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Rationale: Firefighters are at risk for cardiovascular disease due to occupational-related inflammation, oxidative stress, and lifestyle practices. Astaxanthin (AX) possesses anti-inflammatory/antioxidant and purported ergogenic properties. This study examined the impact of supplementing the diet with 12 mg/d AX for four weeks on markers of inflammation, oxidative stress, cardiometabolic health, exercise capacity, and occupation-related performance in career firefighters., Methods: In a randomized, double-blinded, placebo-controlled, crossover fashion, 15 male career firefighters (34.5 ± 7.4 years; 177.7 ± 7.0 cm; 95.6 ± 12.0 kg; 30.1 ± 2.9 kg/m 2 ; 11.03 ± 6.85 years of service) ingested 12 mg/d of AX (AstaReal®, AstaReal AB, Nacka, SWE) or placebo (PLA) for four weeks while following a standardized resistance training program. After each treatment, testing sessions were completed to assess inflammatory markers, oxidative stress markers, cardiopulmonary exercise capacity, and performance to a fire ground test (FGT) consisting of nine fire suppressive activities. Data were analyzed using general linear model (GLM) analysis with repeated measures. Clinical significance was assessed via mean changes from baseline with 95% confidence intervals., Results: Analysis of mean percent changes from baseline revealed that AX supplementation lessened the inflammatory response to to performing an incremental maximal exercise test and attenuated increases in interleukin-1β, cortisol, and uric acid in response to performing fire suppressive activities compared to when they ingested PLA. However, most of these effects were within groups rather than between groups. Additionally, there was evidence that AX ingestion increased the ventilatory anaerobic threshold. Four weeks of AX supplementation did not significantly affect fasting markers of oxidative stress, blood lipids, performance during the FGT, general clinical chemistry panels, or self-reported side effects., Conclusions: Results provide some evidence that AX supplementation may help mediate occupation-related inflammation in response to high-intensity, short-duration exercise in firefighters. More research is warranted to determine if long-term supplementation can improve cardiometabolic risk in this population., Clinical Trial Registration: ISRCTN10901752.

Metabolic conditions, such as gout, can result from elevated uric acid (UA) levels. Consuming high-purine meals increases UA levels. Therefore, people with hyperuricemia typically must avoid ingesting such foods. Polyphenols have been shown to reduce uric acid levels and tart cherries (TCs) are a rich source of phenolic and anthocyanin compounds. This proof-of-concept study evaluated whether ingesting TCs with a purine-rich meal affects the uricemic response. Methods: A total of 25 adults (15 males and 10 females, 85.0 ± 17 kg, 40.6 ± 9 years, 29.1 ± 4.9 kg/m 2 ) with elevated fasting UA levels (5.8 ± 1.3 mg/dL) donated a fasting blood sample. In a randomized, double-blind, crossover, placebo-controlled, counterbalanced manner, participants ingested capsules containing 960 mg of a placebo (PLA) or concentrated TC powder containing 20.7 mg of proanthocyanins with a serving of hot soup (10 g of carbohydrate, 2 g protein, and 1 g fat) containing 3 g of purines (1 g of adenosine 5'-monophosphate, 1 g of disodium 5'-guanylate, and 1 g of disodium 5'-inosinate). Blood samples were obtained at 0, 60, 120, 180, and 240 min after ingestion to assess changes in uric acid levels and pharmacokinetic profiles. Cell blood counts, a comprehensive metabolic panel, cytokines, inflammatory markers, and subjective side effects ratings were analyzed on baseline (0 min) and post-treatment (240 min) samples. Participants continued consuming two capsules/day of the assigned treatment for one week and then repeated the experiment. Participants observed a 14-day washout and then repeated the experiment while ingesting the alternate treatment. Data were analyzed using general linear model (GLM) statistics with repeated measures, pairwise comparisons, and percentage change from baseline with 95% confidence intervals (CIs). Results: No statistically significant interaction effects or differences between treatments were seen in uric acid levels or PK profiles. Analysis of percent changes from baseline revealed that TC ingestion reduced the blood glucose levels following the ingestion of the high-purine meal (-4.2% [-7.7, -0.7], p = 0017). Additionally, there was some evidence that TC ingestion attenuated the increase from baseline in IL-1β and IL-10 and increased INF-γ. No significant differences were seen in the remaining health markers or subjective side effects ratings. Conclusions: Acute and one-week TC supplementation did not affect the uricemic response to ingesting a high-purine meal in individuals with mildly elevated UA levels. However, there was some evidence that TC supplementation may blunt the glycemic response to ingesting a meal and influence some inflammatory cytokines. Registered clinical trial NCT04837274.

Background: Previous trials have displayed augmented intracellular vitamin C concentrations in the leukocytes at 24 h after acute supplementation with 1000 mg calcium ascorbate (CA), compared to ascorbic acid (AA)., Objective: The primary objective was to evaluate comparative leukocyte vitamin C accumulation kinetics over 32 h following acute 250 mg or 500 mg doses from the two sources. Secondary objectives were to evaluate neutrophil phagocytic function and lymphocyte differentiation between the two sources of vitamin C., Methods: Ninety-three healthy females (250 mg, n = 27; 500 mg, n = 24) and males (250 mg, n = 19; 500 mg, n = 23) were assigned to ingest a single dose of CA or AA providing 250 mg or 500 mg of vitamin C in two separate double-blind, randomized crossover trials., Results: There were no significant differences in the primary or secondary outcomes between the two treatments in the 250 mg low-dose study. Conversely, there was evidence that ingestion of 500 mg of CA increased DHA in plasma, increased neutrophil functionality during the first 8 h of the PK study, promoted increased natural killer cells, and altered weight-adjusted PK profiles, suggesting greater volume distribution and clearance from the blood., Conclusions: These findings indicate that 500 mg of CA may promote some immune benefits compared to 500 mg of AA ingestion.

Background/Objectives: Firefighters, tactical police officers, and warriors often engage in periodic, intermittent, high-intensity physical work in austere environmental conditions and have a heightened risk of premature mortality. In addition, tough decision-making challenges, routine sleep deprivation, and trauma exacerbate this risk. Therefore, identifying strategies to bolster these personnel's health and occupational performance is critical. Creatine monohydrate (CrM) supplementation may offer several benefits to firefighters and tactical athletes (e.g., police, security, and soldiers) due to its efficacy regarding physical performance, muscle, cardiovascular health, mental health, and cognitive performance. Methods: We conducted a narrative review of the literature with a focus on the benefits and application of creatine monohydrate among firefighters. Results: Recent evidence demonstrates that CrM can improve anaerobic exercise capacity and muscular fitness performance outcomes and aid in thermoregulation, decision-making, sleep, recovery from traumatic brain injuries (TBIs), and mental health. Emerging evidence also suggests that CrM may confer an antioxidant/anti-inflammatory effect, which may be particularly important for firefighters and those performing tactical occupations exposed to oxidative and physiological stress, which can elicit systemic inflammation and increase the risk of chronic diseases. Conclusions: This narrative review highlights the potential applications of CrM for related tactical occupations, with a particular focus on firefighters, and calls for further research into these populations.

Phaeodactylum tricornutum ( PT ) is a microalgae extract that contains fucoxanthin and has been shown to enhance cognitive function in younger populations. The present study assessed if PT supplementation affects cognition in healthy, young-old, physically active adults with self-perceptions of cognitive and memory decline., Methods: Forty-three males and females (64.3 ± 6.0 years, 79.8 ± 16.0 kg, 27.0 ± 4.0 kg/m 2 ) with perceptions of cognitive and memory decline completed the double-blind, randomized, parallel-arm, placebo-controlled intervention clinical trial. Participants were counterbalanced by sex and BMI and randomly allocated to their respective 12-week supplementation interventions, which were either the placebo (PL) or 1100 mg/day of PT containing 8.8 mg of fucoxanthin (FX). Fasting blood samples were collected, and cognitive assessments were performed during the testing session at 0, 4, and 12 weeks of intervention. The data were analyzed by multivariate and univariate general linear model (GLM) analyses with repeated measures, pairwise comparisons, and mean changes from baseline analysis with 95% confidence intervals (CIs) to assess the clinical significance of the findings., Results: FX supplementation significantly affected ( p < 0.05) or exhibited tendencies toward significance ( p > 0.05 to p < 0.10 with effect sizes ranging from medium to large) for word recall, picture recognition reaction time, Stroop color-word test, choice reaction time, and digit vigilance test variables. Additionally, FX supplementation promoted a more consistent clinical improvement from baseline values when examining mean changes with 95% CIs, although most differences were seen over time rather than between groups., Conclusions: The results demonstrate some evidence that FX supplementation can improve working and secondary memory, vigilance, attention, accuracy, and executive function. There was also evidence that FX promoted more positive effects on insulin sensitivity and perceptions about sleep quality with no negative effects on clinical blood panels or perceived side effects. Additional research should investigate how FX may affect cognition in individuals perceiving memory and cognitive decline. Registered clinical trial #NCT05759910.

Background: Ashwagandha has been reported to reduce stress and attenuate cognitive decline associated with inflammation and neurodegeneration in clinical populations. However, the effects as a potential nootropic nutrient in younger populations are unclear. This study examined the effects of liposomal ashwagandha supplementation on cognitive function, mood, and markers of health and safety in healthy young men and women., Methods: 59 men and women (22.7 ± 7 yrs., 74.9 ± 16 kg, 26.2 ± 5 BMI) fasted for 12 h, donated a fasting blood sample, and were administered the COMPASS cognitive function test battery (Word Recall, Word recognition, Choice Reaction Time Task, Picture Recognition, Digit Vigilance Task, Corsi Block test, Stroop test) and profile of mood states (POMS). In a randomized and double-blind manner, participants were administered 225 mg of a placebo (Gum Arabic) or ashwagandha ( Withania somnifera ) root and leaf extract coated with a liposomal covering. After 60-min, participants repeated cognitive assessments. Participants continued supplementation (225 mg/d) for 30 days and then returned to the lab to repeat the experiment. Data were analyzed using a general linear model (GLM) univariate analysis with repeated measures and pairwise comparisons of mean changes from baseline with 95% confidence intervals (CI)., Results: Ashwagandha supplementation improved acute and/or 30-day measures of Word Recall (correct and recalled attempts), Choice Reaction Time (targets identified), Picture Recognition ("yes" correct responses, correct and overall reaction time), Digit Vigilance (correct reaction time), Stroop Color-Word (congruent words identified, reaction time), and POMS (tension and fatigue) from baseline more consistently with several differences observed between groups., Conclusion: Results support contentions that ashwagandha supplementation (225 mg) may improve some measures of memory, attention, vigilance, attention, and executive function while decreasing perceptions of tension and fatigue in younger healthy individuals. Retrospectively registered clinical trial ISRCTN58680760.

In 2011, we published a paper providing an overview about the bioavailability, efficacy, and regulatory status of creatine monohydrate (CrM), as well as other "novel forms" of creatine that were being marketed at the time. This paper concluded that no other purported form of creatine had been shown to be a more effective source of creatine than CrM, and that CrM was recognized by international regulatory authorities as safe for use in dietary supplements. Moreover, that most purported "forms" of creatine that were being marketed at the time were either less bioavailable, less effective, more expensive, and/or not sufficiently studied in terms of safety and/or efficacy. We also provided examples of several "forms" of creatine that were being marketed that were not bioavailable sources of creatine or less effective than CrM in comparative effectiveness trials. We had hoped that this paper would encourage supplement manufacturers to use CrM in dietary supplements given the overwhelming efficacy and safety profile. Alternatively, encourage them to conduct research to show their purported "form" of creatine was a bioavailable, effective, and safe source of creatine before making unsubstantiated claims of greater efficacy and/or safety than CrM. Unfortunately, unsupported misrepresentations about the effectiveness and safety of various "forms" of creatine have continued. The purpose of this critical review is to: (1) provide an overview of the physiochemical properties, bioavailability, and safety of CrM; (2) describe the data needed to substantiate claims that a "novel form" of creatine is a bioavailable, effective, and safe source of creatine; (3) examine whether other marketed sources of creatine are more effective sources of creatine than CrM; (4) provide an update about the regulatory status of CrM and other purported sources of creatine sold as dietary supplements; and (5) provide guidance regarding the type of research needed to validate that a purported "new form" of creatine is a bioavailable, effective and safe source of creatine for dietary supplements. Based on this analysis, we categorized forms of creatine that are being sold as dietary supplements as either having strong, some, or no evidence of bioavailability and safety. As will be seen, CrM continues to be the only source of creatine that has substantial evidence to support bioavailability, efficacy, and safety. Additionally, CrM is the source of creatine recommended explicitly by professional societies and organizations and approved for use in global markets as a dietary ingredient or food additive.

Inositol stabilized arginine silicate (ASI) ingestion has been reported to increase nitric oxide levels while inositol (I) has been reported to enhance neurotransmission. The current study examined whether acute ASI + I (Inositol-enhanced bonded arginine silicate) ingestion affects cognitive function in e-sport gamers. In a double blind, randomized, placebo controlled, and crossover trial, 26 healthy male (n = 18) and female (n = 8) experienced gamers (23 ± 5 years, 171 ± 11 cm, 71.1 ± 14 kg, 20.7 ± 3.5 kg/m 2 ) were randomly assigned to consume 1600 mg of ASI + I (nooLVL ® , Nutrition 21) or 1600 mg of a maltodextrin placebo (PLA). Prior to testing, participants recorded their diet, refrained from consuming atypical amounts of stimulants and foods high in arginine and nitrates, and fasted for 8 h. During testing sessions, participants completed stimulant sensitivity questionnaires and performed cognitive function tests (i.e., Berg-Wisconsin Card Sorting task test, Go/No-Go test, Sternberg Task Test, Psychomotor Vigilance Task Test, Cambridge Brain Sciences Reasoning and Concentration test) and a light reaction test. Participants then ingested treatments in a randomized manner. Fifteen minutes following ingestion, participants repeated tests (Pre-Game). Participants then played their favorite video game for 1-h and repeated the battery of tests (Post-Game). Participants observed a 7-14-day washout period and then replicated the study with the alternative treatment. Data were analyzed by General Linear Model (GLM) univariate analyses with repeated measures using weight as a covariate, paired t -tests (not adjusted to weight), and mean changes from baseline with 95% Confidence Intervals (CI). Pairwise comparison revealed that there was a significant improvement in Sternberg Mean Present Reaction Time (ASI + I vs. PLA; p < 0.05). In Post-Game assessments, 4-letter Absent Reaction Time ( p < 0.05), 6-letter Present Reaction Time ( p < 0.01), 6-letter Absent Reaction Time ( p < 0.01), Mean Present Reaction Time ( p < 0.02), and Mean Absent Reaction Time ( p < 0.03) were improved with ASI + I vs. PLA. There was a non-significant trend in Pre-Game Sternberg 4-letter Present Reaction time in ASI + I vs. PLA ( p < 0.07). ASI + I ingestion better maintained changes in Go/No-Go Mean Accuracy and Reaction Time, Psychomotor Vigilance Task Reaction Time, and Cambridge Post-Game Visio-spatial Processing and Planning. Results provide evidence that ASI + I ingestion prior to playing video games may enhance some measures of short-term and working memory, reaction time, reasoning, and concentration in experienced gamers.

Creatine is one of the most studied and popular ergogenic aids for athletes and recreational weightlifters seeking to improve sport and exercise performance, augment exercise training adaptations, and mitigate recovery time. Studies consistently reveal that creatine supplementation exerts positive ergogenic effects on single and multiple bouts of short-duration, high-intensity exercise activities, in addition to potentiating exercise training adaptations. In this respect, supplementation consistently demonstrates the ability to enlarge the pool of intracellular creatine, leading to an amplification of the cell's ability to resynthesize adenosine triphosphate. This intracellular expansion is associated with several performance outcomes, including increases in maximal strength (low-speed strength), maximal work output, power production (high-speed strength), sprint performance, and fat-free mass. Additionally, creatine supplementation may speed up recovery time between bouts of intense exercise by mitigating muscle damage and promoting the faster recovery of lost force-production potential. Conversely, contradictory findings exist in the literature regarding the potential ergogenic benefits of creatine during intermittent and continuous endurance-type exercise, as well as in those athletic tasks where an increase in body mass may hinder enhanced performance. The purpose of this review was to summarize the existing literature surrounding the efficacy of creatine supplementation on exercise and sports performance, along with recovery factors in healthy populations.

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.

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 creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.

Vitamin D and calcium supplementation have been posited to improve body composition and different formulations of calcium may impact bioavailability. However, data are lacking regarding the combinatorial effects of exercise, diet, and calcium and/or vitamin D supplementation on body composition changes in post-menopausal women. Herein, 128 post-menopausal women (51.3 ± 4.5 years, 36.4 ± 5.7 kg/m 2 , 46.2 ± 4.5% fat) were assigned to diet and supplement groups while participating in a supervised circuit-style resistance-training program (3 d/week) over a 14-week period. Diet groups included: (1) normal diet (CTL), (2) a low-calorie, higher protein diet (LCHP; 1600 kcal/day, 15% carbohydrates, 55% protein, 30% fat), and (3) a low-calorie, higher carbohydrate diet (LCHC; 1600 kcal/day, 55% carbohydrates, 15% protein, 30% fat). Supplement groups consisted of: (1) maltodextrin (PLA), (2) 800 mg/day of calcium carbonate (Ca), and (3) 800 mg/day of calcium citrate and malate and 400 IU/day of vitamin D (Ca+D). Fasting blood samples, body composition, resting energy expenditure, aerobic capacity, muscular strength and endurance measures were assessed. Data were analyzed by mixed factorial ANOVA with repeated measures and presented as mean change from baseline [95% CI]. Exercise training promoted significant improvements in strength, peak aerobic capacity, and blood lipids. Dieting resulted in greater losses of body mass (CTL -0.4 ± 2.4; LCHC -5.1 ± 4.2; LCHP -3.8 ± 4.2 kg) and fat mass (CTL -1.4 ± 1.8; LCHC -3.7 ± 3.7; LCHP -3.4 ± 3.4 kg). When compared to LCHC-PLA, the LCHC + Ca combination led to greater losses in body mass (PLA -4.1 [-6.1, -2.1], Ca -6.4 [-8.1, -4.7], Ca+D -4.4 [-6.4, -2.5] kg). In comparison to LCHC-Ca, the LCHC-Ca+D led to an improved maintenance of fat-free mass (PLA -0.3 [-1.4, 0.7], Ca -1.4 [-2.3, -0.5], Ca+D 0.4 [-0.6, 1.5] kg) and a greater loss of body fat (PLA -2.3 [-3.4, -1.1], Ca -1.3 [-2.3, -0.3], Ca+D -3.6 [-4.8, -2.5]%). Alternatively, no significant differences in weight loss or body composition resulted when adding Ca or Ca+D to the LCHP regimen in comparison to when PLA was added to the LCHP diet. When combined with an energy-restricted, higher carbohydrate diet, adding 800 mg of Ca carbonate stimulated greater body mass loss compared to when a PLA was added. Alternatively, adding Ca+D to the LCHC diet promoted greater% fat changes and attenuation of fat-free mass loss. Our results expand upon current literature regarding the impact of calcium supplementation with dieting and regular exercise. This data highlights that different forms of calcium in combination with an energy restricted, higher carbohydrate diet may trigger changes in body mass or body composition while no impact of calcium supplementation was observed when participants followed an energy restricted, higher protein diet.

Background: We previously reported that consuming a food bar (FB) containing whey protein and the plant fiber isomalto-oligosaccharides [IMO] had a lower glycemic (GI) but similar insulinemic response as a high GI carbohydrate. Therefore, we hypothesized that ingestion of this FB before, during, and following intense exercise would better maintain glucose homeostasis and performance while hastening recovery in comparison to the common practice of ingesting carbohydrate alone., Methods: Twelve resistance-trained males participated in an open label, randomized, counterbalanced, crossover trial with a 7-d washout period. Participants consumed a carbohydrate matched dextrose comparitor (CHO) or a FB containing 20 g of whey, 25 g of IMO, and 7 g of fat 30-min before, mid-way, and following intense exercise. Participants performed 11 resistance-exercises (3 sets of 10 repetitions at 70% of 1RM) followed by agility and sprint conditioning drills for time. Participants donated blood to assess catabolic and inflammatory markers, performed isokinetic strength tests, and rated perceptions of muscle soreness, hypoglycemia before, and following exercise and after 48 h of recovery. Data were analyzed using general linear models (GLM) for repeated measures and mean changes from baseline with 95% confidence intervals (CI) with a one-way analysis of variance. Data are reported as mean change from baseline with 95% CI., Results: GLM analysis demonstrated that blood glucose was significantly higher 30-min post-ingestion for CHO (3.1 [2.0, 4.3 mmol/L,] and FB (0.8 [0.2, 1.5, mmol/L, p = 0.001) while the post-exercise ratio of insulin to glucose was greater with FB (CHO 0.04 [0.00, 0.08], FB 0.11 [0.07, 0.15], p = 0.013, η 2  = 0.25). GLM analysis revealed no significant interaction effects between treatments in lifting volume of each resistance-exercise or total lifting volume. However, analysis of mean changes from baseline with 95% CI's revealed that leg press lifting volume (CHO -130.79 [- 235.02, - 26.55]; FB -7.94 [- 112.17, 96.30] kg, p = 0.09, η 2  = 0.12) and total lifting volume (CHO -198.26 [- 320.1, - 76.4], FB -81.7 [- 203.6, 40.1] kg, p = 0.175, η 2  = 0.08) from set 1 to 3 was significantly reduced for CHO, but not for the FB. No significant interaction effects were observed in ratings of muscle soreness. However, mean change analysis revealed that ratings of soreness of the distal vastus medialis significantly increased from baseline with CHO while being unchanged with FB (CHO 1.88 [0.60, 3.17]; FB 0.29 [- 0.99, 1.57] cm, p = 0.083, η 2  = 0.13). No significant GLM interaction or mean change analysis effects were seen between treatments in sprint performance, isokinetic strength, markers of catabolism, stress and sex hormones, or inflammatory markers., Conclusion: Pilot study results provide some evidence that ingestion of this FB can positively affect glucose homeostasis, help maintain workout performance, and lessen perceptions of muscle soreness., Trial Registration: clinicaltrials.gov, # NCT03704337 . Retrospectively registered 12, July 2018.

Background: Sports nutrition is a constantly evolving field with hundreds of research papers published annually. In the year 2017 alone, 2082 articles were published under the key words 'sport nutrition'. Consequently, staying current with the relevant literature is often difficult., Methods: This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in 2004 and updated in 2010. It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. As such, this paper provides an overview of: 1.) How ergogenic aids and dietary supplements are defined in terms of governmental regulation and oversight; 2.) How dietary supplements are legally regulated in the United States; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of nutritional approaches to augment skeletal muscle hypertrophy and the potential ergogenic value of various dietary and supplemental approaches., Conclusions: This updated review is to provide ISSN members and individuals interested in sports nutrition with information that can be implemented in educational, research or practical settings and serve as a foundational basis for determining the efficacy and safety of many common sport nutrition products and their ingredients.

In a double-blind, crossover, randomized and placebo-controlled trial; 28 men and women ingested a placebo (PLA), 3 g of creatine nitrate (CNL), and 6 g of creatine nitrate (CNH) for 6 days. Participants repeated the experiment with the alternate supplements after a 7-day washout. Hemodynamic responses to a postural challenge, fasting blood samples, and bench press, leg press, and cycling time trial performance and recovery were assessed. Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM). No significant differences were found among treatments for hemodynamic responses, clinical blood markers or self-reported side effects. After 5 days of supplementation, one repetition maximum (1RM) bench press improved significantly for CNH (mean change, 95% CI; 6.1 [3.5, 8.7] kg) but not PLA (0.7 [-1.6, 3.0] kg or CNL (2.0 [-0.9, 4.9] kg, CNH, p = 0.01). CNH participants also tended to experience an attenuated loss in 1RM strength during the recovery performance tests following supplementation on day 5 (PLA: -9.3 [-13.5, -5.0], CNL: -9.3 [-13.5, -5.1], CNH: -3.9 [-6.6, -1.2] kg, p = 0.07). After 5 days, pre-supplementation 1RM leg press values increased significantly, only with CNH (24.7 [8.8, 40.6] kg, but not PLA (13.9 [-15.7, 43.5] or CNL (14.6 [-0.5, 29.7]). Further, post-supplementation 1RM leg press recovery did not decrease significantly for CNH (-13.3 [-31.9, 5.3], but did for PLA (-30.5 [-53.4, -7.7] and CNL (-29.0 [-49.5, -8.4]). CNL treatment promoted an increase in bench press repetitions at 70% of 1RM during recovery on day 5 (PLA: 0.4 [-0.8, 1.6], CNL: 0.9 [0.35, 1.5], CNH: 0.5 [-0.2, 0.3], p = 0.56), greater leg press endurance prior to supplementation on day 5 (PLA: -0.2 [-1.6, 1.2], CNL: 0.9 [0.2, 1.6], CNH: 0.2 [-0.5, 0.9], p = 0.25) and greater leg press endurance during recovery on day 5 (PLA: -0.03 [-1.2, 1.1], CNL: 1.1 [0.3, 1.9], CNH: 0.4 [-0.4, 1.2], p = 0.23). Cycling time trial performance (4 km) was not affected. Results indicate that creatine nitrate supplementation, up to a 6 g dose, for 6 days, appears to be safe and provide some ergogenic benefit., Competing Interests: C.P.E. serves as a paid consultant for Nutrabolt and is a Research Associate in the ESNL. Further, he holds scientific consultancies with Naturally Slim (Dallas, TX, USA) and Catapult Health (Dallas, TX, USA). R.B.K. serves as a university approved scientific advisor for Nutrabolt. P.S.M. served as quality assurance supervisor in accordance to a conflict of interest management plan that was approved by the university’s research and compliance office, the internal review board, and office of grants and contracts and monitored by research compliance. Remaining investigators have no competing interests to declare. The results from this study do not constitute endorsement by the authors and/or the institution concerning the nutrients investigated.

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).

Background: The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p- synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety., Methods: In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p -synephrine (20 mg). Participants had heart rate (HR), blood pressure, resting energy expenditure (REE), 12-lead electrocardiograms (ECG), perceptions about readiness to perform, cognitive function (Stroop Color-Word test), bench and leg press performance (2 sets of 10 repetitions at 70% of 1RM and 1 set to failure), and Wingate anaerobic capacity (WAC) sprint performance determined as well as donated blood samples prior to and/or following exercise/supplementation. Data were analyzed by MANOVA with repeated measures as well as mean changes from baseline with 95% confidence intervals (CI)., Results: No clinically significant differences were observed among treatments in HR, blood pressure, ECG, or general clinical blood panels. There was evidence that PWS and PWS + S ingestion promoted greater changes in REE responses. Participants reported higher perception of optimism about performance and vigor and energy with PWS and PWS + S ingestion and there was evidence that PWS and PWS + S improved changes in cognitive function scores from baseline to a greater degree than PLA after 1 or 2 h. However, the scores in the PWS + S treatment did not exceed PLA or PWS responses at any data point. No statistically significant differences were observed among treatments in total bench press lifting volume, leg press lifting volume or WAC sprint performance., Conclusions: Within the confines of this study, ingestion of PWS and/or PWS + S prior to exercise appears to be well-tolerated when consumed by young, healthy individuals. The primary effects appear to be to increase REE responses and improve perceptions about readiness to perform and cognitive function with limited to no effects on muscular endurance and WAC. The addition of 20 mg of p -synephrine to the PWS provided limited to no additive benefits., Trial Registration: This trial (NCT02952014) was retrospectively registered on September 13th 2016.

Background: The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males., Methods: Resistance-trained males ( N  = 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement with Citrus aurantium extract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training. Participants donated a fasting blood sample and had body composition (DXA), resting heart rate and blood pressure, cognitive function (Stroop Test), readiness to perform, bench and leg press 1 RM, and Wingate anaerobic capacity assessments determined a 0, 4, and 8-weeks of standardized training. Data were analyzed by MANOVA with repeated measures. Performance and cognitive function data were analyzed using baseline values as covariates as well as mean changes from baseline with 95% confidence intervals (CI). Blood chemistry data were also analyzed using Chi-square analysis., Results: Although significant time effects were seen, no statistically significant overall MANOVA Wilks' Lambda interactions were observed among groups for body composition, resting heart and blood pressure, readiness to perform questions, 1RM strength, anaerobic sprint capacity, or blood chemistry panels. MANOVA univariate analysis and analysis of changes from baseline with 95% CI revealed some evidence that cognitive function and 1RM strength were increased to a greater degree in the PWS and/or PWS + S groups after 4- and/or 8-weeks compared to PLA responses. However, there was no evidence that PWS + S promoted greater overall training adaptations compared to the PWS group. Dietary supplementation of PWS and PWS + S did not increase the incidence of reported side effects or significantly affect the number of blood values above clinical norms compared to PLA., Conclusion: Results provide some evidence that 4-weeks of PWS and/or PWS + S supplementation can improve some indices of cognitive function and exercise performance during resistance-training without significant side effects in apparently health males. However, these effects were similar to PLA responses after 8-weeks of supplementation and inclusion of synephrine did not promote additive benefits., Trial Registration: This trial (NCT02999581) was retrospectively registered on December 16th 2016.

Background: Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation., Methods: Study 1 participants (N = 13) ingested 1.5 g CrN (CrN-Low), 3 g CrN (CrN-High), 5 g CrM or a placebo in a randomized, crossover study (7d washout) to determine supplement safety (hepatorenal and muscle enzymes, heart rate, blood pressure and side effects) measured at time-0 (unsupplemented), 30-min, and then hourly for 5-h post-ingestion. Study 2 participants (N = 48) received the same CrN treatments vs. 3 g CrM in a randomized, double-blind, 28d trial inclusive of a 7-d interim testing period and loading sequence (4 servings/d). Day-7 and d-28 measured Tendo™ bench press performance, Wingate testing and a 6x6-s bicycle ergometer sprint. Data were analyzed using a GLM and results are reported as mean ± SD or mean change ± 95 % CI., Results: In both studies we observed several significant, yet stochastic changes in blood markers that were not indicative of potential harm or consistent for any treatment group. Equally, all treatment groups reported a similar number of minimal side effects. In Study 2, there was a significant increase in plasma nitrates for both CrN groups by d-7, subsequently abating by d-28. Muscle creatine increased significantly by d-7 in the CrM and CrN-High groups, but then decreased by d-28 for CrN-High. By d-28, there were significant increases in bench press lifting volume (kg) for all groups (PLA, 126.6, 95 % CI 26.3, 226.8; CrM, 194.1, 95 % CI 89.0, 299.2; CrN-Low, 118.3, 95 % CI 26.1, 210.5; CrN-High, 267.2, 95 % CI 175.0, 359.4, kg). Only the CrN-High group was significantly greater than PLA (p < 0.05). Similar findings were observed for bench press peak power (PLA, 59.0, 95 % CI 4.5, 113.4; CrM, 68.6, 95 % CI 11.4, 125.8; CrN-Low, 40.9, 95 % CI -9.2, 91.0; CrN-High, 60.9, 95 % CI 10.8, 111.1, W) and average power., Conclusions: Creatine nitrate delivered at 3 g was well-tolerated, demonstrated similar performance benefits to 3 g CrM, in addition, within the confines of this study, there were no safety concerns.

Background: The purpose of this study was to examine whether short-term ingestion of a powdered tart cherry supplement prior to and following intense resistance-exercise attenuates muscle soreness and recovery strength loss, while reducing markers of muscle damage, inflammation, and oxidative stress., Methods: Twenty-three healthy, resistance-trained men (20.9 ± 2.6 yr, 14.2 ± 5.4% body fat, 63.9 ± 8.6 kg FFM) were matched based on relative maximal back squat strength, age, body weight, and fat free mass. Subjects were randomly assigned to ingest, in a double blind manner, capsules containing a placebo (P, n = 12) or powdered tart cherries [CherryPURE(®)] (TC, n = 11). Participants supplemented one time daily (480 mg/d) for 10-d including day of exercise up to 48-h post-exercise. Subjects performed ten sets of ten repetitions at 70% of a 1-RM back squat exercise. Fasting blood samples, isokinetic MVCs, and quadriceps muscle soreness ratings were taken pre-lift, 60-min, 24-h, and 48-h post-lift and analyzed by MANOVA with repeated measures., Results: Muscle soreness perception in the vastus medialis (¼) (p = 0.10) and the vastus lateralis (¼) (p = 0.024) was lower in TC over time compared to P. Compared to pre-lift, TC vastus medialis (¼) soreness was significantly attenuated up to 48-h post-lift with vastus lateralis (¼) soreness significantly lower at 24-h post-lift compared to P. TC changes in serum creatinine (p = 0.03, delta p = 0.024) and total protein (p = 0.018, delta p = 0.006) were lower over time and smaller from pre-lift levels over time compared to P Significant TC group reductions from pre-lift levels were found for AST and creatinine 48-h post-lift, bilirubin and ALT 60-min and 48-h post-lift. No significant supplementation effects were observed for serum inflammatory or anti-inflammatory markers. None of the free radical production, lipid peroxidation, or antioxidant capacity markers (NT, TBARS, TAS, SOD) demonstrated significant changes with supplementation. Changes in TC whole blood lymphocyte counts (p = 0.013) from pre-lift were greater compared to P, but TC lymphocyte counts returned to pre-lift values quicker than P., Conclusion: Short-term supplementation of Montmorency powdered tart cherries surrounding a single bout of resistance exercise, appears to be an effective dietary supplement to attenuate muscle soreness, strength decrement during recovery, and markers of muscle catabolism in resistance trained individuals.

Coingestion of D-pinitol with creatine (CR) has been reported to enhance creatine uptake. The purpose of this study was to evaluate whether adding D-pinitol to CR affects training adaptations, body composition, whole-body creatine retention, and/or blood safety markers when compared to CR ingestion alone after 4 weeks of resistance training. Twenty-four resistance trained males were randomly assigned in a double-blind manner to creatine + pinitol (CRP) or creatine monohydrate (CR) prior to beginning a supervised 4-week resistance training program. Subjects ingested a typical loading phase (i.e., 20 g/d-1 for 5 days) before ingesting 5 g/d-1 the remaining 23 days. Performance measures were assessed at baseline (T0), week 1 (T1), and week 4 (T2) and included 1 repetition maximum (1RM) bench press (BP), 1RM leg press (LP), isokinetic knee extension, and a 30-second Wingate anaerobic capacity test. Fasting blood and body composition using dual-energy x-ray absorptiometry (DEXA) were determined at T1 and T3. Data were analyzed by repeated measures analysis of variance (ANOVA). Creatine retention increased (p < 0.001) in both groups as a result of supplementation but was not different between groups (p > 0.05). Significant improvements in upper- and lower-body strength and body composition occurred in both groups. However, significantly greater increases in lean mass and fat-free mass occurred in the CR group when compared to CRP (p <0.05). Adding D-pinitol to creatine monohydrate does not appear to facilitate further physiological adaptations while resistance training. Creatine monohydrate supplementation helps to improve strength and body composition while resistance training. Data from this study assist in determining the potential role the addition of D-pinitol to creatine may aid in facilitating training adaptations to exercise.

The purpose of this study was to examine the effects of whey protein supplementation on body composition, muscular strength, muscular endurance, and anaerobic capacity during 10 weeks of resistance training. Thirty-six resistance-trained males (31.0 +/- 8.0 years, 179.1 +/- 8.0 cm, 84.0 +/- 12.9 kg, 17.8 +/- 6.6%) followed a 4 days-per-week split body part resistance training program for 10 weeks. Three groups of supplements were randomly assigned, prior to the beginning of the exercise program, in a double-blind manner to all subjects: 48 g per day (g.d(-1)) carbohydrate placebo (P), 40 g.d(-1) of whey protein + 8 g.d(-1) of casein (WC), or 40 g.d(-1) of whey protein + 3 g.d(-1) branched-chain amino acids + 5 g.d(-1) L-glutamine (WBG). At 0, 5, and 10 weeks, subjects were tested for fasting blood samples, body mass, body composition using dual-energy x-ray absorptiometry (DEXA), 1 repetition maximum (1RM) bench and leg press, 80% 1RM maximal repetitions to fatigue for bench press and leg press, and 30-second Wingate anaerobic capacity tests. No changes (p > 0.05) were noted in all groups for energy intake, training volume, blood parameters, and anaerobic capacity. WC experienced the greatest increases in DEXA lean mass (P = 0.0 +/- 0.9; WC = 1.9 +/- 0.6; WBG = -0.1 +/- 0.3 kg, p < 0.05) and DEXA fat-free mass (P = 0.1 +/- 1.0; WC = 1.8 +/- 0.6; WBG = -0.1 +/- 0.2 kg, p < 0.05). Significant increases in 1RM bench press and leg press were observed in all groups after 10 weeks. In this study, the combination of whey and casein protein promoted the greatest increases in fat-free mass after 10 weeks of heavy resistance training. Athletes, coaches, and nutritionists can use these findings to increase fat-free mass and to improve body composition during resistance training.

Objective: We evaluated the effects of calcium pyruvate supplementation during training on body composition and metabolic responses to exercise., Methods: Twenty-three untrained females were matched and assigned to ingest in a double blind and randomized manner either 5 g of calcium pyruvate (PYR) or a placebo (PL) twice daily for 30 d while participating in a supervised exercise program. Prior to and following supplementation, subjects had body composition determined via hydrodensiometry; performed a maximal cardiopulmonary exercise test; and performed a 45-min walk test at 70% of pre-training VO2 max in which fasting pre- and post exercise blood samples determined., Results: No significant differences were observed between groups in energy intake or training volume. Univariate repeated measures ANOVA revealed that subjects in the PYR group gained less weight (PL 1.2 +/- 0.3, PYR 0.3 +/- 0.3 kg, P = 0.04), lost more fat (PL 1.1 +/- 0.5; PYR -0.4 +/- 0.5 kg, P = 0.03), and tended to lose a greater percentage of body fat (PL 1.0 +/- 0.7; PYR -0.65 +/- 0.6%, P = 0.07), with no differences observed in fat-free mass (PL 0.1 +/- 0.5; PYR 0.7 +/- 0.3 kg, P = 0.29). However, these changes were not significant when body composition data were analyzed by MANOVA (P = 0.16). There was some evidence that PYR may negate some of the beneficial effects of exercise on HDL values. No significant differences were observed between groups in maximal exercise responses or metabolic responses to submaximal walking., Conclusions: Results indicate that PYR supplementation during training does not significantly affect body composition or exercise performance and may negatively affect some blood lipid levels.

Creatine has become a popular nutritional supplement among athletes. Recent research has also suggested that there may be a number of potential therapeutic uses of creatine. This paper reviews the available research that has examined the potential ergogenic value of creatine supplementation on exercise performance and training adaptations. Review of the literature indicates that over 500 research studies have evaluated the effects of creatine supplementation on muscle physiology and/or exercise capacity in healthy, trained, and various diseased populations. Short-term creatine supplementation (e.g. 20 g/day for 5-7 days) has typically been reported to increase total creatine content by 10-30% and phosphocreatine stores by 10-40%. Of the approximately 300 studies that have evaluated the potential ergogenic value of creatine supplementation, about 70% of these studies report statistically significant results while remaining studies generally report non-significant gains in performance. No study reports a statistically significant ergolytic effect. For example, short-term creatine supplementation has been reported to improve maximal power/strength (5-15%), work performed during sets of maximal effort muscle contractions (5-15%), single-effort sprint performance (1-5%), and work performed during repetitive sprint performance (5-15%). Moreover, creatine supplementation during training has been reported to promote significantly greater gains in strength, fat free mass, and performance primarily of high intensity exercise tasks. Although not all studies report significant results, the preponderance of scientific evidence indicates that creatine supplementation appears to be a generally effective nutritional ergogenic aid for a variety of exercise tasks in a number of athletic and clinical populations.

Creatine has been reported to be an effective ergogenic aid for athletes. However, concerns have been raised regarding the long-term safety of creatine supplementation. This study examined the effects of long-term creatine supplementation on a 69-item panel of serum, whole blood, and urinary markers of clinical health status in athletes. Over a 21-month period, 98 Division IA college football players were administered in an open label manner creatine or non-creatine containing supplements following training sessions. Subjects who ingested creatine were administered 15.75 g/day of creatine monohydrate for 5 days and an average of 5 g/day thereafter in 5-10 g/day doses. Fasting blood and 24-h urine samples were collected at 0, 1, 1.5, 4, 6, 10, 12, 17, and 21 months of training. A comprehensive quantitative clinical chemistry panel was determined on serum and whole blood samples (metabolic markers, muscle and liver enzymes, electrolytes, lipid profiles, hematological markers, and lymphocytes). In addition, urine samples were quantitatively and qualitative analyzed to assess clinical status and renal function. At the end of the study, subjects were categorized into groups that did not take creatine (n = 44) and subjects who took creatine for 0-6 months (mean 4.4 +/- 1.8 months, n = 12), 7-12 months (mean 9.3 +/- 2.0 months, n = 25), and 12-21 months (mean 19.3 +/- 2.4 months, n = 17). Baseline and the subjects' final blood and urine samples were analyzed by MANOVA and 2 x 2 repeated measures ANOVA univariate tests. MANOVA revealed no significant differences (p = 0.51) among groups in the 54-item panel of quantitative blood and urine markers assessed. Univariate analysis revealed no clinically significant interactions among groups in markers of clinical status. In addition, no apparent differences were observed among groups in the 15-item panel of qualitative urine markers. Results indicate that long-term creatine supplementation (up to 21-months) does not appear to adversely effect markers of health status in athletes undergoing intense training in comparison to athletes who do not take creatine.

The purpose of this study was to examine the effects of creatine supplementation on the incidence of injury observed during 3-years of NCAA Division IA college football training and competition. In an open label manner, athletes participating in the 1998-2000 football seasons elected to take creatine or non-creatine containing supplements following workouts/practices. Subjects who decided to take creatine were administered 15.75 g of creatine for 5 days followed by ingesting an average of 5 g/day thereafter administered in 5-10 g doses. Creatine intake was monitored and recorded by research assistants throughout the study and ranged between 34-56% of players during the course of the study. Subjects practiced or played in environmental conditions ranging from 8-40 degrees C (mean 24.7 +/- 9 degrees C) and 19-98% relative humidity (49.3 +/- 17%). Injuries treated by the athletic training staff were recorded and categorized as cramping, heat/dehydration, muscle tightness, muscle strains/pulls, noncontact joint injuries, contact injuries, and illness. The number of missed practices due to injury/illness was also recorded. Data are presented as the total number of treated injuries for creatine users/total injuries observed and percentage occurrence rate of injuries for creatine users for all seasons. The incidence of cramping (37/96, 39%), heat/dehydration (8/28, 36%), muscle tightness (18/42, 43%), muscle pulls/strains (25/51, 49%), non-contact joint injuries (44/132, 33%), contact injuries (39/104, 44%), illness (12/27, 44%), number of missed practices due to injury (19/41, 46%), players lost for the season (3/8, 38%), and total injuries/missed practices (205/529, 39%) were generally lower or proportional to the creatine use rate among players. Creatine supplementation does not appear to increase the incidence of injury or cramping in Division IA college football players.

Conjugated linoleic acids (CLA) are essential fatty acids that have been reported in animal studies to decrease catabolism, promote fat loss, increase bone density, enhance immunity, and serve as an antiatherogenic and anticarcinogenic agent. For this reason, CLA has been marketed as a supplement to promote weight loss and general health. CLA has also been heavily marketed to resistance-trained athletes as a supplement that may help lessen catabolism, decrease body fat, and promote greater gains in strength and muscle mass during training. Although basic research is promising, few studies have examined whether CLA supplementation during training enhances training adaptations and/or affects markers of health. This study evaluated whether CLA supplementation during resistance training affects body composition, strength, and/or general markers of catabolism and immunity. In a double-blind and randomized manner, 23 experienced, resistance-trained subjects were matched according to body mass and training volume and randomly assigned to supplement their diet with 9 g;pdd(-1) of an olive oil placebo or 6 g;pdd(-1) of CLA with 3 g;pdd(-1) of fatty acids for 28 days. Prior to and following supplementation, fasting blood samples, total body mass, and dual-energy X-ray absorptiometry (DEXA) determined body composition, and isotonic bench press and leg press 1 repetition maximums (1RMs) were determined. Results revealed that although some statistical trends were observed with moderate to large effect sizes, CLA supplementation did not significantly affect (p > 0.05) changes in total body mass, fat-free mass, fat mass, percent body fat, bone mass, strength, serum substrates, or general markers of catabolism and immunity during training. These findings indicate that CLA does not appear to possess significant ergogenic value for experienced resistance-trained athletes.

BACKGROUND: 2-Fucosyllactose (2-FL) is an oligosaccharide contained in human milk and possesses prebiotic and anti-inflammatory effects, which may alleviate skeletal muscle atrophy under caloric restriction. This study evaluated the impacts of 12 weeks of 2-FL supplementation in conjunction with exercise (10,000 steps/day, 5 days/week) and energy-reduced (-300 kcals/day) dietary interventions on changes in body composition and health-related biomarkers. METHODS: A total of 41 overweight and sedentary female and male participants (38.0 ± 13 years, 90.1 ± 15 kg, 31.6 ± 6.6 kg/m2, 36.9 ± 7% fat) took part in a randomized, double-blind, and placebo-controlled study. The participants underwent baseline assessments and were then assigned to ingest 3 g/day of a placebo (PLA) or Momstamin 2-F while initiating the exercise and weight-loss program. Follow-up tests were performed after 6 and 12 weeks. Data were analyzed using general linear model statistics with repeated measures and mean changes from baseline values with 95% confidence intervals (CIs). RESULTS: No group × time × sex interaction effects were observed, so group × time effects are reported. Participants in both groups saw comparable reductions in weight. However, those with 2-FL demonstrated a significantly greater reduction in the percentage of body fat and less loss of the fat-free mass. Additionally, there was evidence that 2-FL supplementation promoted more favorable changes in resting fat oxidation, peak aerobic capacity, IL-4, and platelet aggregation, with some minimal effects on the fermentation of short-chain fatty acids and monosaccharides in fecal samples. Moreover, participants perceptions regarding some aspects of the functional capacity and ratings of the quality of life were improved, and the supplementation protocol was well tolerated, although a small, but significant, decrease in BMC was observed. CONCLUSIONS: The results support contentions that dietary supplementation of 2-FL (3 g/d) can promote fat loss and improve exercise- and diet-related markers of health and fitness in overweight sedentary individuals initiating an exercise and weight-loss program. Further research is needed to explore the potential health benefits of 2-FL supplementation in both healthy and elderly individuals (Registered clinical trial #NCT06547801).

The editorial discusses the intersection of sports medicine, nutritional sciences, and nutritional biochemistry, focusing on the use of nutritional supplements in sports performance and health. Various studies highlighted the importance of balanced nutrition, physical activity, and tailored nutrition strategies in supporting athletes' mental and physical well-being. The article also addresses the risks associated with dietary supplements, emphasizing the need for rigorous quality control measures and scientific evidence-based practices to ensure safety and efficacy in supplement use. [Extracted from the article]

The purpose was to investigate the effects of CYPjA2 -163(> A polymorphism on the effects of acute caffeine (CAF) supplementation on anaerobic power in trained males. Sixteen trained males (age: 21.6 + 7.1 years; height: 179.7 + 5.6 cm; body mass: 72.15 + 6.8 kg) participated in a randomized, double-blind, placebo (PLA) controlled crossover design. Participants supplemented with CAF (6 mg/kg of body mass) and an isovolumetric PLA (maltodextrin) in random order and separated by 7 days, before an all-out 30-s anaerobic cycling test to determine peak, average, and minimum power output, and fatigue index. Genomic deoxyribonucleic acid was extracted to identify each participants CYPJA2 genotype. Six participants expressed AA homozygote and 10 expressed C alleles. There was a treatment by genotype interaction for peak power output (p =.041, 112 =.265, observed power = 0.552) with only those expressing AA genotype showing improvement following CAF supplementation compared with PLA (CAF: 693 + 108 watts vs. PLA: 655 * 97 watts; p =.039), while no difference between treatments was noted in those expressing C alleles (CAF: 614 + 92 watts vs. PLA: 659 + 144 watts;p =.135). There were no other interaction or main effects for average or minimum power output, or fatigue index (p > .05). In conclusion, the ingestion of 6 mg/kg of CAF improved peak power output only in participants with the AA genotype compared with PLA; however, expression of the CYPh42 did not influence average or minimum power output or fatigue index [ABSTRACT FROM AUTHOR]

It is estimated that three to five million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly affectation of the musculoskeletal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to perform an update on nutritional strategies during the rehabilitation phase of musculoskeletal injuries in elite athletes. After searching the following databases: PubMed/Medline, Scopus, PEDro, and Google Scholar, a total of 18 studies met the inclusion criteria (Price Index: 66.6%). The risk of bias assessment for randomized controlled trials was performed using the RoB 2.0 tool while review articles were evaluated using the AMSTAR 2.0 items. Based on the main findings of the selected studies, nutritional strategies that benefit the rehabilitation process in injured athletes include balanced energy intake, and a high-protein and carbohydrate-rich diet. Supportive supervision should be provided to avoid low energy availability. The potential of supplementation with collagen, creatine monohydrate, omega-3 (fish oils), and vitamin D requires further research although the effects are quite promising. It is worth noting the lack of clinical research in injured athletes and the higher number of reviews in the last 10 years. After analyzing the current quantitative and non-quantitative evidence, we encourage researchers to conduct further clinical research studies evaluating doses of the discussed nutrients during the rehabilitation process to confirm findings, but also follow international guidelines at the time to review scientific literature. [ABSTRACT FROM AUTHOR]

Abstract Sport nutrition is a constantly evolving field with literally thousands of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper presents a well-referenced overview of the current state of the science related to how to optimize training through nutrition. More specifically, this article discusses: 1.) how to evaluate the scientific merit of nutritional supplements; 2.) general nutritional strategies to optimize performance and enhance recovery; and, 3.) our current understanding of the available science behind weight gain, weight loss, and performance enhancement supplements. Our hope is that ISSN members find this review useful in their daily practice and consultation with their clients.

This study examined whether adding Dichrostachys glomerata (DG; 300 mg/d) to thermogenic supplements with (DG + C) and without (DG) caffeine and other nutrients affects weight loss, changes in body composition, and/or markers of health. Sixty-eight participants (female, 54%) were grouped in a double-blind, parallel, stratified random, placebo-controlled manner to supplement their diet with a placebo, DG, or DG + C for 12 weeks while maintaining their normal diet and physical activity. Diet, physical activity, body weight, body composition, anthropometric measures, resting energy expenditure, fasting blood samples, and questionnaires were obtained at 0, 4, 8, and 12 weeks and analyzed using general linear models with repeated measures. Data are reported as mean (±SD) and change from baseline (mean, 95% confidence interval) for weeks 4, 8, and 12, respectively, with p values showing changes from baseline. DG treatment promoted significant but minor reductions in fat mass (−0.56 [−1.02, −0.14], p = 0.01; −0.63 [−1.23, −0.02], p = 0.04; −0.71 [−1.47, 0.09] kg, p = 0.08) and percent body fat (−0.46 [−0.96, −0.04], p = 0.07; −0.63 [−1.16, −0.10], p = 0.02; −0.78 [−1.45, 0.07] %, p = 0.03). There was some evidence that DG + C increased resting energy expenditure, decreased hunger, increased satiety, and improved sleep quality (diminished in DG + C). No other significant effects were observed. Ingestion of thermogenic supplements containing DG (300 mg/d) with and without caffeine and other nutrients in overweight but otherwise healthy participants who did not alter diet or physical activity promoted clinically insignificant changes in body weight and composition. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of an alleged aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum ( 1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05). Significant Group x Time interaction effects occurred over the 8-wk period for percent body fat (AI: -1.77% ± 1.52%, PL: -0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: -2.10 ± 3.75 ng/ml;p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: -1.69 ± 3.94 ng/ml; p = .049). Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05). The authors concluded that 500 mg of daily AI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p-synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety. Methods: In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p-synephrine (20 mg). Participants had heart rate (HR), blood pressure, resting energy expenditure (REE), 12-lead electrocardiograms (ECG), perceptions about readiness to perform, cognitive function (Stroop Color-Word test), bench and leg press performance (2 sets of 10 repetitions at 70% of 1RM and 1 set to failure), and Wingate anaerobic capacity (WAC) sprint performance determined as well as donated blood samples prior to and/or following exercise/supplementation. Data were analyzed by MANOVA with repeated measures as well as mean changes from baseline with 95% confidence intervals (CI). Results: No clinically significant differences were observed among treatments in HR, blood pressure, ECG, or general clinical blood panels. There was evidence that PWS and PWS + S ingestion promoted greater changes in REE responses. Participants reported higher perception of optimism about performance and vigor and energy with PWS and PWS + S ingestion and there was evidence that PWS and PWS + S improved changes in cognitive function scores from baseline to a greater degree than PLA after 1 or 2 h. However, the scores in the PWS + S treatment did not exceed PLA or PWS responses at any data point. No statistically significant differences were observed among treatments in total bench press lifting volume, leg press lifting volume or WAC sprint performance. Conclusions: Within the confines of this study, ingestion of PWS and/or PWS + S prior to exercise appears to be well-tolerated when consumed by young, healthy individuals. The primary effects appear to be to increase REE responses and improve perceptions about readiness to perform and cognitive function with limited to no effects on muscular endurance and WAC. The addition of 20 mg of p-synephrine to the PWS provided limited to no additive benefits. Trial registration: This trial (NCT02952014) was retrospectively registered on September 13th 2016. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to determine whether short-term supplementation of a powdered tart cherry supplement prior to and following stressful endurance exercise would affect markers of muscle damage, inflammation, oxidative stress, and/or muscle soreness. Methods: 27 endurance-trained runners or triathlete (21.8 ± 3.9 years, 15.0 ± 6.0 % body fat, 67.4 ± 11.8 kg) men (n =18) and women (n = 9) were matched based on average reported race pace, age, body mass, and fat free mass. Subjects were randomly assigned to ingest, in a double-blind manner, capsules containing 480 mg of a rice flour placebo (P, n = 16) or powdered tart cherries [CherryPURE®] (TC, n = 11). Subjects supplemented one time daily (480 mg/day) for 10-d, including race day, up to 48-hr post-run. Subjects completed a half-marathon run (21.1 km) under 2-hr (111.98 ± 11. 9 min). Fasting blood samples and quadriceps muscle soreness ratings using an algometer with a graphic pain rating scale were taken pre-run, 60-min, 24 and 48-h post-run and analyzed by MANOVA with repeated measures. Results: Subjects in the TC group averaged 13 % faster half-marathon race finish times (p = 0.001) and tended to have smaller deviations from predicted race pace (p = 0.091) compared to P. Attenuations in TC muscle catabolic markers were reported over time for creatinine (p = 0.047), urea/blood urea nitrogen (p = 0.048), total protein (p = 0.081), and cortisol (p = 0.016) compared to P. Despite lower antioxidant activity pre-run in TC compared to P, changes from pre-run levels revealed a linear increase in antioxidant activity at 24 and 48-h of recovery in TC that was statistically different (16–39 %) from P and pre-run levels. Inflammatory markers were 47 % lower in TC compared to P over time (p = 0.053) coupled with a significant difference between groups (p = 0.017). Soreness perception between the groups was different over time in the medial quadriceps (p = 0.035) with 34 % lower pre-run soreness in TC compared to P. Over the 48-h recovery period, P changes in medial quadriceps soreness from pre-run measures were smaller compared to TC. Conclusion: Results revealed that short-term supplementation of Montmorency powdered tart cherries surrounding an endurance challenge attenuated markers of muscle catabolism, reduced immune and inflammatory stress, better maintained redox balance, and increased performance in aerobically trained individuals. [ABSTRACT FROM AUTHOR]

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 carnosine concentrations, thereby acting as an intracellular pH buffer; 2) Beta-alanine supplementation currently appears to be safe in healthy populations at recommended doses; 3) The only reported side effect is paraesthesia (tingling), but studies indicate this can be attenuated by using divided lower doses (1.6 g) or using a sustained-release formula; 4) Daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration; 5) Beta-alanine attenuates neuromuscular fatigue, particularly in older subjects, and preliminary evidence indicates that beta-alanine may improve tactical performance; 6) Combining beta-alanine with other single or multi-ingredient supplements may be advantageous when supplementation of beta-alanine is high enough (4–6 g daily) and long enough (minimum 4 weeks); 7) More research is needed to determine the effects of beta-alanine on strength, endurance performance beyond 25 min in duration, and other health-related benefits associated with carnosine. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to examine the short-term and chronic effects of β-ALA supplementation with and without creatine monohydrate on body composition, aerobic and anaerobic exercise performance, and muscle carnosine and creatine levels in college-aged recreationally active females. Methods: Thirty-two females were randomized in a double-blind, placebo-controlled manner into one of four supplementation groups: β-ALA only (BA, n = 8), creatine only (CRE, n = 8), β-ALA and creatine combined (BAC, n = 9) and placebo (PLA, n = 7). Participants supplemented for four weeks included a loading phase for the creatine for week 1 of 0.3 g/kg of body weight and a maintenance phase for weeks 2–4 of 0.1 g/kg of body weight, with or without a continuous dose of β-ALA of 0.1 g/kg of body weight with doses rounded to the nearest 800 mg capsule providing an average of 6.1 ± 0.7 g/day of β-ALA. Participants reported for testing at baseline, day 7 and day 28. Testing sessions consisted of obtaining a resting muscle biopsy of the vastus lateralis, body composition measurements, performing a graded exercise test on the cycle ergometer for VO2peak with lactate threshold determination, and multiple Wingate anaerobic capacity tests. Results: Although mean changes were consistent with prior studies and large effect sizes were noted, no significant differences were observed among groups in changes in muscle carnosine levels (BA 35.3 ± 45; BAC 42.5 ± 99; CRE 0.72 ± 27; PLA 13.9 ± 44%, p = 0.59). Similarly, although changes in muscle phosphagen levels after one week of supplementation were consistent with prior reports and large effect sizes were seen, no statistically significant effects were observed among groups in changes in muscle phosphagen levels and the impact of CRE supplementation appeared to diminish during the maintenance phase. Additionally, significant time × group × Wingate interactions were observed among groups for repeated sprint peak power normalized to bodyweight (p = 0.02) and rate of fatigue (p = 0.04). Conclusions: Results of the present study did not reveal any consistent additive benefits of BA and CRE supplementation in recreationally active women. [ABSTRACT FROM AUTHOR]

Background: Extracts of Russian Tarragon (RT) have been reported to produce anti-hyperglycemic effects and influence plasma creatine (Cr) levels while supplementing with creatine monohydrate (CrM). The purpose of this preliminary study was to determine if short-term, low-dose aqueous RT extract ingestion prior to CrM supplementation influences whole body Cr retention, muscle Cr or measures of anaerobic sprint performance. Methods: In a double-blind, randomized, and crossover manner; 10 recreationally trained males (20 ± 2 yrs; 179 ± 9 cm; 91.3 ± 34 kg) ingested 500 mg of aqueous RT extract (Finzelberg, Andernach, Germany) or 500 mg placebo 30-minutes prior to ingesting 5 g of CrM (Creapure®, AlzChem AG, Germany) twice per day for 5-days then repeated after a 6-week wash-out period. Urine was collected at baseline and during each of the 5-days of supplementation to determine urine Cr content. Whole body Cr retention was estimated from urine samples. Muscle biopsies were obtained for determination of muscle free Cr content. Participants also performed two 30-second Wingate anaerobic capacity tests prior to and following supplementation for determination of peak power (PP), mean power (MP), and total work (TW). Data were analysed by repeated measures MANOVA. Results: Whole body daily Cr retention increased in both groups following supplementation (0.0 ± 0.0; 8.2 ± 1.4, 6.5 ± 2.4, 5.6 ± 3.2, 6.1 ± 2.6, 4.8 ± 3.2 g · d-1; p = 0.001) with no differences observed between groups (p = 0.59). After 3 and 5-days of supplementation, respectively, both supplementation protocols demonstrated a significant increase in muscle free Cr content from baseline (4.8 ± 16.7, 15.5 ± 23.6 mmol · kg-1 DW, p = 0.01) with no significant differences observed between groups (p = 0.34). Absolute change in MP (9 ± 57, 35 ± 57 W; p = 0.031), percent change in MP (2.5 ± 10.5, 6.7 ± 10.4%; p = 0.026), absolute change in TW (275 ± 1,700, 1,031 ± 1,721 J; p = 0.032), and percent change in TW (2.5 ± 10.5, 6.6 ± 10.4%; p = 0.027) increased over time in both groups with no differences observed between groups. Conclusions: Short-term CrM supplementation (10 g · d-1 for 5-days) significantly increased whole body Cr retention and muscle free Cr content. However, ingesting 500 mg of RT 30-min prior to CrM supplementation did not affect whole body Cr retention, muscle free Cr content, or anaerobic sprint capacity in comparison to ingesting CrM with a placebo. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to determine whether sedentary obese women with knee OA initiating an exercise and weight loss program may experience more beneficial changes in body composition, functional capacity, and/or markers of health following a higher protein diet compared to a higher carbohydrate diet with or without GCM supplementation. Methods: Thirty sedentary women (54 ± 9 yrs, 163 ± 6 cm, 88.6 ± 13 kg, 46.1 ± 3% fat, 33.3 ± 5 kg/m²) with clinically diagnosed knee OA participated in a 14-week exercise and weight loss program. Participants followed an isoenergenic low fat higher carbohydrate (HC) or higher protein (HP) diet while participating in a supervised 30- minute circuit resistance-training program three times per week for 14-weeks. In a randomized and double blind manner, participants ingested supplements containing 1,500 mg/d of glucosamine (as d-glucosamine HCL), 1,200 mg/d of chondroitin sulfate (from chondroitin sulfate sodium), and 900 mg/d of methylsulfonylmethane or a placebo. At 0, 10, and 14-weeks, participants completed a battery of assessments. Data were analyzed by MANOVA with repeated measures. Results: Participants in both groups experienced significant reductions in body mass (-2.4 ± 3%), fat mass (-6.0 ± 6%), and body fat (-3.5 ± 4%) with no significant changes in fat free mass or resting energy expenditure. Perception of knee pain (-49 ± 39%) and knee stiffness (-42 ± 37%) was decreased while maximal strength (12%), muscular endurance (20%), balance indices (7% to 20%), lipid levels (-8% to -12%), homeostasis model assessment for estimating insulin resistance (-17%), leptin (-30%), and measures of physical functioning (59%), vitality (120%), and social function (66%) were improved in both groups with no differences among groups. Functional aerobic capacity was increased to a greater degree for those in the HP and GCM groups while there were some trends suggesting that supplementation affected perceptions of knee pain (p < 0.08). Conclusions: Circuit style resistance-training and weight loss improved functional capacity in women with knee OA. The type of diet and dietary supplementation of GCM provided marginal additive benefits. [ABSTRACT FROM AUTHOR]

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients. [ABSTRACT FROM AUTHOR]

Previous research has indicated that creatine retention is influenced by intramuscular creatine concentration and extracellular concentrations of glucose and insulin. This study examined whether different nutritional strategies affect whole body creatine retention. Specifically, 16 males with no history of creatine supplementation participated in this study. Subjects donated 24-hr urine samples for 4 days. After an initial control day, subjects were matched according to body mass and assigned to ingest in a single blind manner either 5 g of dextrose (D), 5 g of creatine monohydrate (CM), 5 g of CM + 18 g dextrose (C+D), or an effervescent creatine (EC) supplement (5 g of creatine + 18 g dextrose + 320 mg of sodium [as sodium carbonate and bicarbonate] + 175 mg of potassium [as potassium bicarbonate]) four times/day for 3 days. Creatine retention was estimated by subtracting total urinary creatine excretion from total supplemental creatine intake over the 3 day period. Data were analyzed by ANOVA. Results revealed that creatine retention was increased following creatine supplementation in all groups (D=0±0; CM= 36.6±9; C+D=48.0±7; EC=37.8±8 g, p=0.001). However, creatine retention in the C+D group was significantly greater than the CM group while no differences were observed between the EC and CM groups. This resulted in a greater percentage of creatine retention in the CD group (D= 0±0; CM=61±15; C+D=80±11; EC=63±13 %, p=0.001). These preliminary findings suggest that in accordance with previous research, ingesting dextrose (18 g) with CM (5 g) augments whole body creatine retention while EC supplementation appears to be no more effective than ingesting CM alone. [ABSTRACT FROM AUTHOR]

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization. [ABSTRACT FROM AUTHOR]

Creatine monohydrate (CrM) supplementation has been shown to improve body composition and muscle strength when combined with resistance training (RT); however, no study has evaluated the combination of this nutritional strategy with cluster-set resistance training (CS-RT). The purpose of this pilot study was to evaluate the effects of CrM supplementation during a high-protein diet and a CS-RT program on lower-limb fat-free mass (LL-FFM) and muscular strength. Twenty-three resistance-trained men (>2 years of training experience, 26.6 ± 8.1 years, 176.3 ± 6.8 cm, 75.6 ± 8.9 kg) participated in this study. Subjects were randomly allocated to a CS-RT+CrM (n = 8), a CS-RT (n = 8), or a control group (n = 7). The CS-RT+CrM group followed a CrM supplementation protocol with 0.1 g·kg−1·day−1 over eight weeks. Two sessions per week of lower-limb CS-RT were performed. LL-FFM corrected for fat-free adipose tissue (dual-energy X-ray absorptiometry) and muscle strength (back squat 1 repetition maximum (SQ-1RM) and countermovement jump (CMJ)) were measured pre- and post-intervention. Significant improvements were found in whole-body fat mass, fat percentage, LL-fat mass, LL-FFM, and SQ-1RM in the CS-RT+CrM and CS-RT groups; however, larger effect sizes were obtained in the CS-RT+CrM group regarding whole body FFM (0.64 versus 0.16), lower-limb FFM (0.62 versus 0.18), and SQ-1RM (1.23 versus 0.75) when compared to the CS-RT group. CMJ showed a significant improvement in the CS-RT+CrM group with no significant changes in CS-RT or control groups. No significant differences were found between groups. Eight weeks of CrM supplementation plus a high-protein diet during a CS-RT program has a higher clinical meaningfulness on lower-limb body composition and strength-related variables in trained males than CS-RT alone. Further research might study the potential health and therapeutic effects of this nutrition and exercise strategy. [ABSTRACT FROM AUTHOR]

Creatine is one of the most popular supplements worldwide, and it is frequently used by both athletic and non-athletic populations to improve power, strength, muscle mass and performance. A growing body of evidence has been identified potential therapeutic effects of creatine in a wide variety of clinical conditions, such as cancer, muscle dystrophy and neurodegenerative disorders. Evidence has suggested that creatine supplementation alone, and mainly in combination with exercise training, may improve glucose metabolism in health individuals and insulin-resistant individuals, such as in those with type 2 diabetes mellitus. Creatine itself may stimulate insulin secretion in vitro, improve muscle glycogen stores and ameliorate hyperglycemia in animals. In addition, exercise induces numerous metabolic benefits, including increases in insulin-independent muscle glucose uptake and insulin sensitivity. It has been speculated that creatine supplementation combined with exercise training could result in additional improvements in glucose metabolism when compared with each intervention separately. The possible mechanism underlying the effects of combined exercise and creatine supplementation is an enhanced glucose transport into muscle cell by type 4 glucose transporter (GLUT-4) translocation to sarcolemma. Although preliminary findings from small-scale trials involving patients with type 2 diabetes mellitus are promising, the efficacy of creatine for improving glycemic control is yet to be confirmed. In this review, we aim to explore the possible therapeutic role of creatine supplementation on glucose management and as a potential anti-diabetic intervention, summarizing the current knowledge and highlighting the research gaps. [ABSTRACT FROM AUTHOR]