Cody Taylor Haun

Dr. Haun's Fitness Lab

Recent evidence suggests that resistance training with light or heavy loads to failure results in similar adaptations. Herein, we compared how both training modalities affect the molecular, neuromuscular, and recovery responses following exercise. Resistance-trained males (mean AE SE: 22 AE 2 years, 84.8 AE 9.0 kg, 1.79 AE 0.06 m; n = 15) performed...

Background . We sought to examine how 12 weeks of resistance exercise training (RET) affected skeletal muscle myofibrillar and sarcoplasmic protein levels along with markers of mitochondrial physiology in high versus low anabolic responders. Methods . Untrained college-aged males were classified as anabolic responders in the top 25 th percentile [H...

Numerous reports suggest there are low and high skeletal muscle hypertrophic responders following weeks to months of structured resistance exercise training (referred to as low and high responders herein). Specifically, divergent alterations in muscle fiber cross sectional area (fCSA), vastus lateralis thickness, and whole body lean tissue mass hav...

We examined hypertrophic outcomes of weekly graded whey protein dosing (GWP) vs. whey protein (WP) or maltodextrin (MALTO) dosed once daily during 6 weeks of high-volume resistance training (RT). College-aged resistance-trained males (training age = 5 ± 3 years; mean ± SD) performed 6 weeks of RT wherein frequency was 3 d/week and each session invo...

Skeletal muscle is highly adaptable and has consistently been shown to morphologically respond to exercise training. Skeletal muscle growth during periods of resistance training has traditionally been referred to as skeletal muscle hypertrophy, and this manifests as increases in muscle mass, muscle thickness, muscle area, muscle volume, and muscle...

The purpose of this study was to examine the effects of different rest interval lengths (RIL) on repetition performance, rating of discomfort and blood lactate responses during lower body single-joint and multi-joint exercises. This study employed a counterbalanced design where each subject performed the Smith machine back squat (BS) and leg extens...

The present review aims to explore and discuss recent research relating to the lactate response to resistance training and the potential mechanisms by which lactate may contribute to skeletal muscle hypertrophy or help to prevent muscle atrophy. First, we will discuss foundational information pertaining to lactate including metabolism, measurement,...

This study assesses if a lower dose of whey protein can provide similar benefits to those shown in previous work supplementing Army Initial Entry Training (IET) Soldiers with two servings of whey protein (WP) per day. Eighty-one soldiers consumed one WP or a calorie matched carbohydrate (CHO) serving/day during IET (WP: n = 39, height = 173 ± 8 cm,...

We evaluated the effects of higher-load (HL) versus (lower-load) higher-volume (HV) resistance training on skeletal muscle hypertrophy, strength, and muscle-level molecular adaptations. Trained men (n = 15, age: 23 ± 3 years; training experience: 7 ± 3 years) performed unilateral lower-body training for 6 weeks (3× weekly), where single legs were r...

Human muscle fibers are generally classified by myosin heavy chain (MHC) isoforms characterized by slow to fast contractile speeds. Type I, or slow-twitch fibers, are seen in high abundance in elite endurance athletes, such as long-distance runners and cyclists. Alternatively, fast-twitch IIa and IIx fibers are abundant in elite power athletes, suc...

Hypertrophy can be operationally defined as an increase in the axial cross-sectional area of a muscle fiber or whole muscle, and is due to increases in the size of pre-existing muscle fibers. Hypertrophy is a desired outcome in many sports. For some athletes, muscular bulk and, conceivably, the accompanying increase in strength/power, are desirable...

Aim We evaluated the effects of higher-load (HL) versus (lower-load) higher-volume (HV) resistance training on skeletal muscle hypertrophy, strength, and muscle-level molecular markers. Methods Trained men (n=15, age: 23±3 y; training experience: 7±3 y) performed unilateral lower body training for 6 weeks (3x weekly), where single legs were assign...

Vann, CG, Haun, CT, Osburn, SC, Romero, MA, Roberson, PA, Mumford, PW, Mobley, CB, Holmes, HM, Fox, CD, Young, KC, and Roberts, MD. Molecular differences in skeletal muscle after 1 week of active vs. passive recovery from high-volume resistance training. J Strength Cond Res 35(8): 2102-2113, 2021-Numerous studies have evaluated how deloading after...

We examined the association between genotype and resistance training‐induced changes (12 wk) in dual x‐ray energy absorptiometry (DXA)‐derived lean soft tissue mass (LSTM) as well as muscle fiber cross‐sectional area (fCSA; vastus lateralis; n = 109; age = 22 ± 2 y, BMI = 24.7 ± 3.1 kg/m2). Over 315 000 genetic polymorphisms were interrogated from...

Introduction: Amino acid transporters are essential for cellular amino acid transport and promoting protein synthesis. While previous literature has demonstrated the association of amino acid transporters and protein synthesis following acute resistance exercise and amino acid supplementation, the chronic effect of resistance exercise and supplemen...

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-...

We read the article of Buckner et al. (1), hoping to find new insights on resistance training. Unfortunately, the article is a restatement of information contained in previously published reviews from this group. Here are our major concerns: HYPERTROPHY AND STRENGTH GAINS Buckner et al. believe that high-volume phases are unnecessary. Initial alter...

Training civilians to be soldiers is a challenging task often resulting in musculoskeletal injuries, especially bone stress injuries. This study evaluated bone health biomarkers (P1NP/CTX) and whey protein or carbohydrate supplementations before and after Army initial entry training (IET). Ninety male IET soldiers participated in this placebo-contr...

Skeletal muscle fibers are multinucleated cells that contain mostly myofibrils suspended in an aqueous media termed the sarcoplasm. Select evidence suggests sarcoplasmic hypertrophy, or a disproportionate expansion of the sarcoplasm relative to myofibril protein accretion, coincides with muscle fiber or tissue growth during resistance training. The...

It has been proposed that superior muscle hypertrophy may be obtained by training muscles predominant in type I fibers with lighter loads and those predominant in type II fibers with heavier loads. Purpose: To evaluate longitudinal changes in muscle strength and hypertrophy of the soleus (a predominantly slow-twitch muscle) and gastrocnemius (muscl...

Several published protocols exist for isolating contractile or myofibrillar (MF) proteins from skeletal muscle, however, achieving complete resuspension of the myofibril pellet can be technically challenging. We performed several previously published MF isolation methods with the intent of determining which method was most suitable for MF protein i...

We aimed to investigate the effects of resistance training (RT) combined with no-load isometric actions (iso-holds) during the inter-set recovery period versus RT that involves passive inter-set rest on muscular strength, muscular hypertrophy, and muscular endurance in resistance-trained men. Twenty-seven resistance-trained male volunteers were ran...

Resistance training generally increases skeletal muscle hypertrophy, whereas aging is associated with a loss in muscle mass. Interestingly, select studies suggest that aging, as well as resistance training, may lead to a reduction in the abundance of skeletal muscle myofibrillar (or contractile) protein (per mg tissue). Proteomic interrogations hav...

We examined molecular mechanisms that were altered during rapid soleus (type I fiber-dominant) and plantaris (type II fiber-dominant) hypertrophy in rats. Twelve Wistar rats (3.5 months old; 6 female, 6 male) were subjected to surgical right-leg soleus and plantaris dual-overload (SA), and sham surgeries were performed on left legs (CTL). Fourteen...

Resistance training volume, determined by the number of sets performed (set-volume) is considered one of the key variables in promoting muscle hypertrophy. To better guide resistance exercise prescription for weekly per-muscle training volume, the purpose of this paper is to provide evidence-based considerations for set-volume ratios between multi-...

Cellular adaptations that occur during skeletal muscle hypertrophy in response to high-volume resistance training are not well-characterized. Therefore, we sought to explore how actin, myosin, sarcoplasmic protein, mitochondrial, and glycogen concentrations were altered in individuals that exhibited mean skeletal muscle fiber cross-sectional area (...

The current study investigated how bovine milk extracellular vesicles (EVs) affected rotarod performance and biomarkers of skeletal muscle physiology in young, growing rats. Twenty-eight-day Fisher 344 rats were provided an AIN-93G-based diet for 4 weeks that either remained unadulterated [EVs and RNA-sufficient (ERS; n = 12)] or was sonicated [EVs...

Cellular adaptations that occur during skeletal muscle hypertrophy in response to high-volume resistance training are not well-characterized. Therefore, we sought to explore how actin, myosin, sarcoplasmic protein, mitochondrial, and glycogen concentrations were altered in individuals that exhibited mean skeletal muscle fiber cross-sectional area (...

Raw data from this study.

Limited evidence exists regarding differentially expressed biomarkers between previously-trained low versus high hypertrophic responders in response to resistance training. Herein, 30 college-aged males (training age 5 ± 3 years; mean ± SD) partook in 6 weeks of high-volume resistance training. Body composition, right leg vastus lateralis (VL) biop...

The primary means for disseminating sport and exercise science research is currently through journal articles. However, not all studies, especially those with null findings, make it to formal publication. This publication bias towards positive findings may contribute to questionable research practices. Preregistration is a solution to prevent the pub...

Purpose Betalains are indole-derived pigments found in beet root, and recent studies suggest that they may exert ergogenic effects. Herein, we examined if supplementation for 7 days with betalain-rich beetroot concentrate (BLN) improved cycling performance or altered hemodynamic and serum analytes prior to, during and following a cycling time trial...

Introduction: Protein supplementation is proposed to promote recovery and adaptation following endurance exercise. While prior literature demonstrates improved performance when supplementing protein during or following endurance exercise, chronic supplementation research is limited. Methods: Runners (VO2peak = 53.6 ± 8.9 ml/kg/min) were counter-bal...

Training volume for each participant throughout the study.

Daily training volume for each participant throughout the study.

Blood cell differential data.

haun_supplementary_data.csv—this file includes all raw data.

haun_supplementary_tables.pdf—this file includes descriptive tables for each dependent variable.

Vastus lateralis thickness (ultrasound).

Biceps brachii thickness (ultrasound).

Extracellular water (BIS).

Intracellular water (BIS).

Pressure to pain threshold (Algometry).

Fiber count and fiber cross sectional area.

haun_supplementary_diet.csv—this file includes dietary recommendations as well as self-reported dietary intakes.

Total body fat mass (DXA).

Pre-study body composition and strength descriptive measurements.

Training volume load and repetitions in reserve.

Total lean body mass (DXA).

Total mood disturbance scores (POMS Questionnaire).

We investigated the effects of whey protein (WP) supplementation on body composition and physical performance in soldiers participating in Army Initial Entry Training (IET). Sixty-nine, male United States Army soldiers volunteered for supplementation with either twice daily whey protein (WP, 77 g/day protein, ~580 kcal/day; n = 34, age = 19 ± 1 yea...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Background We sought to examine how 12 weeks of resistance exercise training (RET) affected skeletal muscle myofibrillar and sarcoplasmic protein levels along with markers of mitochondrial physiology in high versus low anabolic responders. Methods Untrained college-aged males were classified as anabolic responders in the top 25th percentile (high-...

Raw data. Raw data in EXL format ready to be entered into data processing software (e.g., SPSS).

Raw Coomassie and Western blot images.

It is currently unclear as to whether sex hormones are significantly affected by soy or whey protein consumption. Additionally, estrogenic signaling may be potentiated via soy protein supplementation due to the presence of phytoestrogenic isoflavones. Limited also evidence suggests that whey protein supplementation may increase androgenic signaling...

Background . We sought to examine how 12 weeks of resistance exercise training (RET) affected skeletal muscle myofibrillar and sarcoplasmic protein levels along with markers of mitochondrial physiology in high versus low anabolic responders. Methods . Untrained college-aged males were classified as anabolic responders in the top 25 th percentile [H...

We sought to determine whether age-related gastrocnemius muscle mass loss was associated with parallel decrements in androgen receptor (AR) or select Wnt signaling markers. To test this hypothesis, serum-free and total testosterone (TEST) and gastrocnemius AR and Wnt signaling markers were analyzed in male Fischer 344 rats that were 3, 6, 12, 18, a...

Endurance (END)- and resistance (RES)-trained males performed interval running or resistance exercise during three consecutive days (bouts 1–3). Muscle biopsies were obtained at baseline, 2 h post-bout 1, and 72 h post-bout 3. Amino acid transporter SNAT2 mRNA was 75% greater in END (group p = 0.008), and increased ~ 70% 2 h post in both groups (ti...

We sought to identify biomarkers which delineated individual hypertrophic responses to resistance training. Untrained, college-aged males engaged in full-body resistance training (3 d/wk) for 12 weeks. Body composition via dual x-ray absorptiometry (DXA), vastus lateralis (VL) thickness via ultrasound, blood, VL muscle biopsies, and three-repetitio...

Analytical methods. (DOCX)