Eric T Trexler

University of North Carolina at Chapel Hill | UNC · Department of Exercise and Sport Science

This study evaluated the influence of acute water ingestion and maintaining an upright posture on raw bioimpedance and subsequent estimates of body fluids and composition. Twenty healthy adults participated in a randomized crossover study. In both conditions, an overnight food and fluid fast was followed by an initial multi-frequency bioimpedance a...

Lewis, MH, Siedler, MR, Lamadrid, P, Ford, S, Smith, T, SanFilippo, G, Waddell, B, Trexler, ET, Buckner, S, and Campbell, BI. Sex differences may exist for performance fatigue but not recovery after single-joint upper-body and lower-body resistance exercise. J Strength Cond Res XX(X): 000-000, 2022-This study evaluated sex differences in performanc...

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...

An amendment to this paper has been published and can be accessed via the original article.

Background & aims It is recommended that patients consume at least 60 g of dietary protein per day to attenuate loss of fat-free mass (FFM) following bariatric surgery. To date, research on the effectiveness and tolerability of protein supplementation in bariatric patients is limited. The purpose of the current study was to determine if provision o...

We carried out a prospective case study in a high-level amateur natural male bodybuilder throughout preparation for 4 competitions and during the ensuing post-contest recovery period. Laboratory testing was conducted monthly over a 1-year period, which included the following assessments: B-mode ultrasound evaluation of muscle thickness (MT), multi-...

The purpose of the present study was to examine the acute effects of an herbal supplement containing a 70:30 blend of Rhaponticum carthamoides extract and Rhodiola rosea extract, respectively, on performance fatigability and the affective responses prior to and following exercise. Thirty men (age = 22.3 ± 4.1 years) volunteered for this randomized,...

The purpose of this case-series was to evaluate the physiological, psychological and performance-related changes that occur during the postcompetition period. Participants included three male (34.3 ± 6.8 years, 181.6 ± 8.9 cm) and four female (29.3 ± 4.9 years, 161.4 ± 6.0 cm) natural physique athletes. Body composition (fat mass (FM) and fat-free...

The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and f...

The ergogenic effects of citrulline malate (CitMal) and beetroot juice (BEET) have been widely studied, but their effects on physiological outcomes related to resistance exercise are not fully understood. The purpose of this randomized, double-blind, crossover study was to investigate the effects of CitMal (8 g) and BEET (400 mg nitrate) on blood p...

Objectives: To create normative data for visceral adipose tissue (VAT) derived from the GE Lunar iDXA specific to sex and age cohorts for adults in the United States (US). Methods: A cross-sectional analysis of 649 adults were evaluated (Mean ± SD [Range]: Males: n=351; Age=33·2 ± 17·4y [18-75y]; Body mass index [BMI]=26·5 ± 5·4 kg·m-2 [17·5-44·...

Trexler, ET, Keith, DS, Schwartz, TA, Ryan, ED, Stoner, L, Persky, AM, and Smith-Ryan, AE. Effects of citrulline malate and beetroot juice supplementation on blood flow, energy metabolism, and performance during maximum effort leg extension exercise. J Strength Cond Res XX(X): 000-000, 2019-Citrulline malate (CitMal) and beetroot juice (BEET) are i...

Background Citrulline is an increasingly common dietary supplement that is thought to enhance exercise performance by increasing nitric oxide production. In the last 5 years, several studies have investigated the effects of citrulline supplements on strength and power outcomes, with mixed results reported. To date, the current authors are unaware o...

The purpose of this paper was to determine the effect of replacing breakfast with a high-fat drink on fat mass (FM), lean mass (LM), percent body fat (%BF), visceral fat (VAT), resting metabolic rate (RMR), fuel utilization (RER), blood lipids and satiety in overweight and obese adults. Healthy adults (n = 42; 21 Females; body mass index (BMI): 32....

The purpose of this study was to establish normative fat-free mass index (FFMI) ranges in collegiate female athletes. A sample of 266 female athletes (Mean±SD; Age: 19.7 ± 1.5 yrs, Height: 166.0 ± 6.4 cm, Weight: 63.2 ± 8.8 kg) were included in analyses. Dual-energy X-ray absorptiometry measured bone mineral content (BMC; kg) and lean mass (LM; kg)...

This study sought to investigate the effects of a multistrain probiotic on body composition, regional adiposity, and a series of associated metabolic health outcomes. Female health care workers employed on a rotating-shift schedule (n = 41) completed baseline anthropometric assessments; a fasted blood draw; questionnaires to assess anxiety, depress...

Increased blood flow via vasodilation, metabolite production, and venous pooling contribute to the hyperaemia and cellular swelling experienced during resistance training. These effects have been suggested to play a role in hypertrophic adaptations. Over the past two decades sport supplement products have been marketed to promote exercise hyperaemi...

Objectives The purpose of this study was to determine the effects of pre- vs. post-workout nutrition on strength, body composition, and metabolism in trained females over 6 weeks of high intensity resistance training (HIRT). Design Forty-three trained females (Mean ± SD; Age: 20.5 ± 2.2 yrs; Height: 165.2 ± 5.7 cm; Body Mass: 66.5 ± 11.4 kg) were...

There is a typo in the original equation describing lean mass, and it has also been pointed out to the authors that the model is not strictly energy balanced.

Background: Obesity has frequently been associated with higher amounts of extracellular fluid (ECF) stores in the body when compared to normal weight individuals. Elevated ECF is associated with conditions such as edema, hypertension, and congestive heart failure. Individuals are classified as normal weight obese (NWO) if they have a normal body ma...

Tinsley, GM, Trexler, ET, Smith-Ryan, AE, Paoli, A, Graybeal, AJ, Campbell, BI, and Schoenfeld, BJ. Changes in body composition and neuromuscular performance through preparation, two competitions, and a recovery period in an experienced female physique athlete. J Strength Cond Res XX(X): 000-000, 2018-This prospective case study evaluated an experi...

Background: Body composition (%BF), omega-3 and vitamin D (VitD) status are important components of an athlete's individual physiological profile, as each measure has potential to influence performance, inflammation, and injury recovery. The purpose of this study was to characterize %BF, omega-3, and VitD in a subset of professional football athle...

Background Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power. Methods A search through eight...

The purpose of the present study was to assess the validity of dual-energy X-ray absorptiometry (DXA) to estimate body volume (BV) for use in a four-compartment (4C) body composition model in an overweight/obese population. Body composition of 61 overweight/obese adults (Age: 37.3 ± 10.0 yrs; Height: 170.2 ± 9.5 cm; Body mass: 97.1 ± 17.4 kg) was m...

Purpose: Current diet and exercise methods used to maintain or improve body composition often have poor long-term outcomes. We hypothesize that resistance exercise (RE) should aid in the maintenance of a healthy body composition by preserving lean mass (LM) and metabolic rate. Method: We extended a previously developed energy balance model of hu...

The current study sought to evaluate the effects of post-exercise ingestion of a high molecular weight glucose polymer solution (HMW) compared to an isocaloric low molecular weight solution (LMW) or placebo (PLA) on subsequent cycling performance in female athletes. In a randomized, double-blind, placebo-controlled, cross-over design, 10 competitiv...

Purpose: Elevated rates of cardiometabolic diseases have been observed in former American football players. The current study sought to determine if change in body mass index (ΔBMI) following retirement influences the prevalence of coronary heart disease (CHD), diabetes, or high blood pressure (HBP) in former professional football players. Method...

Extreme body composition demands of competitive bodybuilding have been associated with unfavorable physiological changes, including alterations in metabolic rate and endocrine profile. The current case study evaluated the effects of contest preparation (8 months), followed by recovery (5 months), on a competitive drug-free male bodybuilder over 13...

Caffeine is the mostly widely consumed psychoactive drug in the world. Its ingestion (3-9. mg/kg body weight) prior to exercise seems to increases performance during prolonged endurance exercise. The effects of acute caffeine ingestion on strength and power performance are equivocal, but some studies demonstrated positive effects in well-trained at...

BACKGROUND: Body composition has important implications for both athletic performance and injury risk. Data from various athletic populations have shown that body composition remains relatively constant for the duration of the competitive season. However, pronounced training adaptations may be anticipated in freshmen athletes who have not been expo...

BACKGROUND: While the ideal macronutrient composition of an individual’s diet is highly debated, data have indicated that high protein (PRO) intake may favorably influence body composition and blood lipid profile. This may be particularly beneficial to shift-workers who have reported higher adiposity. The primary purpose of this study was to evalua...

Objectives Despite growing popularity of high intensity interval training (HIIT) for improving health and fitness, limited data exist identifying the effects of HIIT on muscle characteristics. The purpose of the current study was to investigate the effects of a 3-week HIIT intervention on muscle size and quality in overweight and obese men and wome...

The purpose of the current study was to evaluate changes in body composition, metabolic rate, and hormones during post-competition recovery. Data were collected from natural physique athletes (7 male/8 female) within one week before (T1) competition, within one week after (T2), and 4-6 weeks after (T3) competition. Measures included body compositio...

Brown adipose tissue (BAT) in adults has been shown to have a meaningful impact on energy expenditure and cold-induced thermogenesis. Data from rodent research have suggested that exercise may be a promising method of increasing BAT activity, with potential applications to the treatment and prevention of obesity and diabetes. However, emerging huma...

PURPOSE: To evaluate and characterize body composition changes that occur longitudinally over multiple seasons of collegiate cross country running. METHODS: Thirty-five NCAA division I cross country runners (16 females and 19 males; Mean ± SD; Age: 20.6 ± 1.1 yrs; Height: 173.0 ± 8.3 cm; Weight: 61.2 ± 8.0 kg) were included in the study. Dual-energ...

PurposeLow resting metabolic rate (RMR) and high carbohydrate reliance at rest are associated with weight gain, but are highly variable in obese individuals. This study determined the relationship of total and segmental body composition and adiposity hormones with RMR and respiratory exchange ratio (RER) in overweight and obese adults. Methods In 4...

Measurement of body composition to assess health risk and prevention is expanding. Accurate portable techniques are needed to facilitate use in clinical settings. This study evaluated the accuracy and repeatability of a portable ultrasound (US) in comparison with a four-compartment criterion for per cent body fat (%Fat) in overweight/obese adults....

Context: Previous researchers have indicated the importance of body composition and muscle quality in athletic performance. However, body composition and muscle-quality measures in swimmers and divers over a training season have yet to be evaluated. Objective: To identify changes in body composition and muscle characteristics over a competitive...

Fat-free mass index (FFMI) is a height-adjusted assessment of fat-free mass, with previous research suggesting a natural upper limit of 25 kg[BULLET OPERATOR]m in resistance-trained males. The current study evaluated upper limits for FFMI in collegiate American football players (n=235), and evaluated differences between positions, divisions, and ag...

Objectives: Traditional evaluations of metabolic health may overlook underlying dysfunction in individuals who show no signs of insulin resistance or dyslipidemia. The purpose of this study was to characterize metabolic health in overweight and obese adults using traditional and non-traditional cardiometabolic variables. A secondary purpose was to...

The effects of pomegranate extract (PE) supplementation were evaluated on high-intensity exercise performance, blood flow, vessel diameter, oxygen saturation (SPO2), heart rate (HR), and blood pressure (BP). In a randomized, crossover design, nineteen recreationally resistance-trained participants were randomly assigned to PE (1000 mg) or placebo (...

Effects of MusclePharm Assault BlackTM on lower extremity spinal excitability and postactivation potentiation: A pilot study Brian Wallace*, Haley Bergstrom, Kelly Wallace Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA Email: brian.wallace@uky.edu; brian.wallace@northern.edu Background: Caffeine h...

To determine the effects of a mushroom blend containing Cordyceps militaris on high-intensity exercise after 1 and 3 weeks of supplementation. Twenty-eight individuals (Mean ± standard deviation [SD]; Age = 22.7 ± 4.1 yrs; Height = 175.4 ± 8.7 cm; Weight = 71.6 ± 12.0 kg) participated in this randomized, repeated measures, double-blind, placebo-con...

Background: Body volume (BV), one component of a four-compartment (4C) body composition model, is commonly assessed using air displacement plethysmography (BodPod). However, dual-energy x-ray absorptiometry (DEXA) has been proposed as an alternative method for calculating BV. Aims: This investigation evaluated the validity and reliability of DEX...

Trexler, ET, Smith-Ryan, AE, Mann, JB, Ivey, PA, Hirsch, KR, and Mock, MG. Longitudinal body composition changes in NCAA Division I college football players. J Strength Cond Res 31(1): 1–8, 2017—Many athletes seek to optimize body composition to fit the physical demands of their sport. American football requires a unique combination of size, speed,...

Background: Metabolic flexibility is the ability to alter substrate utilization in response to substrate availability, which may influence health and performance. The current study evaluated the effects of habitual macronutrient distribution on energy expenditure (EE) and metabolic flexibility in physically active women. Methods: Participants (n...

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg · m2) were randomly assigned to ten 1-min high-intensity intervals (90%VO2 peak, 1 min recovery) or five 2-min hi...

The purpose of this study was to examine the effect of exercise modality and pre-exercise carbohydrate (CHO) or protein (PRO) ingestion on post-exercise resting energy expenditure (REE) and respiratory exchange ratio (RER) in women. Twenty recreationally active women (mean ± SD; age 24.6 ± 3.9 years; height 164.4 ± 6.6 cm; weight 62.7 ± 6.6 kg) par...

The purpose of this study was to determine the effect of 5 d of creatine (CRE) loading alone or in combination with caffeine anhydrous (CAF) or coffee (COF) on upper and lower body strength and sprint performance. Physically active males (n=54; Mean ± SD; Age = 20.1 ± 2.1 yrs; Weight = 78.8 ± 8.8 kg) completed baseline testing, consisting of one-re...

Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions...

Research has demonstrated an elevated prevalence of body weight concerns and scoliosis among female gymnasts. The purpose of the current pilot study was to evaluate the utility of ultrasonography and dual-energy X-ray absorptiometry (DXA) as practical imaging modalities to measure body composition and spinal curvature variables that may correlate w...

The purpose of this study was to evaluate event-specific body composition and muscle characteristics of track and field athletes, and to assess body composition changes after one year. Sixty collegiate track and field athletes (Mean +/- SD; Age = 19.2 +/- 1.4 yrs, Height = 174.6 +/- 9.0 cm, Weight = 71.5 +/- 12.5 kg) were stratified into six event...

Nutritional supplementation is a common practice among athletes, with creatine and caffeine among the most commonly used ergogenic aids. Hundreds of studies have investigated the ergogenic potential of creatine supplementation, with consistent improvements in strength and power reported for exercise bouts of short duration (≤30 seconds) and high in...

Position statement The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of beta-alanine supplementation. Based on the current available literature, the conclusions of the ISSN are as follows: 1) Four weeks of beta-alanine supplementation (4–6 g daily) significantly augments muscle...

During exercise, the demand for oxygen and energy substrates is elevated in active skeletal muscle. Supplements with high nitrate and polyphenol content have been shown to increase nitric oxide production and enhance exercise efficiency. The current randomized, double-blind, placebo-controlled, crossover study aimed to investigate the acute effects...

Few studies exist evaluating metabolic responses to exercise and nutrition in women. Understanding sex-specific fuel differences may improve exercise prescription. PURPOSE: To examine the effect of exercise modality and pre-exercise carbohydrate (CHO) or protein (PRO) ingestion on respiratory exchange ratio (RER) in women. Methods Twenty recreation...

Previous research has demonstrated that habitual dietary macronutrient distribution affects energy substrate utilization at rest and during exercise. The primary purpose of the current study was to examine the relationships between habitual baseline macronutrient intakes, expressed relative to bodyweight and percentage of total energy intake, and m...

The primary purpose was to identify the relationship between muscle cross sectional area (mCSA), echo intensity (EI), and body composition of Division I cross-country runners. The secondary purpose was to examine differences in these variables in athletes stratified based on stress fracture (SFx) history. Thirty-six athletes were stratified based o...

The purpose of the current study was to examine muscle characteristics of the vastus lateralis (VL) and body composition of NCAA Division I football players. Sixty-nine Division I football players (Mean±SD; Age: 20.0±1.1 yrs; Height: 186.2±7.0 cm; Body mass: 106.3±21.1 kg; %fat: 17.8±4.6 %) were stratified by player position, race, year and starter...

Recent research has shown that dietary nitrate has favorable effects on blood flow and exercise performance. The purpose of this randomized, double-blind, placebo-controlled crossover study was to investigate the acute effects of pomegranate extract on blood flow, vessel diameter, and exercise performance in active individuals. Nineteen men and wom...