useful for tracking training adaptations in athletic populations. These vagally derived markers of heart rate variability may be especially pertinent when simultaneously considering a female athlete's menstrual cycle.

Purpose: The purpose of this study was to observe the perturbations in RMSSDCV, while considering RMSSD, across a season in the presence and absence of menses with training load in female collegiate rowers.

Agreement Between A 2-Dimensional Digital Image-Based 3-Compartment Body Composition Model and Dual Energy X-Ray Absorptiometry for The Estimation of Relative Adiposity.

The purpose of this study was to compare relative adiposity (%Fat) derived from a 2-dimensional image-based 3-component (3C) model (%Fat) and dual-energy X-ray absorptiometry (DXA) (%Fat) against a 5-component (5C) laboratory criterion (%Fat). 57 participants were included (63.2% male, 84.

The Utility of Body Composition Assessment in Nutrition and Clinical Practice: An Overview of Current Methodology.

Body composition is a key component for maintaining good general health and longevity. It can be influenced by a variety of factors, including genetics, environment, and lifestyle choices. The assessment of body composition is an essential tool for nutrition specialists to effectively evaluate nutritional status and monitor progression during dietary interventions.

Generalized Equations for Predicting Percent Body Fat from Anthropometric Measures Using a Criterion Five-Compartment Model.

Introduction: Anthropometric-based equations are used to estimate percent body fat (%BF) when laboratory methods are impractical or not available. However, because these equations are often derived from two-compartment models, they are prone to error because of the assumptions regarding fat-free mass composition. The purpose of this study was to develop a new anthropometric-based equation for the prediction of %BF, using a five-compartment (5C) model as the criterion measure.

Utilizing a Novel 2D Image Processing System for Relating Body Composition Metrics to Performance in Collegiate Female Rowers.

The purpose of this study was to determine if rowing performance was associated with fat mass (FM) or fat-free mass (FFM) measured using a novel 2D digital image analysis system. Nineteen female rowers (ages = 20.3 ± 1.

Validity of a 3-compartment body composition model using body volume derived from a novel 2-dimensional image analysis program.

Background/objectives: The purpose of this study was: (1) to compare body volume (BV) estimated from a 2-dimensional (2D) image analysis program (BV), and a dual-energy x-ray absorptiometry (DXA) equation (BV) to an underwater weighing (UWW) criterion (BV); (2) to compare relative adiposity (%Fat) derived from a 3-compartment (3C) model using BV (%Fat), and a 4-compartment (4C) model using BV (%Fat) to a 4C criterion model using BV (%Fat).

Subject/methods: Forty-eight participants were included (60% male, 22.9 ± 5.

Heart-Rate Variability Recording Time and Performance in Collegiate Female Rowers.

Purpose: To assess the agreement of the root mean square of successive R-R interval (RMSSD) values when recorded immediately upon waking to values recorded later in the morning prior to practice, and to determine the associations of the RMSSD recordings with performance outcomes in female rowers.

Methods: A total of 31 National Collegiate Athletic Association Division I rowers were monitored for 6 consecutive days. Two seated RMSSD measurements were obtained on at least 3 mornings using a smartphone-based photoplethysmography application.

Comparison of Heart Rate Variability Responses to Varying Resistance Exercise Volume-Loads.

: The aim of this study was to compare the effects of low ([LV]; 4 total sets), moderate ([MV]; 8 total sets), and high set volumes ([HV]; 12 total sets) in acute full-body resistance exercise sessions on post-exercise parasympathetic reactivation measured using RMSSD. : Ten resistance-trained participants (25.8 ± 6.

Accuracy of a Mobile 2D Imaging System for Body Volume and Subsequent Composition Estimates in a Three-Compartment Model.

Purpose: The purpose of the study was to compare a single two-dimensional image processing system (IMAGE) to underwater weighing (UWW) for measuring body volume (BV) and subsequently estimating body fat percentage (%Fat), fat mass (FM), and fat-free mass (FFM) via a 3-compartment (3C) model.

Methods: A sample of participants age 18-39 yr was recruited for this study (n = 67, 47.8% female).

Associations between Multimodal Fitness Assessments and Rowing Ergometer Performance in Collegiate Female Athletes.

The purpose was to examine the association of critical power from a three-minute all-out row (CP) and peak power from a one-stroke maximum test (1-Stroke) with laboratory-based fitness assessments (peak oxygen consumption [V.O] and Wingate anaerobic test [WAnT]) and 6000 m (6K) and 2000 m (2K) rowing ergometer performance. Thirty-one female collegiate rowers (20.

Validity of Smartphone Heart Rate Variability Pre- and Post-Resistance Exercise.

The aim was to examine the validity of heart rate variability (HRV) measurements from photoplethysmography (PPG) via a smartphone application pre- and post-resistance exercise (RE) and to examine the intraday and interday reliability of the smartphone PPG method. Thirty-one adults underwent two simultaneous ultrashort-term electrocardiograph (ECG) and PPG measurements followed by 1-repetition maximum testing for back squats, bench presses, and bent-over rows. The participants then performed RE, where simultaneous ultrashort-term ECG and PPG measurements were taken: two pre- and one post-exercise.

Changes in Heart Rate Variability and Fatigue Measures Following Moderate Load Resistance Exercise.

The purpose of this study was to determine the relationship between changes in heart rate variability (HRV), neuromuscular performance, and fatigue biomarkers in response to a resistance exercise bout. The root mean square of successive RR interval differences (RMSSD), neuromuscular performance - isometric handgrip (IHG), countermovement jump (CMJ), mean propulsive velocity (MPV) - metabolic stress (lactate [Lac]) and inflammation (interleukin-6 [IL-6]) were measured in 30 subjects who performed 6×10 back squat (BS), 3×10 bench press (BP), and 3×10 bent-over rows (BR) at 70% of 1-repetition maximum (1RM). The RMSSD, neuromuscular performance, and biomarkers were measured 10 min pre-exercise and 30 min post-exercise (Post); HRV and Lac were also measured immediately post-exercise (Post).

Agreement between supine and standing bioimpedance spectroscopy devices and dual-energy X-ray absorptiometry for body composition determination.

Background: Research comparing bioimpedance spectroscopy (BIS) to dual-energy X-ray absorptiometry (DXA) is limited, especially with newer BIS devices that take measures in a standing position instead of the traditional supine position.

Purpose: The purpose of this study was to compare a standing BIS device (BIS ) and a supine BIS device (BIS ) to DXA for measuring body fat percentage (BF%), fat mass (FM) and fat-free mass (FFM) in a cohort of male and female subjects displaying a wide range of ages and BMI levels.

Methods: Ninety-five subjects (30 ± 15 years, 170 ± 8·0 cm, 72·6 ± 14·8 kg) participated in the study.

Age-Based Prediction of Maximal Heart Rate in Children and Adolescents: A Systematic Review and Meta-Analysis.

: Maximal heart rate (MHR) is an important physiologic tool for prescribing and monitoring exercise in both clinical and athletic settings. However, prediction equations developed in adults may have limited accuracy in youth. The purpose of this study was to systematically review and analyze the available evidence regarding the validity of commonly used age-based MHR prediction equations among children and adolescents.

Heart Rate Variability and Stress Recovery Responses during a Training Camp in Elite Young Canoe Sprint Athletes.

Training camps are typical in elite Canoeing preparation, during which, the care to assure adaptation to avoid undesired fatigue is not always present. This study aimed identifying a specific sex response in perceived training loads, recovery and stress balance, and cardiac autonomic responses. Twenty-one elite athletes (11 males and 10 females) of the Portuguese Canoeing National team participated in the investigation.

The Accuracy of Acquiring Heart Rate Variability from Portable Devices: A Systematic Review and Meta-Analysis.

Background: Advancements in wearable technology have provided practitioners and researchers with the ability to conveniently measure various health and/or fitness indices. Specifically, portable devices have been devised for convenient recordings of heart rate variability (HRV). Yet, their accuracies remain questionable.

Heart Rate Variability Responses to an Undulating Resistance Training Program in Free-Living Conditions: A Case Study in a Collegiate Athlete.

The purpose of this case study was to evaluate the response in heart rate variability via the parasympathetically-mediated metric of the log-transformed root mean square of successive R-R interval differences (lnRMSSD) to weekly variations in total volume-load (TVL) during an 18-week periodized strength training program in a competitive collegiate hockey athlete. The program consisted of three 60⁻90 min full-body exercise sessions per week with at least 24-h of rest between each session. Daily lnRMSSD measurements were taken immediately after waking using a validated smartphone application and the pulse-wave finger sensor.

Field-Based Performance Tests Are Related to Body Fat Percentage and Fat-Free Mass, But Not Body Mass Index, in Youth Soccer Players.

The primary aim of this study was to determine the association between body composition and performance outcomes in youth soccer players. Twenty-five competitive male youth soccer players (age = 13.7 ± 0.