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Male military personnel conducting strenuous operations experience reduced testosterone concentrations, muscle mass, and physical performance. Pharmacological restoration of normal testosterone concentrations may attenuate performance decrements by mitigating muscle mass loss. Previously, administering testosterone enanthate (200 mg/wk) during 28 days of energy deficit prompted supraphysiological testosterone concentrations and lean mass gain without preventing isokinetic/isometric deterioration. Whether administering a practical dose of testosterone protects muscle and performance during strenuous operations is undetermined. The objective of this study was to test the effects of a single dose of testosterone undecanoate on body composition and military-relevant physical performance during a simulated operation. After a 7-day baseline phase (

BackgroundRecent three-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise with respect to clinical measures made by dual-energy X-ray absorptiometry (DXA). However, the sensitivity for monitoring body composition change over time with 3DO body shape is unknown.ObjectiveTo evaluate 3DO’s ability to monitor body composition changes across multiple intervention studies.MethodsA retrospective analysis was performed using intervention studies on healthy adults that were complimentary to the cross-sectional study, Shape Up! Adults. Each participant received a DXA (Hologic Discovery/A system) and 3DO (Fit3D ProScanner) scan at baseline and follow-up. 3DO meshes were digitally registered and reposed using Meshcapade to standardize the vertices and pose. Using an established statistical shape model, each 3DO mesh was transformed into principal components (PCs), which were used to predict whole-body and regional body composition values using published equations. Body composition changes (follow-up minus baseline) were compared to DXA with linear regression.ResultsThe analysis included 133 participants (45 females) in six studies. The mean (SD) length of follow-up was 13 (5) weeks, range 3-23 weeks. Agreement between 3DO and DXA (R2) for changes in total fat mass (FM), total fat-free mass (FFM), and appendicular lean mass, respectively, were 0.86, 0.73, and 0.70 with RMSEs of 1.98 kg, 1.58 kg, and 0.37 kg in females, and 0.75, 0.75, and 0.52 with RMSEs of 2.31 kg, 1.77 kg, and 0.52 kg in males. Further adjustment with demographic descriptors improved the 3DO change agreement to changes observed with DXA.ConclusionsAs compared to DXA, 3DO was highly sensitive in detecting body shape changes over time. The 3DO method was sensitive enough to detect even small changes in body composition during intervention studies. The safety and accessibility of 3DO allows users to self-monitor on a frequent basis throughout interventions.

BACKGROUND Effects of high protein (HP) diets and prolonged energy restriction (ER) on integrated muscle protein kinetics have not been determined. OBJECTIVE The objective of this study was to measure protein kinetics in response to prolonged ER and HP on muscle protein synthesis (MPS; absolute rates of synthesis) and muscle protein breakdown (MPB; half-lives) for proteins across the muscle proteome. METHODS Female 6-wk-old obese Zucker rats (Leprfa+/fa+, n = 48) were randomly assigned to one of four diets for 10 wk: ad libitum-standard protein (AL-SP; 15% kcal from protein), AL-HP (35% kcal from protein), ER-SP, and ER-HP (both fed 60% feed consumed by AL-SP). During week 10, heavy/deuterated water (2H2O) was administered by intraperitoneal injection, and isotopic steady-state was maintained via 2H2O in drinking water. Rats were euthanized after 1 wk, and mixed-MPS as well as fractional replacement rate (FRR), relative concentrations, and half-lives of individual muscle proteins were quantified in the gastrocnemius. Data were analyzed using 2-factor (energy × protein) ANOVAs and 2-tailed t-tests or binomial tests as appropriate. RESULTS Absolute MPS was lower in ER than AL for mixed-MPS (-29.6%; P < 0.001) and MPS of most proteins measured [23/26 myofibrillar, 48/60 cytoplasmic, and 46/60 mitochondrial (P < 0.05)], corresponding with lower gastrocnemius mass in ER compared with AL (-29.4%; P < 0.001). Although mixed-muscle protein half-life was not different between groups, prolonged half-lives were observed for most individual proteins in HP compared with SP in ER and AL (P < 0.001), corresponding with greater gastrocnemius mass in HP than SP (+5.3%; P = 0.043). CONCLUSIONS ER decreased absolute bulk MPS and most individual MPS rates compared with AL, and HP prolonged half-lives of most proteins across the proteome. These data suggest that HP, independent of energy intake, may reduce MPB, and reductions in MPS may contribute to lower gastrocnemius mass during ER by reducing protein deposition in obese female Zucker rats.

The French chemist Michel Eugène Chevreul discovered creatine in meat two centuries ago. Extensive biochemical and physiological studies of this organic molecule followed with confirmation that creatine is found within the cytoplasm and mitochondria of human skeletal muscles. Two groups of investigators exploited these relationships five decades ago by first estimating the creatine pool size in vivo with

Objective: Recumbent rest elicits a decrease in muscle size of the lower extremity, but the extent of decrease may be related to differences in muscle quality. This could have implications for ultrasound-derived measures of muscle size, particularly in individuals with a large proportion of intramuscular contractile elements. The research objective was to determine whether decreases in muscle size following recumbent rest are related to ultrasound-derived corrected echo intensity in resistance-trained males. Methods: Cross-sectional area (CSA), echo intensity (EI), subcutaneous fat thickness (SFT), and EI corrected for SFT (EICor) of the vastus lateralis (VL) were measured via ultrasonography in 30 resistance-trained males. Measures were obtained immediately following recumbency (T0) and 15 minutes after recumbency (T15). The association between EICor and percentage change in CSA (%ΔCSA) from T0 to T15 was examined. Comparisons of morphological characteristics were examined between a subset of participants with the lowest (LO; n = 10; 66th percentile) EICor. Results: EICor was not correlated with %ΔCSA ( P = .151), and the decrease in CSA from T0 to T15 did not differ between the LO and HI groups. Conclusions: Muscle quality (EICor) is not related to the decrease in CSA of the VL following recumbent rest among resistance-trained, young males. The time frame of muscle CSA acquisition should not differ based solely on differences in muscle quality.

Background Ultrasonography is used to evaluate muscle quality (i.e. echo intensity [EI]), but an attenuation of ultrasound waves occurs in deeper tissues, potentially affecting these measures. Purpose To determine whether muscle thickness (MT) affects EI and if EI varies between the superficial and deep portions of the muscle. Materials and Methods MT, EI, subcutaneous adipose tissue thickness (SAT), tissue depth (DISDEEP), and EI of the overall (EIFULL) as well as deep (EIDEEP) and superficial (EISUPF) portions of the vastus lateralis (VL) were assessed in 33 resistance-trained males using ultrasonography. The difference (EIDIFF) between EISUPF and EIDEEP was calculated. Mean differences between EIFULL, EISUPF, and EIDEEP were analyzed using a repeated-measures analysis of variance (ANOVA). Relationships between measures of muscle depth/ thickness and EI were examined using Pearson’s r. Results EISUPF was greater than EIDEEP ( P FULL ( P FULL ( P DIFF ( P DEEP was positively correlated with EIDIFF ( P Conclusion EI of the VL is heterogeneous, as the deeper portion produces lower values than the superficial portion. Thicker muscles present lower EI but have greater discrepancies in EI between the superficial and deep portions. Although SAT was not correlated with EI, DISDEEP was related to EIDIFF, demonstrating that the combination of MT and SAT should be considered when evaluating muscle quality. Future research is necessary to determine if changes in EI following resistance training are driven by increases in MT.

Physical and psychological stress alter gut-brain axis activity, potentially causing intestinal barrier dysfunction that may, in turn, induce cognitive and mood impairments through exacerbated inflammation and blood brain barrier (BBB) permeability. These interactions are commonly studied in animals or artificial laboratory environments. However, military survival training provides an alternative and unique human model for studying the impacts of severe physical and psychological stress on the gut-brain axis in a realistic environment.To determine changes in intestinal barrier and BBB permeability during stressful military survival training and identify relationships between those changes and markers of stress, inflammation, cognitive performance, and mood state.Seventy-one male U.S. Marines (25.2 ± 2.6 years) were studied during Survival, Evasion, Resistance, and Escape (SERE) training. Measurements were conducted on day 2 of the 10-day classroom phase of training (PRE), following completion of the 7.5-day field-based simulation phase of the training (POST), and following a 27-day recovery period (REC). Fat-free mass (FFM) was measured to assess the overall physiologic impact of the training. Biomarkers of intestinal permeability (liposaccharide-binding protein [LBP]) and BBB permeability (S100 calcium-binding protein B [S100B]), stress (cortisol, dehydroepiandrosterone sulfate [DHEA-S] epinephrine, norepinephrine) and inflammation (interleukin-6 [IL-6], high-sensitivity C-reactive protein [hsCRP]) were measured in blood. Cognitive performance was assessed by psychomotor vigilance (PVT) and grammatical reasoning (GR) tests, and mood state by the Profile of Mood States (total mood disturbance; TMD), General Anxiety Disorder-7 (GAD-7), and Patient Health (PHQ-9) questionnaires.FFM, psychomotor vigilance, and LBP decreased from PRE to POST, while TMD, anxiety, and depression scores, and S100B, DHEA-S, IL-6, norepinephrine, and epinephrine concentrations all increased (all p ≤ 0.01). Increases in DHEA-S were associated with decreases in body mass (p = 0.015). Decreases in FFM were associated with decreases in LBP concentrations (p = 0.015), and both decreases in FFM and LBP were associated with increases in TMD and depression scores (all p 0.05) but not with changes in cognitive performance. Conversely, increases in S100B concentrations were associated with decreases in psychomotor vigilance (p 0.05) but not with changes in mood state or LBP concentrations.Evidence of increased intestinal permeability was not observed in this military survival training-based model of severe physical and psychological stress. However, increased BBB permeability was associated with stress and cognitive decline, while FFM loss was associated with mood disturbance, suggesting that distinct mechanisms may contribute to decrements in cognitive performance and mood state during the severe physical and psychological stress experienced during military survival training.

Background Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations. Methods In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood. Conclusions OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS. Trial Registration ClinicalTrials.gov Identifier: NCT04120363.

Wells, AJ, Varanoske, AN, Coker, NA, Kozlowski, GJ, Frosti, CL, Boffey, D, Harat, I, Jahani, S, Gepner, Y, and Hoffman, JR. Effect of β-alanine supplementation on monocyte recruitment and cognition during a 24-hour simulated military operation. J Strength Cond Res 34(11): 3042-3054, 2020-Sustained military operations (SUSOPs) result in psychological stress and cognitive dysfunction, which may be related to the recruitment of classical monocytes into the brain. This study examined the effect of beta-alanine (BA) on cognition and monocyte recruitment during a simulated 24-hour SUSOP. Nineteen healthy men ingested 12-g/d BA or placebo for 14 days before an SUSOP. Monocyte chemoattractant protein-1 (MCP-1), C-C chemokine receptor-2 (CCR2), and macrophage-1-antigen (CD11b) expression were assessed through multiplex assay and flow cytometry. Psychological stress and cognition were assessed through Automated Neuropsychological Assessment Metrics (ANAM). A composite measure of cognition (COGcomp) was generated from throughput scores extracted from 7 ANAM cognitive tests. Assessments occurred at baseline (0H), 12 hours (12H), 18 hours (18H), and 24 hours (24H). Significance was accepted at p ≤ 0.05. No significant effect of BA was noted for any variable (p's0.05). The frequency and severity of symptoms of psychological stress increased significantly at 18 and 24H compared with 0 and 12H (p's0.05). COGcomp decreased significantly at 18 and 24H compared with 0 and 12H (p's ≤ 0.001). MCP-1 peaked at 18H was significantly lower at 24H compared with 18H but remained elevated at 24H compared with 0H (p's0.001). CCR2 expression was significantly lower at 12 (p = 0.031), 18, and 24H (p's0.001). CD11b expression was significantly higher at 12H (p = 0.039) and 24H (p's = 0.003). MCP-1 was negatively associated with COGcomp (β = -0.395, p = 0.002, r2 = 0.174). Neither CCR2 or CD11b was related to COGcomp (p's0.05). Cognitive dysfunction during SUSOPs is related to serum concentrations of MCP-1 but is not influenced by BA supplementation.

OBJECTIVES: High protein (HP) diets during short-term energy restriction (ER) attenuate energy-mediated reductions in muscle protein synthesis (MPS). MPS-adaptive responses to HP diets during prolonged ER are not well described. This study examined the effects of prolonged ER and HP on MPS and the synthesis rates of numerous individual muscle proteins. METHODS: Female 6-wk-old obese Zucker (lepr(fa+/fa+), n = 48) rats were randomized to one of four diet groups for 10 weeks: ad libitum-standard protein (AL-SP; 14% protein), AL-HP (35% protein), ER-SP, and ER-HP (both fed 60% of intake of AL-SP). At the start of week 10, D(2)O was administered by intraperitoneal injection and isotopic equilibrium was maintained daily by providing D(2)O in drinking water. Rats were euthanized after 1 week of labeling, and mixed-MPS (gastrocnemius), absolute mixed-MPS (mixed-MPS x muscle protein content), proteome dynamics, and protein half-lives [rate/d (k) = –ln(1-f)/d, where f is mixed-MPS and t is time in days; t1/2 (days) = ln(2)/k] were quantified. RESULTS: Mixed-MPS was not altered by energy status and protein intake. Gastrocnemius mass was lower (P

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 47.0±4.4 years, body mass 96.1±21.6 kg, body height 177±7.7 cm) group. The HVP consisted of eight sets of 10 repetitions of unilateral isokinetic concentric knee extension and eccentric knee flexion at 60°·s-1. Changes in tissue hemoglobin saturation index (TSI), tissue oxygenated hemoglobin concentration (O2Hb), deoxygenated hemoglobin (HHb), and muscle oxidation index (O2Hb-HHb) were measured during the exercise session using the near-infrared spectroscopy (NIRS). Data were analyzed using two-way mix factorial analyses of variance. Prior to exercise, TSI was significantly greater (p=.024) for YA compared to MA. Significant decreases in O2Hb and O2Hb-HHb and increases in HHb were observed during each of the eight sets relative to the rest periods (p

Testosterone (T) administration (TA) increases serum T and fat-free mass (FFM). Although TA-mediated increases in FFM may enhance physical performance, the data are largely equivocal, which may be due to differences in study populations, the magnitude of change in serum T and FFM, or the performance metrics. This meta-analysis explored effects of TA on serum T, FFM, and performance. Associations between increases in serum T and FFM were assessed, and whether changes in serum T or FFM, study population, or the performance metrics affected performance was determined. A systematic review of double-blind randomized trials comparing TA versus placebo on serum T, FFM, and performance was performed. Data were extracted from 20 manuscripts. Effect sizes (ESs) were assessed using Hedge’s g and a random effects model. Data are presented as ES (95% confidence interval). No significant correlation between changes in serum T and FFM was observed (P = .167). Greater increases in serum T, but not FFM, resulted in larger effects on performance. Larger increases in testosterone (7.26 [0.76-13.75]) and FFM (0.80 [0.20-1.41]) were observed in young males, but performance only improved in diseased (0.16 [0.05-0.28]) and older males (0.19 [0.10-0.29]). TA increased lower body (0.12 [0.07-0.18]), upper body (0.26 [0.11-0.40]), and handgrip (0.13 [0.04-0.22]) strength, lower body muscular endurance (0.38 [0.09-0.68]), and functional performance (0.20 [0.00-0.41]), but not lower body power or aerobic endurance. TA elicits increases in serum T and FFM in younger, older, and diseased males; however, the performance-enhancing effects of TA across studies were small, observed mostly in muscular strength and endurance, and only in older and diseased males.

Purpose To examine the impact of polyphenol supplementation on the recruitment, mobilization, and activation of monocyte subsets after resistance exercise. Methods Thirty-eight recreationally active males (22.1 ± 3.1 yr; 173.9 ± 7.9 cm; 77.8 ± 14.5 kg) were assigned to 28 d of polyphenol blend (PPB) supplementation, placebo (PL), or control (CON). Blood samples were obtained before (PRE) postresistance exercise, immediately (IP) postresistance exercise, 1 h (1H) postresistance exercise, 5 h (5H) postresistance exercise, 24 h (24H) postresistance exercise, and 48 h (48H) postresistance exercise (PPB/PL) or rest (CON). Fine-needle biopsies were obtained from the vastus lateralis at PRE, 1H, 5H, and 48H. Circulating concentrations of macrophage chemoattractant protein-1 (MCP-1) and fractalkine, as well as intramuscular MCP-1 were analyzed via multiplex assay. Changes in the proportions and expression of CD11b on monocyte subsets were assessed via flow cytometry. Results Circulating MCP-1 increased in PPB and PL at IP with further increases at 5H. Intramuscular MCP-1 was increased at 1H, 5H, and 48H in all groups. Classical monocyte proportions were reduced in PPB and PL at IP, and increased at 1H. Nonclassical monocytes were increased in PPB and PL at IP, whereas intermediate monocytes were increased at IP, and reduced at 1H. Intermediate monocytes were increased in PPB at 24H and 48H. CD11b expression was reduced on PPB compared with PL and CON at PRE on intermediate and nonclassical monocytes. Conclusions Resistance exercise may elicit selective mobilization of intermediate monocytes at 24H and 48H, which may be mediated by tissue damage. Additionally, polyphenol supplementation may suppress CD11b expression on monocyte subsets at rest.

β-Hydroxy-β-Methylbutyrate (HMB) is a metabolite of the branched-chain amino acid leucine and its ketoacid α-ketoisocaproate. HMB has been widely used as an ergogenic supplement to increase muscle strength, muscle hypertrophy and enhance recovery. The physiological mechanisms that underlie these benefits are related to HMB's ability to stimulate muscle protein synthesis and minimize muscle breakdown. Although evidence supporting the benefits of HMB supplementation is not conclusive, many of these studies have suffered from methodological flaws including different formulations, supplement duration and population studied. HMB in its free acid formulation is suggestive of having a greater potential for efficacy in both trained and untrained populations than its calcium-salt form. However, the evidence regarding HMB's role in limiting muscle degradation and increasing muscle protein synthesis has created an exciting interest in examining its efficacy among untrained individuals. Recent investigations examining intense training have demonstrated efficacy in maintaining muscle mass and attenuating the inflammatory response.

Powerlifting is a sport consisting of the squat, bench press, and deadlift. The overall winner is determined using the Wilks formula to make comparisons across weight classes. To date, literature e...

Gordon, JA III, Hoffman, JR, Arroyo, E, Varanoske, AN, Coker, NA, Gepner, Y, Wells, AJ, Stout, JR, and Fukuda, DH. Comparisons in the recovery response from resistance exercise between young and middle-aged men. J Strength Cond Res 31(12): 3454-3462, 2017-The purpose of this study was to compare the effects of a bout of high-volume isokinetic resistance exercise protocol (HVP) on lower-body strength and markers of inflammation and muscle damage during recovery between young and middle-aged adult men. Nineteen recreationally trained men were classified as either a young adult (YA: 21.8 ± 2.0 years; 90.7 ± 11.6 kg) or a middle-aged adult (MA: 47.0 ± 4.4 years; 96.0 ± 21.5 kg) group. The HVP consisted of 8 sets of 10 repetitions, with 1 minute of rest between each set, performed on an isokinetic dynamometer at 60°·s. Maximal voluntary isometric contractions and isokinetic peak torque (PKT) and average torque (AVGT) (measured at 240° and 60°·s, respectively) were assessed at baseline (BL), immediately post (IP), 120 minutes, 24, and 48 hours after HVP. Blood was obtained at BL, IP, 30, 60, 120 minute, 24, and 48 hours after HVP to assess muscle damage and inflammation. All performance data were analyzed using repeated measures analysis of covariance, whereas all inflammatory and muscle damage markers were analyzed using a 2-way (time × group) repeated measures analysis of variance. Results revealed no between-group differences for PKT, AVGT, or rate of torque development at 200 ms (RTD200). No between-group differences in myoglobin, creatine kinase, C-reactive protein, or interleukin-6 were observed. Although BL differences in muscle performance were observed between YA and MA, no between-group differences were noted in performance recovery measures from high-volume isokinetic exercise in recreationally trained men. These results also indicate that the inflammatory and muscle damage response from high-volume isokinetic exercise is similar between recreationally trained, young, and middle-aged adult men.

β-alanine (BA) is a nonproteogenic amino acid that combines with histidine to form carnosine. The amount taken orally in individual doses, however, is limited due to symptoms of paresthesia that are associated with higher doses. The use of a sustained-release formulation has been reported to reduce the symptoms of paresthesia, suggesting that a greater daily dose may be possible. The purpose of the present study was to determine whether increasing the daily dose of BA can result in a similar increase in muscle carnosine in a reduced time.Eighteen men and twelve women were randomized into either a placebo (PLC), 6-g BA (6G), or 12-g BA (12G) groups. PLC and 6G were supplemented for 4 weeks, while 12G was supplemented for 2 weeks. A resting blood draw and muscle biopsy were obtained prior to (PRE) and following (POST) supplementation. Plasma and muscle metabolites were measured by high-performance liquid chromatography. The loss in peak torque (ΔPT) was calculated from maximal isometric contractions before and after 250 isokinetic kicks at 180°·secBoth 12G (p = 0.026) and 6G (p = 0.004) increased muscle carnosine compared to PLC. Plasma histidine was decreased from PRE to POST in 12G compared to PLC (p = 0.002) and 6G (p = 0.001), but no group x time interaction (p = 0.662) was observed for muscle histidine. No differences were observed for any hematological measure (e.g., complete blood counts) or in symptoms of paresthesia among the groups. Although no interaction was noted in ΔPT, a trend (p = 0.073) was observed.Results of this investigation indicate that a BA supplementation protocol of 12 g/d

The purpose of this study was to compare the coadministration of the probiotic Bacillus coagulans GBI-30, 6086 (BC30) with β-hydroxy-β-methylbutyrate (HMB) calcium (CaHMB) to CaHMB alone on inflammatory response and muscle integrity during 40 days of intense military training. Soldiers were randomly assigned to one of two groups: CaHMB with BC30 (CaHMBBC30; n = 9) or CaHMB with placebo (CaHMBPL, n = 9). A third group of participants served as a control (CTL; n = 8). During the first 28 days soldiers were garrisoned on base and participated in the same training tasks. During the final 2 wk soldiers navigated 25–30 km per night in difficult terrain carrying ~35 kg of equipment. All assessments (blood draws and diffusion tensor imaging to assess muscle integrity) were conducted before and ~12 h after final supplement consumption. Analysis of covariance was used to analyze all blood and muscle measures. Significant attenuations were noted in IL-1β, IL-2, IL-6, CX3CL1, and TNF-α for both CaHMBBC30 and CaHMBPL compared with CTL. Plasma IL-10 concentrations were significantly attenuated for CaHMBBC30 compared with CTL only. A significant decrease in apparent diffusion coefficients was also observed for CaHMBBC30 compared with CaHMBPL. Results provide further evidence that HMB supplementation may attenuate the inflammatory response to intense training and that the combination of the probiotic BC30 with CaHMB may be more beneficial than CaHMB alone in maintaining muscle integrity during intense military training. NEW & NOTEWORTHY β-Hydroxy-β-methylbutyrate (HMB) in its free acid form was reported to attenuate inflammation and maintain muscle integrity during military training. However, this formulation was difficult to maintain in the field. In this investigation, soldiers ingested HMB calcium (CaHMB) with Bacillus coagulans (BC30) or CaHMB alone during 40 days of training. Results indicated that CaHMB attenuated the inflammatory response and that BC30 combined with CaHMB may be more beneficial than CaHMB alone in maintaining muscle integrity during intense military training.

Introduction: β-alanine (BA) supplementation may improve cognition and mitigate symptoms of anxiety and depression associated with aging, neurological disorders, and physical exertion, which has be...

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 position on VL morphology and its relationship with lower-body performance. Cross-sectional area (CSA), muscle thickness (MT), pennation angle (PA), echo intensity (UnCorEI), subcutaneous adipose tissue thickness (SFT), and echo intensity corrected for SFT (CorEI) were assessed in 31 resistance-trained males (23.0 ± 2.1 yrs; 1.79 ± 0.08 m; 87.4 ± 11.7 kg) immediately after transitioning from standing to supine (IP), after 15 min of standing (ST), and after 15 min of rest in three recumbent positions: supine (SUP), dominant lateral recumbent (DLR), non-dominant lateral recumbent (NDLR). Participants also completed unilateral vertical jumps, isometric/isokinetic tests, and a one-repetition maximum leg press. CSA, MT, PA, and SFT were greater in ST compared to NDLR, DLR, and SUP (p < 0.05). CSA, UnCorEI, and CorEI were different between recumbent positions; however no differences were observed for MT, PA, and SFT. Different magnitudes of relationships were observed between muscle morphological characteristics measured after rest in different positions and performance variables. Muscle morphology in IP generally appears to be the best predictor of performance for most variables, although utilizing the NDLR and DLR positions may provide comparable results, whereas morphology measured in ST and SUP provide weaker relationships with physical performance. IP also requires less time and fewer requirements on the technician and subject, thus researchers should consider this positioning for VL examination.

INTRODUCTION Echo intensity of skeletal muscle measured by means of ultrasonography has been used to assess muscle quality, however, the heterogeneity of echo intensity has not been thoroughly investigated. Therefore, this study examined echo intensity in different sections of panoramic ultrasound images captured in the transverse plane. METHODS Echo intensity of the vastus lateralis was assessed in 24 men (20.2 ± 1.6 years) using panoramic ultrasonography. Echo intensity homogeneity was examined by dividing each image into 3 compartments of equal horizontal length (tertiles). RESULTS No differences were found between echo intensity of the anterior tertile (59.1 ± 9.1 AU), posterior tertile (56.4 ± 9.9 AU), lateral tertile (58.7 ± 9.9 AU), or the overall panoramic image (58.0 ± 8.8 AU). CONCLUSIONS Echo intensity of the vastus lateralis appears to be homogeneous as assessed in the transverse plane. Further research is necessary to determine if still imaging is sufficient to obtain an accurate measure of echo intensity. Muscle Nerve 56: 93-98, 2017.

Muscle morphological characteristics obtained via ultrasonography have been used to quantify the size, architecture, and quality of skeletal muscle. Previous research has utilized varying ultrasonographic techniques, however there is little information comparing these different techniques. Muscle morphological characteristics, including cross-sectional area (CSA), muscle thickness (MT), echo intensity (EI), and subcutaneous adipose tissue thickness (SubQ) were assessed in 24 males (20.2 ± 1.6 y) via three panoramic-images captured in the transverse plane (PTI) and three still-images captured in the longitudinal plane (SLI). Cross-sectional area of PTI was significantly greater than CSA of SLI (P

AB The innate immune response is generally considered to have an important role in tissue remodeling after resistance exercise. Purpose: The purpose of this study was to compare changes in markers of monocyte recruitment after an acute bout of high-intensity (HVY) versus high-volume (VOL) lower-body resistance exercise. Methods: Ten resistance-trained men (24.7 +/- 3.4 yr, 90.1 +/- 11.3 kg, 176.0 +/- 4.9 cm) performed each protocol in a randomized, counterbalanced order. Blood samples were collected at baseline, immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Plasma concentrations of monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-[alpha]), myoglobin, and cortisol were measured via assay. Tumor necrosis factor receptor 1 (TNFr1), macrophage-1 antigen (cluster of differentiation 11b [CD11b]), and C-C chemokine receptor 2 (CCR2) expression levels were measured using flow cytometry. TNFr1 and CD11b were assessed on CD14++CD16- monocytes, whereas CCR2 was assessed on CD14+ monocytes. Results: Plasma myoglobin concentrations were significantly greater after HVY compared with VOL (P < 0.001). Changes in plasma TNF-[alpha], MCP-1, and expression levels of CCR2 and CD11b were similar between HVY and VOL. When collapsed across groups, TNF-[alpha] was significantly increased at IP, 30P, 1H, and 2H (P values < 0.05), whereas MCP-1 was significantly elevated at all postexercise time points (P values < 0.05). CCR2 expression on CD14+ monocytes was significantly lower at IP, 1H, 2H, and 5H (P values < 0.05). CD11b expression on CD14++ CD16- was significantly greater at IP (P < 0.014) and 1H (P = 0.009). TNFr1 expression did not differ from baseline at any time point. Plasma cortisol concentrations did not seem to be related to receptor expression. Conclusions: Results indicate that both HVY and VOL protocols stimulate a robust proinflammatory response. However, no differences were noted between resistance exercise training paradigms.

β-Alanine is a nonproteogenic amino acid that combines with histidine to form a dipeptide molecule known as carnosine. Carnosine is an H+ buffer that is especially useful in preventing the decline in muscle pH during high-intensity exercise. β-Alanine has been shown to be the rate-limiting precursor of carnosine formation, and therefore supplementation with β-alanine increases muscle carnosine. β-Alanine supplementation has ergogenic effects on exercise performance, specifically in high-intensity events for 1–4 min. However, carnosine has been suggested to have various other roles in the body, including acting as an antioxidant, antiglycating agent, and ion chelator, which may have significant effects on aging and other health benefits. Besides β-alanine supplementation, carnosine content is dependent on various other factors, such as diet, gender, and training status. This chapter aims to review the ergogenic effects of β-alanine supplementation on exercise performance and highlight the beneficial effects of carnosine content on health.

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 paresthesia and extend the period of supply to muscle for carnosine synthesis. The purpose of this investigation was to compare 28 days of SR and RR formulations of β-alanine (6 g day-1) on changes in carnosine content of the vastus lateralis and muscle fatigue. Thirty-nine recreationally active men and women were assigned to one of the three groups: SR, RR, or placebo (PLA). Participants supplementing with SR and RR formulations increased muscle carnosine content by 50.1% (3.87 mmol kg-1ww) and 37.9% (2.62 mmol kg-1ww), respectively. The change in muscle carnosine content in participants consuming SR was significantly different (p = 0.010) from those consuming PLA, but no significant difference was noted between RR and PLA (p = 0.077). Although participants ingesting SR experienced a 16.4% greater increase in muscle carnosine than RR, fatigue during maximal voluntary isometric contractions was significantly attenuated in both SR and RR compared to PLA (p = 0.002 and 0.024, respectively). Symptoms of paresthesia were significantly more frequent in RR compared to SR, the latter of which did not differ from PLA. Results of this study demonstrated that only participants consuming the SR formulation experienced a significant increase in muscle carnosine. Differences in the muscle carnosine response between these formulations may have practical significance for athletic populations in which small changes may have important implications on performance.

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 levels may enhance cognitive performance and increase resiliency to stress. These benefits are thought to result from carnosine's potential role as an antioxidant. This review will discuss these new findings including recent investigations examining β-alanine supplementation and increased resiliency to posttraumatic stress and mild traumatic brain injury. This review will focus on the physiology of carnosine, the effect of β-alanine ingestion on carnosine elevations, and the potential ergogenic benefits it has for competitive and tactical athletes.

Tumor necrosis factor-alpha (TNF-α) has been shown to be implicated in both muscle regeneration and muscle wasting. However, it remains unclear whether TNF-α is responsible for the age-related losses in muscle size and function. Also, due to the high clearance rate of TNF-α from circulation, analyzing the circulating levels of soluble TNF-α receptors 1 and 2 (STNFR1 and STNFR2) may provide a better indication of inflammatory events. The aim of this study was to examine changes in circulating concentrations of TNF-α, STNFR1, and STNFR2 following acute eccentric exercise in young (YA) and middle-aged (MA) men.Nine YA (N=9, 21.8±2.2y, 179.5±4.9cm, 91.2±12.2kg, 21.8±4.3% body fat) and ten MA (N=10, 47.0±4.4y, 176.8±7.6cm; 96.0±21.5kg, 25.4±5.3% body fat) men completed an acute muscle damaging protocol (MDP). Blood samples were obtained at baseline (BL), immediately (IP), 30-minute (30P), 60-minute (60P), 120-minute (120P), 24-hour (24H), and 48-hour (48H) post-MDP. Lower body performance was assessed via isokinetic dynamometer at BL, IP, 120P, 24H, and 48H.YA displayed higher values of peak torque (p=0.023) and mean torque (p=0.036) at BL. No significant group differences were observed for markers of muscle damage or TNF-α. Plasma concentrations of TNF-α were unchanged following MDP. STNFR1 concentrations were significantly higher in the YA group compared to MA (p=0.036). Significant time effects were observed for STNFR1 (p0.001) and STNFR2 (p=0.001). With both groups combined, serum STNFR1 was decreased at 30P (p=0.001), while STNFR2 was decreased at 30P (p=0.008), 60P (p=0.003), and 120P (p=0.002) relative to BL.The pro-inflammatory response to muscle damage does not appear to decline at middle age when individuals are recreationally trained. However, young men showed significantly higher serum STNFR1 concentrations than middle age men. This may suggest that natural inhibitors of TNF-α decline as early as middle age.

β-Alanine (BA) supplementation results in elevated intramuscular carnosine content, enhancing buffering capacity during intense exercise. Although men have greater muscle carnosine content than women, elevations still appear to occur despite high baseline levels. Recent research has suggested that BA supplementation may also reduce muscle l-histidine. Thus, the purpose of this investigation was to compare 28 days of BA (6 g·d-1) supplementation in men and women on performance and muscle carnosine, l-histidine, and BA. We hypothesized that supplementation would result in similar elevations in carnosine and performance between sexes and decrease l-histidine. Twenty-six men and women were assigned either BA or placebo (PLA). At baseline, a trend toward greater carnosine (P = .069) was observed in men, and intramuscular BA content was significantly (P ≤ .05) greater in men. Statistical analysis was performed using magnitude-based inferences. Changes in muscle carnosine were likely and very likely greater after BA supplementation compared with PLA in men and women, respectively, but changes were unclear between sexes (mean sex difference: 2.50 ± 4.30 mmol·kg-1 ww). The attenuation of exercise fatigue was likely greater in BA compared with PLA, but the change was unclear between sexes (mean sex difference: 14.0 ± 39.0 Nm). Changes in muscle BA following supplementation was unclear in men, likely elevated in women, but unclear between sexes (mean sex difference: 0.03 ± 0.42 mmol·kg-1 ww). Changes in muscle l-histidine were unclear in men and women, and unclear between sexes (mean sex difference: 0.09 ± 0.13 mmol·kg-1 ww). In conclusion, BA supplementation increased muscle carnosine and attenuated fatigue in men and women similarly but did not reduce muscle l-histidine.

Attenuating TNFα/TNFr1 signaling in monocytes has been proposed as a means of mitigating inflammation. The purpose of this study was to examine the effects of a milk protein supplement on TNFα and monocyte TNFr1 expression. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) ingested supplement (SUPP) or placebo (PL) immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL), immediately (IP), 30-min (30P), 1-h (1H), 2-h (2H), and 5-h (5H) post-exercise to assess plasma concentrations of myoglobin; tumor necrosis factor-alpha (TNFα); and expression of tumor necrosis factor receptor 1 (TNFr1) on classical, intermediate, and non-classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Plasma TNFα concentrations were “likely attenuated” (91.6% likelihood effect) from BL to 30P in the SUPP group compared with PL (d = 0.87; mean effect: 2.3 ± 2.4 pg mL−1). TNFr1 expressions on classical (75.9% likelihood effect) and intermediate (93.0% likelihood effect) monocytes were “likely attenuated” from BL to 2H in the SUPP group compared with PL (d = 0.67; mean effect: 510 ± 670 RFU, and d = 1.05; mean effect: 2500 ± 2300 RFU, respectively). TNFr1 expression on non-classical monocytes was “likely attenuated” (77.6% likelihood effect) from BL to 1H in the SUPP group compared with PL (d = 0.69; mean effect: 330 ± 430 RFU). Ingestion of a milk protein supplement immediately post-exercise appears to attenuate both plasma TNFα concentrations and TNFr1 expression on monocyte subpopulations in resistance-trained men.

Purpose The purpose of this study was to compare the physiological responses of a high-volume (HV; 8 sets of 10 repetitions) versus high-intensity (HI; 8 sets of 3 repetitions) exercise protocol in resistance-trained men. Methods Twelve men (24.5 ± 4.2 years; 82.3 ± 8.4 kg; 175.2 ± 5.5 cm) with 6.3 ± 3.4 years of resistance training experience performed each protocol in a counterbalanced, randomized order. Performance [counter movement jump peak power (CMJP), isokinetic (ISOK) and isometric leg extension (MVIC), isometric mid-thigh pull (IMTP), and isometric squat (ISQ)] and muscle morphological [cross-sectional area (CSA) of vastus lateralis] assessments were performed at baseline (BL), 30-min (P-30 min), 24-h (P-24 h), 48-h (P-48 h), and 72-h (P-72 h) post-exercise for each testing session. In addition, endocrine (testosterone and cortisol), inflammatory [interleukin-6 (IL-6) and C-reactive protein (CRP)], and markers of muscle damage [creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb)] were assessed at the same time points. Results Significantly greater reductions in CMJP (p

The purpose of this study was to compare the coadministration of the probiotic

SummaryIntroduction Due to the potential for intramuscular fluid shifts from changing body position, researchers often utilize a 10- to 15-min period of supine rest as a standardizing procedure prior to ultrasound assessment of the lower limbs. However, no previous research has observed the changes in muscle morphological characteristics via ultrasonography of the lower limbs depending on the length of time of supine rest to determine whether 10–15 min of supine rest is necessary. The aim of this study was to examine changes in muscle morphology of the vastus lateralis (VL) at various time-points over the course of 15 min of supine rest. Methods Muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the VL were assessed in 24 adults at four time-points including the following: immediately upon moving from a standing to supine position (T0), after 5 (T5), 10 (T10) and 15 min (T15) of lying in a supine position. Results CSA significantly decreased from T0 to T10 (P = 0·001) and T15 (P

Echo intensity of skeletal muscle measured by means of ultrasonography has been used to assess muscle quality, however, the heterogeneity of echo intensity has not been thoroughly investigated. Therefore, this study examined echo intensity in different sections of panoramic ultrasound images captured in the transverse plane.Echo intensity of the vastus lateralis was assessed in 24 men (20.2 ± 1.6 years) using panoramic ultrasonography. Echo intensity homogeneity was examined by dividing each image into 3 compartments of equal horizontal length (tertiles).No differences were found between echo intensity of the anterior tertile (59.1 ± 9.1 AU), posterior tertile (56.4 ± 9.9 AU), lateral tertile (58.7 ± 9.9 AU), or the overall panoramic image (58.0 ± 8.8 AU).Echo intensity of the vastus lateralis appears to be homogeneous as assessed in the transverse plane. Further research is necessary to determine if still imaging is sufficient to obtain an accurate measure of echo intensity. Muscle Nerve 56: 93-98, 2017.

Sustained military operations (SUSOPs) are associated with performance decrements and cognitive dysfunction. β‐Alanine (BA) supplementation may have a role in increasing soldier resiliency by enhancing muscle‐buffering capacity and reducing oxidative stress. The purpose of this study was to examine the effects of BA on physical performance, cognition, endocrine function, and inflammation during a 24 h simulated SUSOP. Nineteen males were randomized into one of two groups: BA (n = 10) or placebo (n = 9; PLA) (12 g/day) for 14 days preceding the 24 h SUSOP. Assessments were performed at 0 h (0H), 12 h (12H), and 24 h (24H) during the SUSOP. No changes in visual tracking ability, jump power, or upper‐body muscular endurance were observed between groups or time points (P's > 0.05). Increases in subjective feelings of soreness and fatigue were noted at 12H compared to 0H (P

Background The purpose of this study was to examine the ergogenic benefits of Turkish coffee consumed an hour before exercise. In addition, metabolic, cardiovascular, and subjective measures of energy, focus and alertness were examined in healthy, recreationally active adults who were regular caffeine consumers (>200 mg per day). Methods Twenty males (n = 10) and females (n = 10), age 24.1 ± 2.9 y; height 1.70 ± 0.09 m; body mass 73.0 ± 13.0 kg (mean ± SD), ingested both Turkish coffee [3 mg · kg−1 BW of caffeine, (TC)], and decaffeinated Turkish coffee (DC) in a double-blind, randomized, cross-over design. Performance measures included a 5 km time trial, upper and lower body reaction to visual stimuli, and multiple object tracking. Plasma caffeine concentrations, blood pressure (BP), heart rate and subjective measures of energy, focus and alertness were assessed at baseline (BL), 30-min following coffee ingestion (30+), prior to endurance exercise (PRE) and immediately-post 5 km (IP). Metabolic measures [VO2, VE, and respiratory exchange rate (RER)] were measured during the 5 km. Results Plasma caffeine concentrations were significantly greater during TC (p 0.05) were noted in any of the other performance or metabolic measures. Conclusions Acute ingestion of TC resulted in a significant elevation in plasma caffeine concentrations within 30-min of consumption. TC ingestion resulted in significant performance benefits in reaction time and an increase in subjective feelings of energy in habitual caffeine users. No significant differences were noted in time for the 5 km between trials, however 60 % of the participants performed the 5 km faster during the TC trial and were deemed responders. When comparing TC to DC in responders only, significantly faster times were noted when consuming TC compared to DC. No significant benefits were noted in measures of cognitive function.