Marketable 1,3-dimethylamylamine and caffeine-based thermogenic supplements: Regulatory genotoxicity assessment through in vitro and in silico approaches.

The consumption of dietary supplements to enhance physical performance has increased significantly in the last century, especially thermogenic pre-workout supplements. Nevertheless, this industry has faced criticism for inadequate safety measures surveillance in regulatory issues regarding their products. The aims of our study were to investigate two pre-workout supplements with respect to (1) mutagenicity utilizing Salmonella/microsome assay; (2) genotoxicity employing cytokinesis-block micronucleus (CBMN) assay protocols; and (3) hepatocytoxicity using WST cell proliferation, activities of lactate dehydrogenase (LDH) and alkaline phosphatase using human liver carcinoma (HepG2) and mouse fibroblast (F C3H) cells. Oxidative stress was determined through glutathione (GSH) measurement and in silico for predictions of pharmacokinetics and toxicity for the most abundant isolated substances present in these supplements. Both supplements induced mutagenicity in all examined bacterial strains, especially in the presence of exogenous metabolism. Further, tested supplements significantly elevated the formation of micronuclei (MN) as well as other cellular phenomena. Concentration- and time-dependent curves were observed for hepatotoxicity in both studied cell lines. In addition, both supplements decreased levels of intracellular and extracellular GSH. In silico predictions showed that the isolated individual compounds failed to induce the observed outcomes. Our findings provide contributions to the molecular mechanisms underlying two pre-workout supplement-induced toxicity and the need for surveillance.

Analysis of the pH levels in energy and pre-workout beverages and frequency of consumption: a cross-sectional study.

BACKGROUND: Erosive tooth wear is an increasingly common pathology in the youth population. It refers to the chronic, localized, painless loss of dental hard tissues caused by non-bacterial acids, often originating from external sources like acidic beverages. Energy drink consumption is on the rise, frequently preceding physical exercise to enhance perceived energy levels. However, there are other types of beverages that also provide energy, such as pre-workout drinks, classified as sports drinks. The main objective of this research study has been conducted with the purpose of analyzing the pH of energy drinks and pre-workout beverages, and studying the frequency of consumption of such beverages in amateur athletes who practice sports. METHODS: A total of 67 beverages were examined, comprising 43 energy drinks and 24 sports supplementation beverages, also known as pre-workout or pre-training beverages. The participants were given a survey to complete. They were asked to respond whether they consumed any type of pre-workout or energy drink, and they were also asked about the timing of consumption. RESULTS: The findings indicated an average pH of 3.3 among the studied beverages, indicating a pH below the critical threshold. Out of the 113 participants, 51% reported taking some form of supplementation. CONCLUSIONS: Consequently, it was concluded that most of the analyzed beverages recorded pH values low enough to classify them as erosive, posing a threat to enamel surface. When analyzing the frequency of consumption of energy drinks and pre-workout beverages in amateur athletes, we observed that most participants aged 29 years or younger took supplements 3 to 5 times a week, while the older age groups more frequently took supplements 1 to 2 times a week.

PRE-WORKOUT SUPPLEMENT INDUCED CARDIAC ISCHAEMIA IN A YOUNG FEMALE.

The popularity of pre-workout supplements is rising amongst professional athletes and fitness enthusiasts. Despite increased usage, the safety profile of pre-workout supplements is likely to be not well understood. Additionally, many different brands use various undisclosed proprietary blends of active ingredients creating safety regulation difficulties. This lack of oversight could prove unsafe for certain patients. This patient MK is a 33-year-old healthy housewife who presented with central chest tightness, pre-syncope and mild dyspnoea to the emergency department via ambulance. The presentation was in the context of recent strenuous exercise and ingestion of a pre-workout supplement (Alpha Lean-7). Most striking in her presentation was a troponin rise of 50 ng/L, while not very high it is unusual given her lack of cardiac risk factors. She had a 3-day uneventful admission with a downtrending troponin prior to discharge. This case highlights the possible dangers of pharmacologically active ingredients in pre-workout supplements.

Comparison of GC-MS and MEKC methods for caffeine determination in preworkout supplements.

In this study, GC-MS- and MEKC-based methods for determination of caffeine (CAF) in preworkout supplements were developed and validated. The proposed protocols utilized minimal sample preparation (simple dilution and syringe filtration). The developed methods achieved satisfactory validation parameters, i.e. good linearity (R2 > 0.9988 and R2 > 0.9985 for GC-MS- and MEKC-based method, respectively), satisfactory intra- and interaccuracy (within 92.6-100.7% for method utilizing GC-MS and 92.1-110.3% for protocol based on MEKC) and precision (CV < 15.9% and CV < 6.3% for GC-MS- and MEKC-based method, respectively) and recovery (within 100.1-100.8% for method utilizing GC-MS and 101.5-106.2% for protocol based on MEKC). The LOD was 0.03 and 3 µg/mL for method utilizing GC-MS and MEKC, respectively. The CAF concentrations determined by GC-MS- and MEKC-based methods were found to be in the range of 8.53-11.23 and 8.20-11.61 µg/mL, respectively. Taking into consideration information on the labels, the investigated supplements were found to contain from 110.0 to 167.3% of the declared CAF content, which confirmed the literature reports on incompatibility of the declared product compositions with real ones. Nevertheless, the consumption of examined supplements as recommended by producers did not lead to exceeding the CAF safe limit of 400 mg per day. Additionally, the MEKC-based method allowed for detection and identification of vitamin B3 and B6 in all of the investigated supplement samples, which demonstrated that MEKC-based protocols may be an appropriate assays for simultaneous determination of CAF and vitamins.

A combination of oral L-citrulline and L-arginine improved 10-min full-power cycling test performance in male collegiate soccer players: a randomized crossover trial.

PURPOSE: Oral L-citrulline (Cit) increases plasma L-arginine (Arg) concentration and the production of nitric oxide (NO). NO dilates blood vessels and potentially improves sports performance. The combination of oral Arg and Cit (Arg + Cit) immediately and synergistically increases plasma Arg and nitrite/nitrate (NOx) concentrations more than either Cit or Arg alone. This prompted us to assess the effects of oral Arg + Cit on 10-min cycling performance in a double-blind, randomized, placebo-controlled crossover trial. METHODS: Twenty-four male soccer players ingested either Cit + Arg or placebo (both 1.2 g/day each) for 6 days. On day 7, they ingested Cit + Arg 1 h before performing a 10-min full-power pedaling test on a bicycle ergometer. Plasma NOx and amino acid levels were measured before and after the test, as well as the participants' subjective perception of physical exertion. RESULTS: Power output was significantly greater with Cit + Arg than in the placebo group (242 ± 24 vs. 231 ± 21 W; p < 0.05). Plasma concentrations of post-exercise NOx (p < 0.05), Cit (p < 0.01) and Arg (p < 0.01) were significantly higher in the Cit + Arg than in the placebo group, whereas exercise upregulated plasma NOx concentrations in both groups (p < 0.05). Cit + Arg also gave improved post-exercise subjective perception of "leg muscle soreness" and "ease of pedaling" (both p < 0.05). CONCLUSION: Seven days of oral Citrulline (1.2 g/d) and Arginine (1.2 g/d) ingestion improved 10-min cycling performance and the perception of physical exertion in male collegiate soccer players.

Effects of a pre-workout supplement on lean mass, muscular performance, subjective workout experience and biomarkers of safety.

In this prospective, randomized, double-blind, trial conducted in two parts, we examined the effects of a multi-ingredient pre-exercise workout supplement blend of creatine, betaine and a dendrobium extract (MMP) on safety, performance, and body composition in healthy men and women undergoing a supervised program of resistance exercise. Part 1 was an acute hemodynamic safety study wherein forty young, healthy men and women (26.2 ± 5.3 years, 70.4 ± 3.3 inches, 83.7 ± 14.9 kg, 26.0 ± 3.2 kg●m(-2)) ingest one dose of either the MMP or comparator in a randomized, double-blind, comparator controlled, crossover fashion before having their resting heart rate, blood, ECG and comprehensive blood chemistry and blood counts completed. Systolic (SBP) and diastolic (DBP) blood pressures were generally raised (3.0-5.4 mm Hg, p<0.01) following supplementation with MPP whereas in the comparator group SBP was marginally reduced by 0.3 to 1.2 mm Hg, p>0.05 at all time points) and DBP was increased (3.0 - 3.9 mm Hg, p<0.05 at all time points). No changes in EKG-corrected QT interval were observed, and no serious adverse events were reported. Part 2 was a six-week training study wherein forty-three young, healthy men and women (24.3 ± 2.9 years, 70.5 ± 3.1 inches, 83.8 ± 9.6 kg, 26.1 ± 2.7 kg●m(-2)) supplemented with daily pre-workout doses of either the MPP or a comparator in a randomized, double-blind, comparator-controlled fashion while following a standardized resistance training program for six weeks. MPP and the comparator were isocaloric and delivered the same amount of caffeine. Significant improvements in visual analog scale (VAS) scores for energy (p<0.024) and concentration (p<0.041) were found along with consistently higher levels of focus accompanied by less fatigue when MPP was consumed in comparison to comparator during upper body muscular strength-endurance tests at weeks 3 and 6. MPP supplementation for 6 weeks did not improve dual-energy x-ray absorptiometry (DEXA) measures of body composition or objective assessments of exercise performance. Overall, MPP use and administration was well tolerated. Self-reported scores for energy and concentration were significantly greater. Over a six-week training and supplementation period, MPP use was not associated with improvements in performance or body composition. Future studies should confirm these effects over a more prolonged training period.

Ten weeks of Capsicum annuum L. extract supplementation did not change adipose tissue-derived hormones, appetite, body composition, and muscle strength when combined with resistance training in healthy untrained men: A clinical trial study.

Capsiate (CAP) is a nonpungent capsaicin analog (Capsicum annuum L. extract) that has been studied as a potential antiobesity agent. However, the interaction between chronic CAP supplementation and resistance training is not clear. The purpose of this study was to examine the changes in adipose tissue-derived hormones, body composition, appetite, and muscle strength after 10 weeks of resistance training, combined with chronic CAP supplementation in healthy untrained men. We hypothesized that CAP could induce higher benefits when combined with resistance training after 10 weeks of intervention compared to resistance training alone. Twenty-four young men (age, 22.0 ± 2.9) were randomized to either capsiate supplementation (CAP = 12 mg/day) or placebo (PL), and both groups were assigned to resistance training. Body composition, leptin and adiponectin concentrations, subjective ratings of appetite, energy intake, and exercise performance were assessed at before and after 10 weeks of progressive resistance training. There was a significant increase in body mass (P < .001), fat-free mass (CAP: 58.0 ± 7.1 vs. post, 59.7 ± 7.1 kg; PL: pre, 58.4 ± 7.3 vs. post, 59.8 ± 7.1 kg; P < .001), resting metabolic rate (CAP: pre, 1782.9 ± 160.6 vs. post, 1796.3 ± 162.0 kcal; PL: pre, 1733.0 ± 148.9 vs. post, 1750.5 ± 149.8 kcal; P < .001), maximal strength at 45 leg press (P < .001) and bench press (P < .001) in both groups, but no significant (P > .05) supplementation by training period interaction nor fat mass was observed. For subjective ratings of appetite, energy intake, leptin, and adiponectin, no significant effect of supplementation by training period interaction was observed (P > .05). In conclusion, 10 weeks of resistance training increased total body weight, muscle mass, and maximum strength in healthy untrained men; however, CAP supplementation (12 mg, 7 days per week) failed to change adipose tissue-derived hormones, appetite, body composition and muscle strength in this population. Registered under Brazilian Registry of Clinical Trials (RBR-8cz9kfq).

Spontaneous Coronary Artery Dissection in a 19-Year-Old Male Athlete.

We present a 19-year-old male athlete, without cardiovascular risk factors, with anterior ST-segment elevation myocardial infarction caused by left anterior descending artery spontaneous coronary artery dissection. Symptoms began during a swim practice, and patient endorsed using C4 Ripped (Cellucor), a preworkout supplement to enhance athletic performance. We hypothesize that this was the major contributor to presentation. The patient showed improvement after 4 days.

The Effects of Two Servings of a Thermogenic Supplement on Metabolism, Hemodynamic Variables, and Mood State Outcomes in Young Overweight Adults.

Introduction We examined if acute ingestion of a novel thermogenic supplement influences resting energy expenditure (REE), mood, and hemodynamic function. Methods Forty-six adults completed this randomized, placebo-controlled, double-blind, crossover study. Participants underwent two conditions: placebo (PL) and treatment (TX) containing 300 mg of caffeine and 3 g of acetyl-L-carnitine. REE, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and mood states were assessed at baseline and 30, 60, and 120 minutes post-ingestion. Data were analyzed using repeated measures analysis of variance. Results A significant condition-by-time interaction was observed for REE. At the 30-, 60-, and 120-minute post-ingestion timepoints, REE was 202 ± 26, 238 ± 40, and 209 ± 29 kcal/d greater in the TX condition compared to PL. No significant differences were observed for SBP and HR but a significant interaction indicated that DBP was elevated at 30 minutes in the TX vs. PL, though values remained within normal ranges. Significant interactions were observed for perceived alertness, concentration, energy, and focus, with increases in TX. Conclusion These data provide evidence that acute consumption of the thermogenic dietary supplement OxyShred (EHPlabs, Salt Lake City, Utah, USA) stimulates increases in REE that are sustained for ≥ two hours, along with increasing perceived alertness, concentration, energy, and focus. Changes in hemodynamic function are minimal and within normal ranges.

Crushing Muscles: A Case Study on Rhabdomyolysis, Renal Failure, and Compartment Syndrome Triggered by Pre-Workout Supplement Abuse.

The use of steroids and protein-based dietary supplements for muscle enhancement is prevalent in contemporary society. While these products promise increased muscle mass and strength, they carry significant risks, including severe medical complications. The consumption of these supplements has been linked to adverse symptoms, including dehydration, gastrointestinal distress, dizziness, and alterations in heart rate and blood pressure, primarily due to ingredients like creatine, arginine, and caffeine. Following the proper dosage, ensuring adequate hydration, and consulting a healthcare provider to verify if the supplement's components could affect any pre-existing conditions is recommended. Indiscriminate use of these products, including taurine, can lead to serious side effects. We present a 36-year-old patient with severe rhabdomyolysis, life-threatening acid-base imbalance, renal and liver injury, and peripheral neuropathy associated with the use of performance-enhanced unregulated supplements and exercise. This case highlights the importance of recognizing and managing complications related to exercise-aid supplements, emphasizing early identification and management. Increasing social awareness and research on those products is highly needed to avoid supplement-associated complications and potential long-term disabilities.

Acute myocardial infarction following "dry scooping" of a pre-workout supplement in a healthy young man of African origin: A case report.

Dry scooping, a rather risky act of consuming undiluted pre-workout protein powder hoping for a more pronounced energy surge, is increasingly becoming a fitness trend worldwide. A previously healthy 25-year-old man of African origin presented with acute onset of crushing mid-sternal chest pain for 4 h. His symptoms began about an hour following completion of his 2-h exercise regimen at the gym. He had an unremarkable past medical history except for an 8-month consumption of a pre-workout supplement as part of his gym routine. He claimed to have adhered to the manufacturer's recommended method of using the supplement, except for 3 days prior to presentation when he started "dry scooping" following the viewing of a video advocating such practice from his fitness WhatsApp group. Cardiac evaluation revealed features in keeping with diagnosis of anterolateral ST-elevation myocardial infarction. Emergency coronary angiography revealed a thrombotic lesion completely occluding the proximal left anterior descending coronary artery with TIMI 0 flow distally. After successful balloon angioplasty, a drug-eluting stent was implanted successfully, restoring TIMI 3 flow to the proximal left anterior descending coronary artery. This case report aims to raise awareness among both clinicians and the general public regarding the pervasiveness of pre-workout supplements, improper methods of consumption, and the potential life-threatening repercussions of misuse.

Effects of Four Weeks of In-Season Pre-Workout Supplementation on Performance, Body Composition, Muscle Damage, and Health-Related Markers in Basketball Players: A Randomized Controlled Study.

This randomized, double-blinded, experimental study investigated the effects of a four-week daily pre-workout supplementation (200 mg caffeine, 3.3 g creatine monohydrate, 3.2 g ß-alanine, 6 g citrulline malate, and 5 g BCAA) vs. placebo (isocaloric maltodextrin) on anaerobic (jumping, sprinting, agility, and the running-based anaerobic sprint test: RAST) and aerobic (Yo-Yo intermittent recovery test level 1) performance, as well as on body composition and selective muscle damage/health-related blood markers in well-trained basketball players during the in-season period. Eighteen basketball players (age: 24.4 ± 6.3 years, height: 185.7 ± 8.0 cm, weight: 85.7 ± 12.8 kg, body fat: 16.5 ± 4.2%) were randomly assigned into two groups: pre-workout supplement (PWS, n = 10) or placebo (PL, n = 8). PWS consumption increased aerobic performance (PWS: 8 ± 6%; PL: -2 ± 6%; p = 0.004) compared to PL. A significant decrease was observed in peak (F = 7.0; p = 0.017), average (F = 10.7; p = 0.005), and minimum power (F = 5.1; p = 0.039) following 4 weeks of supplementation in both groups. No other significant changes were observed between groups (p > 0.05). In conclusion, the consumption of the current PWS over a four-week period appears to positively influence the aerobic performance of well-trained basketball players during the in-season period. However, it does not appear to mitigate the observed decline in anaerobic power, nor does it affect performance in jumping, sprinting, and agility, or alter body composition or selective muscle damage/health-related blood markers.

Does Beta-Alanine Supplementation Potentiate Muscle Performance Following 6 Weeks of Blood Flow Restriction or Traditional Resistance Training?

We aimed to compare the effects of beta-alanine on Traditional Resistance Training (TRAD) or Blood Flow Restriction Training (BFR). METHODS: 19 subjects were randomly allocated to a Placebo (n = 10) or beta-alanine (n = 9) group. Subjects from both groups were trained unilaterally (unilateral arm curl) for six weeks, and each arm was trained using a different paradigm (BFR or TRAD). One repetition maximum (1RM) test measurements were performed before and after the strength training program. Work output was accessed as the total weight lifted (repetitions × weight lifted × sets) for the entire strength training program. RESULTS: 1RM or total weight lifted was not increased by beta-alanine supplementation. However, the TRAD-trained arm showed a significantly increased 1RM and total weight lifted compared to the BFR arm (p < 0.05). CONCLUSION: We conclude that in the short-term (6 weeks) and following the current experimental conditions, beta-alanine does not benefit BFR or TRAD in terms of total weight lifted (volume of training) or maximal strength (1RM).

A single dose of dihydrocapsiate does not improve neuromuscular performance in resistance-trained young adults: A randomised, triple-blinded, placebo-controlled, crossover trial.

Capsinoids may exert ergogenic effects on resistance exercises. However, the acute effects of capsinoids on neuromuscular performance in humans are unknown. Here, we aimed to investigate the acute effects of dihydrocapsiate on lower- and upper-body neuromuscular performance parameters in resistance-trained individuals. 25 young adults (n = 6 women; age = 26 ± 3 years; body mass index = 24.3 ± 2.8 kg/m2) with ≥ 1-year resistance training experience were included in this triple-blind (participants, intervention researchers, and data analysts were blinded), placebo-controlled, crossover study. Lower- and upper-body ballistic strength (countermovement jump [CMJ] height and bench press throw [BPT] peak velocity), maximum dynamic strength (estimated 1 repetition maximum in squat and bench press [BP]), and strength-endurance (mean set velocity [squat] and number of repetitions to failure [bench press]) were assessed in 2 independent sessions (≥7 days separation). Participants ingested 12 mg of dihydrocapsiate or placebo 30 min before each trial. We found no significant differences between dihydrocapsiate and placebo conditions in ballistic strength, (CMJ height 33.20 ± 8.07 vs 33.32 ± 7.85 cm; BPT peak velocity 2.82 ± 0.77 vs 2.82 ± 0.74 m/s) maximal dynamic strength (estimated squat 1RM: 123.76 ± 40.63 vs 122.66 ± 40.97 kg; estimated BP 1RM: 99.47 ± 43.09 vs 99.60 ± 43.34 kg), and strength-endurance (squat mean set velocity 0.66 ± 0.07 vs 0.66 ± 0.05 m/s; number BP repetitions to failure 13.00 ± 3.56 vs 13.00 ± 4.78) (all P ≥ 0.703). We conclude that dihydrocapsiate does not acutely improve neuromuscular performance in trained young adults.

Capsinoids ­ non-pungent analogs of capsaicin ­ have been recently proposed as potential ergogenic compounds in humans.However, the effects of a single dose of capsinoids on neuromuscular performance parameters in humans remains unknown.12 mg of dihydrocapsiate does not improve neuromuscular performance in resistance-trained young adults.Dihydrocapsiate should not be recommended as an ergogenic aid to acutely increase neuromuscular performance.

Prevalence and correlates of dry scooping: Results from the Canadian Study of Adolescent Health Behaviors.

Dry scooping is a novel dietary practice characterized by consuming pre-workout powders without mixing with a liquid as directed. Despite purported benefits of this practice, such as increased energy due to the high concentration of caffeine, there are potential harms of engagement. To date, no known empirical research has investigated dry scooping in epidemiological research. Therefore, the aim of this study was to characterize the prevalence and correlates of dry scooping among a sample of Canadian adolescents and young adults. Data from the Canadian Study of Adolescent Health Behaviors (N = 2731) were analyzed. Prevalence of any dry scooping in the past 12 months among the overall sample, and by gender, was estimated. Modified Poisson regression analysis was used to determine the adjusted associations between sociodemographic and descriptive characteristics and dry scooping. Overall, 16.9 % of the sample reported dry scooping in the past 12 months, which was significantly more common among men (21.8 %) compared to women (14.2 %) and transgender/gender non-confirming participants (8.0 %). Participants who reported weight training, greater time spent on social media, and clinically significant symptoms of muscle dysmorphia were more likely to report dry scooping, while sexual minorities, relative to heterosexual participants, and those with higher education were less likely to report dry scooping. This study is the first known epidemiological study of dry scooping, underscoring the common nature of this contemporary dietary behavior. Findings emphasize the need for future research and prevention and intervention efforts to protect the health and well-being of young people.

Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine.

The use of pre-workout supplements has become increasingly popular, including the use of supplements containing synephrine. Synephrine might stimulate weight loss and improve sports performance by its proposed adrenergic properties. However, with its increasing popularity, numerous cases of adverse events related to synephrine use have been reported. This study provides a comprehensive overview and analysis of current case reports related to the supplemental use of synephrine. The scientific literature on cases of adverse events related to synephrine intake was collected through August 2021 using Pubmed and Google Scholar and subsequently reviewed and analysed. We obtained 30 case reports describing a total of 35 patients who suffered from medical complaints following use of synephrine-containing supplements. The patients most often presented with chest pain, palpitations, syncope and dizziness. Commonly raised diagnoses were ischaemic heart disease, cardiac arrhythmias and cerebrovascular disease. Five patients were left disabled or remained on medication at last follow-up. We here show an association between the use of pre-workout supplements containing synephrine and adverse events, mainly related to the cardiovascular system. However, we cannot exclude a role of possible confounding factors such as caffeine. Thus, the use of pre-workout supplements containing synephrine may lead to serious adverse health events, and therefore, caution is needed.

Pre-workout Induced Demand Ischemia.

Pre-workout supplement use has increased in recent years. Multiple side effects and off-labeled substances have been reported. We report a case of a 35-year-old patient who recently started a pre-workout and was found to have sinus tachycardia, elevated troponin, and subclinical hyperthyroidism. The echocardiogram showed normal ejection fraction and no wall motion abnormality. Beta-blockade therapy with propranolol was offered, but she refused, and her symptoms and troponin levels improved after proper hydration within 36 hours. A cautious and accurate assessment of young, fitness-enthusiastic patients experiencing unusual chest pain is essential to identify a reversible cardiac injury and possible off-label substances in over-the-counter supplements.

Pre-Workout-Induced Pancreatitis.

The use of dietary supplements, including pre-workout formulations, has gained widespread popularity among individuals engaged in sports and fitness. This case report presents a unique instance of pre-workout-induced pancreatitis in a previously healthy young adult. The patient, a 35-year-old male, presented to the emergency department with abdominal pain, elevated pancreatic enzymes, and characteristic radiological findings indicative of acute pancreatitis. The patient's history revealed no prior predisposing factors for pancreatitis such as alcohol consumption or gallstone disease. Extensive diagnostic evaluation excluded other potential causes leading to the suspicion of his pre-workout supplement as the source. Pre-workout supplements contain a blend of stimulants, amino acids, and other metabolic ingredients designed to enhance exercise and muscle performance. Research shows that some of these ingredients, such as amino acids, induce metabolic chain reactions which may damage pancreatic cells. However, there is extremely limited literature regarding these amino acids in combination such as in workout supplements. This case prompts an examination of the potential adverse effects of pre-workout supplements, highlighting the need for increased vigilance among healthcare providers and consumers alike. As the use of these products grows, further research is warranted to allow for safe commercial distribution and to protect consumers from serious harm.

Acute Low-Dose Capsiate Supplementation Improves Upper Body Resistance Exercise Performance in Trained Men: A Randomized, Crossover and Double-Blind Study.

Objectives: The purpose of this study was to compare the effects of two acute doses of Capsiate (CAP; 6 vs. 12 mg) on upper body resistance exercise performance in trained men. Methods: Using a randomized, crossover and double-blind design, 20 resistance-trained males were supplemented with low-dose CAP (6 mg), high-dose CAP (12 mg) or placebo 45 minutes before exercise. Subjects performed 4 sets of bench press with repetitions to failure at 70% 1 repetition maximum (1RM) and 2 minutes of rest between each set. The ratings of perceived exertion (RPE) and blood lactate were analyzed at baseline and after exercise. Results: Total weight lifted was greater in the low CAP (2,454.6 ± 448.6 kg) compared to placebo (2,354.7 ± 458.6 kg, p = 0.039) and high CAP (2,309.3 ± 428.1 kg, p = 0.001). There was no significant difference between conditions for RPE (p = 0.155) and blood lactate (p = 0.434). Conclusion: In summary, 6 mg CAP increased total weight lifted and repetitions to failure on bench press exercise in trained men, while 12 mg did not present any effect.

Nutritional interventions for improving the endurance performance in athletes.

Endurance refers to the ability of skeletal muscles to perform continuously withstanding the hardships of exercise. Endurance exercises have three phases: pre-, during-, and post-workout phase. The nutritional requirements that drive these phases vary on intensity, type of workout, individual's body composition, training, weather conditions, etc. Generally, the pre-workout phase requires glycogen synthesis and spare glycogen breakdown. While workout phase, requires rapid absorption of exogenous glucose, insulin release to transport glucose into muscle cells, replenish the loss of electrolytes, promote fluid retention, etc. However, post-workout phase requires quick amino acid absorption, muscle protein synthesis, repair of damaged muscle fibres and tendon, ameliorate inflammation, oxidative stress, etc. Therefore, nutritional sources that can help these metabolic requirements is recommended. In this review, various dietary interventions including timing and amount of nutrient consumption that can promote the above metabolic requirements that in turn support in improving the endurance potential in athletes are discussed.HIGHLIGHTSReview article describes nutritional requirements of endurance exercises.It also describes nutritional interventions to enhance the endurance potential in athletes.