Jeffrey R. Stout

Jeffrey R. Stout
University of Central Florida | UCF · School of Kinesiology and Physical Therapy

PhD

About

535
Publications
235,281
Reads
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13,098
Citations
Additional affiliations
August 2018 - August 2019
University of Central Florida
Position
  • Head of Faculty
July 2018 - July 2019
University of Central Florida
Position
  • Managing Director
Description
  • New College of Health Professions and Sciences will house the new School of Kinesiology and Physical Therapy July 2nd, 2018.
July 2018 - October 2019
University of Central Florida
Position
  • Managing Director

Publications

Publications (535)
Article
Full-text available
This position stand aims to provide an evidence-based summary of the energy and nutritional demands of tactical athletes to promote optimal health and performance while keeping in mind the unique challenges faced due to work schedules, job demands, and austere environments. After a critical analysis of the literature, the following nutritional guid...
Article
Full-text available
Purpose: Previous studies have suggested that beta-alanine supplementation may benefit exercise performance, but current evidence regarding its effects on body composition remains unclear. This systematic review and meta-analysis aimed to investigate the effects of beta-alanine supplementation on body composition indices. Methods: Online databas...
Article
Full-text available
The long-term impact of weight cycling on health status, eating habits, physical activity, and the lifestyle of former combat sports athletes is still insufficiently explored. Therefore, a novel questionnaire in English, Portuguese, Spanish and Croatian language was constructed. To determine the reliability and the content/face validity, a total of...
Article
Full-text available
Introduction: The addition of protein to a carbohydrate solution has been shown to effectively stimulate glycogen synthesis in an acute setting and enhance exercise performance in a subsequent bout of exhaustive exercise. This study examined the effects of carbohydrate-protein (CHO-P), carbohydrate (CHO), and placebo (PLA) within a 2-hour recovery...
Preprint
BACKGROUND Physical activity (PA) is vital for attenuating the aging-related physiological and functional declines in women aged 60 years or above. However, little is known about the objectively assessed PA behavior in older women during the COVID-19 pandemic and its association with socio-demographics, health and physical function. OBJECTIVE This...
Article
Full-text available
The immune function is closely related to iron (Fe) homeostasis and allostasis. The aim of this bioinformatics-assisted review was twofold; (i) to update the current knowledge of Fe metabolism and its relationship to the immune system, and (ii) to perform a prediction analysis of regulatory network hubs that might serve as potential biomarkers duri...
Article
The purpose of this study was to evaluate the effects of environmental conditions on running performance and performance efficiency index (Effindex). Performance data recorded using Polar Team Pro sensors from eight collegiate female soccer players in nine matches were analyzed during the 2019 competitive season. Effindex and running performance, i...
Presentation
Full-text available
Promising technologies, which are simple, portable, quick, non-invasive, and inexpensive, may open new horizons on fall risk assessments and provide important information for older adults. We used a mixed-methods approach to examine the feasibility and acceptability of technology-based fall risk assessments, including the BTrackS Balance System, Bi...
Presentation
Full-text available
One-third of older adults have a discrepancy between perceived and physiological fall risks or maladaptive fall risk appraisal (FRA). Older adults who report high fear of falling and overestimate their physiological fall risk are less likely to participate in physical activity (PA). Limited data suggest the interrelation between fall risk appraisal...
Presentation
Full-text available
One-third of older adults have maladaptive fall risk appraisal (FRA), a condition in which there is a discrepancy between perceived fall risk or levels of fear of falling (FOF) and physiological fall risk (balance performance). We aimed to examine the associations among FRA, body composition, and physical activity (PA) using Assistive Health Techno...
Presentation
Full-text available
COVID-19 pandemic has caused a severely detrimental effect on the physical, psychological, and functional well-being of older adults by forcing them to limit their social activities. This study investigates the amount and intensity of daily physical activity (PA) in older adults, living under the social distancing guidelines during COVID-19 pandemi...
Presentation
Full-text available
Fear of falling is common in the older adult population with an estimated 43% being affected. We aimed to examine the associations among fear of falling, fall risk, depression, and anxiety in community-dwelling older adults. For this study 124 participants ranging from 60 to 96 years of age were recruited from the community settings in Central Flor...
Article
Full-text available
The mechanical properties of knee flexors and extensors in 15 collegiate male soccer players following different warm-up protocols [small-sided games (SSG), dynamic (DYN), and plyometric (PLY)] were evaluated. Tensiomyography (TMG) was used to assess contraction time (Tc), delay time (Td) and maximal displacement (Dm) of the rectus femoris (RF) and...
Article
Full-text available
Based on a comprehensive review and critical analysis of the literature regarding the effects of sodium bicarbonate supplementation on exercise performance, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Sup...
Article
Full-text available
Creatine (Cr) and phosphocreatine (PCr) are physiologically essential molecules for life, given they serve as rapid and localized support of energy- and mechanical-dependent processes. This evolutionary advantage is based on the action of creatine kinase (CK) isozymes that connect places of ATP synthesis with sites of ATP consumption (the CK/PCr sy...
Article
Herda, AA, Smith-Ryan, AE, Kendall, KL, Cramer, JT, and Stout, JR. Evaluation of high-intensity interval training and beta-alanine supplementation on efficiency of electrical activity and electromyographic fatigue threshold. J Strength Cond Res 35(6): 1535-1541, 2021-The purpose of this study was to determine the effects of high-intensity interval...
Article
Full-text available
Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass an...
Article
Background: The present study aimed to determine whether energy drink (ED) formulas containing 140 and 100 mg of caffeine have the potential to alter excess postexercise oxygen consumption (EPOC) responses after an incremental exercise test in males and females. Materials and Methods: Participants were submitted to incremental tests to exhaustion a...
Article
Full-text available
Creatine (Cr) is a ubiquitous molecule that is synthesized mainly in the liver, kidneys, and pancreas. Most of the Cr pool is found in tissues with high-energy demands. Cr enters target cells through a specific symporter called Na+/Cl−-dependent Cr transporter (CRT). Once within cells, creatine kinase (CK) catalyzes the reversible transphosphorylat...
Article
Full-text available
Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store crea...
Preprint
BACKGROUND One-third of older adults have maladaptive fall risk appraisal (FRA), a condition in which there is a discrepancy between a level of fear of falling (FOF) and physiological fall risk (balance performance). Older adults who overestimate their physiological fall risk and report high fear of falling are less likely to participate in physica...
Article
Full-text available
Background One-third of older adults have maladaptive fall risk appraisal (FRA), a condition in which there is a discrepancy between the level of fear of falling (FOF) and physiological fall risk (balance performance). Older adults who overestimate their physiological fall risk and report a high FOF are less likely to participate in physical activi...
Article
Full-text available
Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: 1. Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use...
Article
Full-text available
Background: Thermogenic fitness drink formulas (TFD) have been shown to increase energy expenditure and markers of lipid metabolism. The purpose of the current study was to compare TFD formulas containing different caffeine concentrations versus a placebo drink on energy expenditure and lipid metabolism at rest and during exercise. Methods: Thir...
Article
Purpose of review: The interest in the use of beta-hydroxy-beta-methylbutyrate (HMB) as an intervention to prevent and treat sarcopenia has increased over recent years. The purpose of this review is to explore recent evidence pertaining to the mechanism of action of HMB and how this may influence changes in lean mass and strength in older persons...
Article
Full-text available
This study examined the cardiac autonomic responses, as measured by heart rate variability (HRV), during cycling exercise and short-term rest after energy drink consumption. Seventeen participants (seven males and 10 females; age: 22.8 ± 3.5 years; BMI: 24.3 ± 3.3 kg/m2) completed this double-blind, placebo-controlled, counterbalanced crossover des...
Article
The purpose of this trial was to examine the effects of self-selected exercise intensities plus either whey protein or placebo supplementation on vital signs, body composition, bone mineral density, muscle strength, and mobility in older adults. A total of 101 participants aged 55 years and older (males [ n = 34] and females [ n = 67]) were evaluat...
Article
Full-text available
The purpose of this study was to assess the maturity-related differences in the aerobic and anaerobic adaptations to sprint interval training (SIT) among youth male athletes. Twenty-seven youth male athletes were assessed for years from peak height velocity (PHV) and classified into prepubescent (PRE, n = 7, years from PHV = -2.21 ± 0.47 years), pe...
Article
A one-group pre/posttest study was conducted to examine the feasibility and effect size of an 8-week physio-feedback and exercise program (PEER) on improving balance, muscle strength, and fall risk. Nineteen participants (mean age = 76 years) received the intervention, which included visual physio-feedback by the BTrackS™ Assess Balance System, cog...
Article
The current study aimed to categorize fall risk appraisal and quantify discrepancies between perceived fall risk measured subjectively using the short Fall Efficacy Scale-International and physiological fall risk measured objectively using the portable BTrackS™ Assess Balance System. One hundred two community-dwelling older adults were evaluated in...
Article
Post-activation potentiation likely acutely improves power-based performance; however, few studies have demonstrated improved endurance performance. Forty collegiate female rowers performed isometric potentiating (ISO), dynamic potentiating (DYN) and control (CON) warm-up protocols on a rowing ergometer, followed by a three-minute all-out test to e...
Article
Background: Sex-based differences in metabolism and morphological characteristics may result in unique exercise responses during periods of limited oxygen availability. Purpose: To evaluate the effects of moderate normobaric hypoxia on the parameters of the work-time relationship during upper body exercise in women. Materials and Methods: Thirtee...
Article
To examine the preliminary efficacy of an 8-week judo program to promote moderate-to-vigorous physical activity (MVPA) and reduce sedentary behavior (SB) in youth with Autism Spectrum Disorder (ASD). Fourteen children diagnosed with ASD participated in a weekly judo program over a period of 8 weeks. Participants wore an Actigraph accelerometer to m...
Article
Objectives: 1) examine the preliminary effectiveness of the Physio-feEdback and Exercise pRogram (PEER) for shifting maladaptive to adaptive fall risk appraisal and reducing fall risk, 2) determine the participants’ feedback and acceptability of the program. Methods: Forty-one older adults were assigned to either PEER intervention or attention cont...
Article
Full-text available
In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by fol...
Article
Full-text available
Purpose Recent evidence suggests that deception may not be necessary for placebos to improve clinical outcomes. We tested the hypothesis that placebo and open-label placebo (OLP) treatments would acutely improve strength and voluntary activation, as well as minimize neuromuscular fatigue, in untrained participants. Methods Twenty-one males (n = 11...
Article
Full-text available
Ultrasonography of the lower body typically encompasses supine rest due to fluid shifts affecting tissue size and composition. However, vastus lateralis (VL) examination is completed in the lateral recumbent position, and this positional change may influence morphology and its ability to predict function. This study aimed to examine the effect of p...
Article
The purpose of this study was to identify the effects of superficial cooling on physiological responses while training in a warm, humid environment during an international judo training camp. Sixteen judokas (8 women and 8 men) participated in the experiment. Four high-level women and four men were randomly assigned to wear a cooling vest (vest gro...
Article
Full-text available
β-alanine supplementation increases muscle carnosine content and improves anaerobic exercise performance by enhancing intracellular buffering capacity. β-alanine ingestion in its traditional rapid-release formulation (RR) is associated with the symptoms of paresthesia. A sustained-release formulation (SR) of β-alanine has been shown to circumvent p...
Article
The aim of this study was to compare muscle oxygenation of the vastus lateralis during a high-volume isokinetic resistance exercise protocol (HVP) between young adult (YA) and middle-aged adult (MA) men. Twenty recreationally trained men were assigned to either the YA (age 21.8±2.0 years, body mass 90.7±11.6 kg, body height 179±4.7 cm) or MA (age 4...
Article
Full-text available
Purpose This study evaluated the contributions of somatic maturity (years from estimated peak height velocity) and training experience as developmental indicators of muscle morphology, biomechanical parameters, and bilateral asymmetries in youth judo athletes. Methods Twenty-six judo athletes aged 8–18 years (mean ± SD; age = 12.9 ± 2.6 years, mat...
Article
Objective: The present study evaluated the effects of repeated-sprint training in normobaric hypoxia and β-alanine supplementation (BA) on aerobic and anaerobic performance in recreationally active men. Methods: Participants were randomly assigned to one of the following groups: normoxia/β-alanine (NB, n = 11), normoxia/placebo (NP, n = 8), normoba...
Article
Purpose: To examine the reliability and the maturity-related differences of fatigue thresholds (FTs) among youth males. Methods: Twenty-nine youth males (11-17 y) completed 2 ramp exercise tests on a cycle ergometer. Systemic FTs were calculated from gas exchange and ventilation variables. Localized FTs were calculated from electromyography and...
Article
Full-text available
Resistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 res...
Data
Data. Note: 30 = 30% of longitudinal distance [Distal]; 50 = 50% of longitudinal distance [Middle]; 70 = 70% of longitudinal distance [Proximal]; CSA = Cross-sectional area; MT = Muscle thickness; PRE = Pre-training; POST = Post-training; RF = Rectus femoris; VL = Vastus lateralis. (XLSX)
Article
The majority of barefoot running studies have not considered speed as an influential factor on foot strike pattern. The aim of this study was to investigate differences in foot strike pattern and spatiotemporal characteristics between barefoot and shod overground running at varying speeds. We first determined maximal running speed (Vm) over 50 m in...
Article
Full-text available
Purpose: To examine the impact of polyphenol supplementation on the recruitment, mobilization and activation of monocyte subsets following resistance exercise. Methods: Thirty-eight recreationally active males (22.1 ± 3.1 yrs; 173.9 ± 7.9 cm; 77.8 ± 14.5 kg) were assigned to 28-days of polyphenol supplementation (PPB), placebo (PL) or control (C...
Preprint
Full-text available
Resistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 res...
Article
Full-text available
The influence of baseline strength or muscle size on adaptations to training is not well-understood. Comparisons between novice and advanced lifters, and between stronger and weaker experienced-lifters, have produced conflicting results. This study examined the effect of baseline muscle strength and size on subsequent adaptations in resistance-trai...
Article
Full-text available
The purpose of this study was to examine the effects of 28-days of supplemen-tation with an aqueous proprietary polyphenol blend (PPB) sourced from Camellia sinensis on intramuscular apoptotic signaling following an acute lower-body resistance exercise protocol and subsequent recovery. Untrained males (n = 38, 21.8 2.7 years, 173.4 7.9 cm, 77.6 14....
Chapter
Full-text available
β-Alanine is one of the more popular sport supplements used by strength/power athletes today. The popularity of β-alanine stems from its ability to enhance intracellular muscle-buffering capacity thereby delaying fatigue during high-intensity exercise by increasing muscle carnosine content. Recent evidence also suggests that elevated carnosine leve...
Article
Full-text available
Introduction. The purpose of this study was to examine the effects of a 10-week introductory Judo class on force-time characteristics during an explosive isometric gripping task. Material and methods. Twenty-two healthy men and women (age: 21.8±3.2yr; height: 169.6±7.4cm; body mass: 75.4±13.2 kg), 10 in an introductory judo class and 12 age-matched...
Article
Purpose: To evaluate the effects of moderate normobaric hypoxia on the parameters of the work-time relationship in the upper body. Methods: Twenty-one recreationally active men completed a graded exercise test in both normobaric hypoxia (H) and normoxia (N) to exhaustion on an arm ergometer to determine V̇O2peak and peak power output (PPO). Each...
Article
Full-text available
Background Intramyocellular triacylglycerol (IMTG) is utilized as metabolic fuel during exercise and is linked to insulin resistance, but the long-term effect of weight loss strategies on IMTG among participants with abdominal fat, remain unclear. Methods In an 18-month trial, sedentary participants with abdominal fat/dyslipidemia were randomized...