Journal of the International Society of Sports Nutrition最新文献

{"title":"Sex-specific impacts of caffeine on body composition: commentary on a retrospective cohort study.","authors":"Anna Vittoria Mattioli","doi":"10.1080/15502783.2025.2454633","DOIUrl":"10.1080/15502783.2025.2454633","url":null,"abstract":"<p><strong>Background: </strong>Understanding the impact of caffeine intake on body composition is a topic of growing research interest. The article \"Association Between Caffeine Intake and Fat-Free Mass Index: A Retrospective Cohort Study\" by Tian et al. explored this relationship, highlighting a positive correlation between caffeine consumption and fat-free mass index (FFMI). In this letter to the editor, we discuss the broader implications of these findings, emphasizing the need for further exploration of the underlying biological and lifestyle factors influencing caffeine's effects.</p><p><strong>Objective: </strong>To provide critical insights into the mechanisms and contextual factors that may explain the observed association between caffeine intake and FFMI, with particular focus on sex-specific differences, hormonal influences, and lifestyle interactions.</p><p><strong>Methods: </strong>This letter to editor builds on the findings of Tian et al., drawing from related literature and prior research to contextualize the potential mechanisms and broader implications of caffeine's impact on body composition. The discussion highlights key areas requiring further investigation, including the role of hormonal modulation, genetic variability, and long-term effects on muscle health.</p><p><strong>Discussion: </strong>The positive association between caffeine intake and FFMI, particularly among women and younger populations, underscores the ergogenic potential of caffeine in enhancing muscle performance and metabolic efficiency. This letter expands on the study by emphasizing the role of hormonal factors, such as estrogen's modulation of CYP1A2, the liver enzyme critical for caffeine metabolism. The discussion also highlights the complex interplay between caffeine and other lifestyle factors. Finally, this commentary calls attention to the need for more research into the differential effects of caffeine sources, such as energy drinks and supplements, which often include additional ingredients with distinct metabolic and cardiovascular effects. These alternative sources may influence body composition differently than traditional coffee-based caffeine intake, an area that remains underexplored.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2454633"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11749007/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143007585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The dose-response effects of flurbiprofen, indomethacin, ibuprofen, and naproxen on primary skeletal muscle cells.","authors":"Brandon M Roberts, Alyssa V Geddis, Ronald W Matheny","doi":"10.1080/15502783.2024.2302046","DOIUrl":"10.1080/15502783.2024.2302046","url":null,"abstract":"<p><strong>Background: </strong>Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, flurbiprofen, naproxen sodium, and indomethacin are commonly employed for their pain-relieving and inflammation-reducing qualities. NSAIDs work by blocking COX-1 and/or COX-2, enzymes which play roles in inflammation, fever, and pain. The main difference among NSAIDs lies in their affinity to these enzymes, which in turn, influences prostaglandin secretion, and skeletal muscle growth and regeneration. The current study investigated the effects of NSAIDs on human skeletal muscle cells, focusing on myoblast proliferation, differentiation, and muscle protein synthesis signaling.</p><p><strong>Methods: </strong>Using human primary muscle cells, we examined the dose-response impact of flurbiprofen (25-200 µM), indomethacin (25-200 µM), ibuprofen (25-200 µM), and naproxen sodium (25-200 µM), on myoblast viability, myotube area, fusion, and prostaglandin production.</p><p><strong>Results: </strong>We found that supraphysiological concentrations of indomethacin inhibited myoblast proliferation (-74 ± 2% with 200 µM; -53 ± 3% with 100 µM; both <i>p</i> < 0.05) compared to control cells and impaired protein synthesis signaling pathways in myotubes, but only attenuated myotube fusion at the highest concentrations (-18 ± 2% with 200 µM, <i>p</i> < 0.05) compared to control myotubes. On the other hand, ibuprofen had no such effects. Naproxen sodium only increased cell proliferation at low concentrations (+36 ± 2% with 25 µM, <i>p</i> < 0.05), and flurbiprofen exhibited divergent impacts depending on the concentration whereby low concentrations improved cell proliferation (+17 ± 1% with 25 µM, <i>p</i> < 0.05) but high concentrations inhibited cell proliferation (-32 ± 1% with 200 µM, <i>p</i> < 0.05).</p><p><strong>Conclusion: </strong>Our findings suggest that indomethacin, at high concentrations, may detrimentally affect myoblast proliferation and differentiation via an AKT-dependent mechanism, and thus provide new understanding of NSAIDs' effects on skeletal muscle cell development.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2302046"},"PeriodicalIF":5.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10783825/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139417422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of spinach thylakoid extract-induced 12-week high-intensity functional training on specific adipokines in obese males.","authors":"Ayoub Saeidi, Pezhman Motamedi, Maha Hoteit, Zahra Sadek, Wiam Ramadan, Marjan Mansouri Dara, Abdullah Almaqhawi, Shahnaz Shahrbanian, Hossein Abednatanzi, Kurt A Escobar, Zhaleh Pashaei, Maisa Hamed Al Kiyumi, Ismail Laher, Hassane Zouhal","doi":"10.1080/15502783.2024.2398467","DOIUrl":"10.1080/15502783.2024.2398467","url":null,"abstract":"<p><strong>Background: </strong>Obesity presents multifarious etiopathologies with its management being a global challenge. This article presents the first ever report on the impact of spinach thylakoid extract-induced high-intensity functional training (HIFT) on obesity management via regulating the levels of novel adipokine, C1q/TNF-related Protein-12 (CTRP-12), furin, and Krüppel-like factor 15 (KLF-15).</p><p><strong>Methods: </strong>Sixty-eight obese male subjects were randomly divided into four groups: control group (CG), supplement group (SG), training group (TG), and the combined training and supplement group (TSG). After initial assessments of all groups, the training group commenced a twelve-week HIFT using the CrossFit program (comprising of three training sessions per week, each lasting 30 min). Eligible candidates were randomly assigned to either receive thylakoid-rich spinach extract (5 g per day) or a matching placebo (5 g per day of corn starch, 30 min before lunch) for a total duration of 12 weeks. All required data and investigations were collected at 48 h pre- and post-training.</p><p><strong>Results: </strong>The results indicated a substantial correlation between exercise and the time of KLF-15, furin, and CTRP-12 demonstrating effect sizes of 0.3, 0.7, and 0.6, respectively. Additionally, the training and supplementation group (TSG) exhibited a substantial decrease in low-density lipoprotein (LDL), total cholesterol (TC), and triglyceride (TG) levels (<i>p</i> < 0.0001). Concurrently, there was a significant increase in high-density lipoprotein-cholesterol (HDL-C) levels (<i>p</i> = 0.0001). Furthermore, a notable difference between the groups emerged in HDL, LDL, TC, and TG levels, supported by effect sizes of 0.73, 0.86, 0.96, and 0.89, respectively (<i>p</i> < 0.05).</p><p><strong>Conclusion: </strong>The study offered novel insights into the management of obesity using supplements induced by spinach-derived thylakoid extract during a 12-week HIFT program. The proposed combination intervention may reverse obesity-induced insulin resistance and metabolic dysfunctions by positive regulation of CTRP-12/adipolin and KLF15 and simultaneous suppression of furin levels.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2398467"},"PeriodicalIF":4.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11421126/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does green tea catechin enhance weight-loss effect of exercise training in overweight and obese individuals? a systematic review and meta-analysis of randomized trials.","authors":"Farhad Gholami, Jose Antonio, Mohadeseh Iranpour, Jason Curtis, Flavia Pereira","doi":"10.1080/15502783.2024.2411029","DOIUrl":"10.1080/15502783.2024.2411029","url":null,"abstract":"<p><strong>Background: </strong>Green tea (GT) is a common component of supplements known as fat burners. It has gained popularity as an ergogenic aid for weight reduction to assist with obesity management. This systematic review and meta-analysis aim to explore the effect of green tea ingestion coupled with exercise training (EX) on body composition and lipid profile in overweight and obese individuals.</p><p><strong>Methods: </strong>Two independent researchers systematically searched the electronic databases of PubMed, Web of Science, and Scopus. Studies with a randomized-controlled design to compare the effect of green tea in conjunction with exercise training (EX+GT) versus exercise training alone (EX+P) in overweight or obese participants were included.</p><p><strong>Results: </strong>Of the 1,015 retrieved studies, 24 were identified to undergo full-text review, out of which 10 randomized trials met the inclusion criteria. EX+GT versus EX+P had a small and consistent effect on weight [Standardized mean difference (SMD) = -0.30, CI: -0.53 to -0.07], BMI [SMD = -0.33 CI: -0.64 to -0.02] and fat reduction [SMD = -0.29, CI: -0.57 to -0.01] and there was no evidence of heterogeneity across the trials. When compared to EX+P, EX+GT had no greater effect on lipid profile improvement [triglyceride: SMD = -0.92, CI: -1.30 to 0.49; LDL: SMD = -1.44, CI: -0.73 to 0.82; HDL: SMD = 0.56, CI -0.71 to 0.46; and total cholesterol SMD = -0.54, CI -0.85 to 0.13].</p><p><strong>Conclusions: </strong>Current evidence suggests that green tea could have quite minimal additive benefit over exercise-induced weight loss. However, incorporation of green tea into exercise training does not seem to exert additional benefits on lipid profile and it warrants further investigations in the future.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2411029"},"PeriodicalIF":4.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11445908/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antifatigue effect of okara protein hydrolysate supplementation during cycling exercise in men: a pre-post uncontrolled pilot study.","authors":"Yu-Jou Chien, Jung-Piao Tsao, Chun-Tse Tsai, I-Shiung Cheng, Chin-Lin Hsu","doi":"10.1080/15502783.2024.2416479","DOIUrl":"https://doi.org/10.1080/15502783.2024.2416479","url":null,"abstract":"<p><strong>Background: </strong>Prolonged exercise usually leads to exercise fatigue, which has a negative short-term impact on exercise performance and metabolic rate; thus, fatigue needs to be resolved. Okara is a protein-rich residue of soy processing. Enzyme hydrolysis is known to increase the content of branched-chain amino acids (BCAAs), which have been reported to confer benefits for exercise. The purpose of this study was to investigate the antifatigue effect of okara protein hydrolysate (OPH) on cycling exercise.</p><p><strong>Methods: </strong>A total of 16 male participants who habitually exercised (2 times or more per week and without participation in athletic contests) were instructed to receive 11.74 g of OPH once a day. They then completed two intense cycling exercise challenges before and after four weeks of supplementation. Exercise time and blood markers related to fatigue and energy metabolism were measured.</p><p><strong>Results: </strong>The results showed that the time to exhaustion significantly increased after the treatment. The levels of lactate during exercise and at the end of exercise were significantly lower after treatment than before. Additionally, postexercise insulin sensitivity was increased after treatment.</p><p><strong>Conclusions: </strong>This study showed that OPH supplementation can promote endurance in exercise by decreasing the accumulation of fatigue-related metabolites during exercise and can promote energy recovery by increasing insulin function. These findings suggest that OPH has an antifatigue property.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2416479"},"PeriodicalIF":4.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11488163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?","authors":"Jose Antonio, Daniel E Newmire, Jeffrey R Stout, Brandi Antonio, Maureen Gibbons, Lonnie M Lowery, Joseph Harper, Darryn Willoughby, Cassandra Evans, Dawn Anderson, Erica Goldstein, Jose Rojas, Matías Monsalves-Álvarez, Scott C Forbes, Jose Gomez Lopez, Tim Ziegenfuss, Blake D Moulding, Darren Candow, Michael Sagner, Shawn M Arent","doi":"10.1080/15502783.2024.2323919","DOIUrl":"10.1080/15502783.2024.2323919","url":null,"abstract":"<p><p>Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords \"caffeine\" and \"exercise\" yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine's effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon \"crash?\" To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2323919"},"PeriodicalIF":5.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10930107/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140094266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muscle contraction time after caffeine intake is faster after 30 minutes than after 60 minutes.","authors":"Paweł Pakosz, Mariusz Konieczny, Przemysław Domaszewski, Tomasz Dybek, Oscar García-García, Mariusz Gnoiński, Elżbieta Skorupska","doi":"10.1080/15502783.2024.2306295","DOIUrl":"10.1080/15502783.2024.2306295","url":null,"abstract":"<p><strong>Background: </strong>This study aimed to determine the optimal time point, either 30 or 60 minutes, at which muscle reactivity to caffeine administration is highest. Unlike previous studies that focused on the nervous system response, we employed tensiomyography (TMG) to directly assess the effects of caffeine on muscle fibers.</p><p><strong>Methods: </strong>TMG measurements were performed on the gastrocnemius medialis muscle of 42 male athletes who regularly consumed caffeine. Participants received a dose of 6 mg/kg body weight and TMG measurements were taken prior to caffeine intake, as well as 30 and 60 minutes afterward.</p><p><strong>Results: </strong>Analysis of TMG parameters including time to contraction (Tc), time delay (Td), and maximal displacement (Dm) revealed that muscles exhibited faster contractions and greater stiffness at the 30-minute mark compared to both pre-caffeine intake and the 60-minute time point. Time exerted a significant main effect on Tc (F(2, 246) = 12.09, <i>p</i> < .001, ή2p = 0.09), Td (F(2, 246) = 3.39, <i>p</i> = .035, ή2p = 0.03), and Dm (F(2, 246) = 6.83, <i>p</i> = .001, ή2p = 0.05), while no significant effect of body side was observed.</p><p><strong>Conclusions: </strong>The findings indicate that muscle contraction time (Tc) and delay time (Td) are influenced by the time elapsed since caffeine ingestion, with the fastest responses occurring after 30 minutes. Additionally, a systemic effect of caffeine was observed, as there were no discernible differences in measurements between the two sides of the body. TMG proves to be an effective noninvasive method for assessing muscle responses following caffeine administration.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2306295"},"PeriodicalIF":4.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10802797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139491349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of quercetin and citrulline on cycling time trial performance.","authors":"Jennifer A Kurtz, Jacob Grazer, Kathryn Wilson, Rafaela G Feresin, J Andrew Doyle, Ryan Middleton, Emma Devis, Trisha A VanDusseldorp, Kimberly Fasczewski, Jeff Otis","doi":"10.1080/15502783.2024.2416909","DOIUrl":"10.1080/15502783.2024.2416909","url":null,"abstract":"<p><strong>Background: </strong>There is growing interest in the use of nutrition and dietary supplements to optimize training and time-trial (TT) performance in cyclists. Separately, quercetin (QCT) and citrulline (CIT) have been used as ergogenic aids to improve oxygen (VO₂) kinetics, perceived effort, and cycling TT performance. However, whether the combination of QCT and CIT can provide additive benefits and further enhance cycling performance production is currently unknown.</p><p><strong>Methods: </strong>We examined 28-days of QCT + CIT supplementation on TT performance and several performance measures (i.e. mean power, VO₂, respiratory exchange ratio (RER), and rate of perceived exertion (RPE)). Forty-eight highly trained cyclists were assigned to one of four supplementation groups: (1) QCT + CIT (QCT: 500 mg, CIT: 3000 g), (2) QCT (500 mg), (3) CIT (3000 mg), or (4) placebo (3500 mg of a zero-calorie flavored crystal light package). Supplements were consumed two times per day for 28 consecutive days. Participants performed a 20-km cycling time-trial race, pre- and post-supplementation to determine the impact of the combined effects of QCT + CIT.</p><p><strong>Results: </strong>There were no potential benefits of QCT +CIT supplementation on TT performance and several performance measures. However, there was an improvement in VO₂ from pre-to-post-supplementation in QCT (<i>p</i>  = 0.05) and CIT (<i>p</i>  = 0.04) groups, but not in the QCT+CIT and PL groups.</p><p><strong>Conclusions: </strong>QCT + CIT does not seem beneficial for 20-km TT performance; further exploration with a focus on an increase in cycling duration or QCT+CIT combined with additional polyphenols may amplify any perceived bioactive or metabolic effects on cycling performance. The efficacy of QCT + CIT supplementation to improve cycling performance remains ambiguous.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2416909"},"PeriodicalIF":4.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11488173/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute effects of various doses of nitrate-rich beetroot juice on high-intensity interval exercise responses in women: a randomized, double-blinded, placebo-controlled, crossover trial.","authors":"Zhang Jiaqi, Dai Zihan, Stephen Heung-Sang Wong, Zheng Chen, Eric Tsz-Chun Poon","doi":"10.1080/15502783.2024.2334680","DOIUrl":"10.1080/15502783.2024.2334680","url":null,"abstract":"<p><strong>Background: </strong>This study investigated the acute effects of various doses of nitrate-rich beetroot juice on the responses to high-intensity interval exercise in women.</p><p><strong>Methods: </strong>A double-blinded, randomized, placebo-controlled, crossover trial was conducted with 13 recreationally active young women (age = 23 ± 2 years). All participants performed interval exercise (8 × 1-min bouts of cycling at 85% of peak power output [PPO] interspersed with 1-min active recovery at 20% of PPO) 2.5 h after consumption of the randomly assigned beetroot juice containing 0 mmol (placebo), 6.45 mmol (single-dose), or 12.9 mmol (double-dose) <math><msubsup><mrow><mrow><mi>N</mi><mi>O</mi></mrow></mrow><mn>3</mn><mo>-</mo></msubsup></math>. The heart rate (HR), blood pressure, blood lactate, blood glucose, oxygen saturation, rating of perceived exertion (RPE), and emotional arousal were assessed.</p><p><strong>Results: </strong>Nitrate supplementation significantly altered the HR and RPE responses across the three trials. The mean HR was lower in the single- and double-dose groups than in the placebo control group during both work intervals and recovery periods, as well as across the overall protocol (all <i>p</i> < .05). The mean RPE was lower in the single- and double-dose groups than in the control group during recovery periods and across the overall protocol (all <i>p</i> < .001). However, there was no significant difference in either HR or RPE between the single- and double-dose groups at any time point.</p><p><strong>Conclusions: </strong>Acute nitrate ingestion led to significant decreases in the mean HR and RPE during high-intensity interval exercise, but no additional benefit was observed with higher nitrate content. These findings may assist practitioners in implementing more effective nitrate supplementation strategies during high-intensity interval exercise.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2334680"},"PeriodicalIF":5.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10977014/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140293878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of a sugar-free amino acid-containing electrolyte beverage on 5-kilometer performance, blood electrolytes, and post-exercise cramping versus a conventional carbohydrate-electrolyte sports beverage and water.","authors":"Mason C McIntosh, Bradley A Ruple, Nicholas J Kontos, Madison L Mattingly, Christopher M Lockwood, Michael D Roberts","doi":"10.1080/15502783.2023.2296888","DOIUrl":"10.1080/15502783.2023.2296888","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;The purpose of this study was to examine the acute effects of a multi-ingredient, low calorie dietary supplement (MIDS, XTEND® Healthy Hydration) on 5-kilometer (5-km) time trial performance and blood electrolyte concentrations compared to a carbohydrate-electrolyte beverage (CE, GATORADE® Thirst Quencher) and distilled water (W).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;During visit 1 (V1), participants (10 men and 10 women, 20-35 years old, BMI ≤ 29 kg/m&lt;sup&gt;2&lt;/sup&gt;, recreationally active) reported to the laboratory whereby the following tests were performed: i) height and weight measurements, ii) body composition analysis, iii) treadmill testing to measure maximal aerobic capacity, and iv) 5-km time trial familiarization. The second visit (V2) was one week after V1 in the morning (0600 - 0900) and participants arrived 12-14 h fasted (no food or drink). The first battery of assessments (V2-T1) included nude body mass, urine specific gravity (USG), a profile of mood states (POMS) questionnaire, and the completion of a visual analogue scale (VAS) questionnaire to quantify cramping. Then heart rate (HR), blood pressure (BP), total body hydration (via bioelectrical impedance spectroscopy [BIS]) were examined. Finally, a measurement of blood markers via finger stick was performed. Participants consumed a randomized beverage (16 fl. oz. of MIDS, 16 fl. oz. of W, or 16 fl. oz. of CE) within 3 min followed by a 45-min rest. Following the rest period, a second battery (V2-T2) was performed whereby participants' USG was assessed and they completed the POMS and VAS questionnaires, and HR, BP, and blood markers were measured. The participants then performed a 5-km treadmill time trial. Immediately following the 5-km time trial, participants completed a third testing battery (V2-T3) that began with blood markers, HR and BP assessments, followed by nude body weight assessment, and the POMS and VAS questionnaires. After 60 min, a fourth battery (V2-T4) was performed that included HR, BP, and blood markers. After sitting quietly for another 60 min a fifth battery assessment was performed (V2-T5) that included participants' USG, POMS and VAS questionnaires, HR, BP, blood markers, and total body hydration. Visits 3 (V3) and 4 (V4) followed the same protocol except a different randomized drink (16 oz. of CE, MIDS, or W) was consumed; all of which were separated by approximately one week.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;No differences occurred between conditions for 5-km time trial completion, indirect calorimetry outcomes during 5-km time trials, USG, or nude mass measurements (&lt;i&gt;p&lt;/i&gt; &gt; 0.05 for all relevant statistical tests). However, blood potassium and the sodium/potassium ratio displayed significant interactions (&lt;i&gt;p&lt;/i&gt; &lt; 0.05), and post hoc testing indicated these values were better maintained in the MIDS versus other conditions. Post-exercise cramp prevalence was greater in the CE (&lt;i&gt;p&lt;/i&gt; &lt; 0.05) and trended higher with W (&lt;i&gt;p&lt;","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"21 1","pages":"2296888"},"PeriodicalIF":5.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10763896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138830206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}