{"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}
Kworweinski Lafontant, Alexa Rukstela, Ardis Hanson, Janet Chan, Yasamian Alsayed, Wayne A Ayers-Creech, Cassidy Bale, Yuto Ohigashi, John Solis, Gretchen Shelton, Indira Alur, Cassandra Resler, Andrew Heath, Savannah Ericksen, Scott C Forbes, Bill I Campbell
{"title":"Comparison of concurrent, resistance, or aerobic training on body fat loss: a systematic review and meta-analysis.","authors":"Kworweinski Lafontant, Alexa Rukstela, Ardis Hanson, Janet Chan, Yasamian Alsayed, Wayne A Ayers-Creech, Cassidy Bale, Yuto Ohigashi, John Solis, Gretchen Shelton, Indira Alur, Cassandra Resler, Andrew Heath, Savannah Ericksen, Scott C Forbes, Bill I Campbell","doi":"10.1080/15502783.2025.2507949","DOIUrl":"10.1080/15502783.2025.2507949","url":null,"abstract":"<p><strong>Background: </strong>This systematic review and meta-analysis compared the differential effects of resistance training (RT), aerobic training (AT), and concurrent training (CT) on body mass and body fat loss in metabolically healthy individuals.</p><p><strong>Methods: </strong>A systematic search of PubMed, SportDiscus, and Web of Science databases for randomized controlled trials published between January 1980 and January 2023, comparing RT, AT, and CT in healthy adults was conducted. Primary outcomes of interest included changes in fat mass and body fat percentage; secondary outcomes were body mass and fat-free mass (FFM). Sub-analyses on intervention duration (< or ≥ 10 weeks), CT timing (aerobic and resistance exercises done on the same day versus different days within a week), and workload matching (equating workloads between AT, RT, and CT), were conducted. Study protocols followed PRISMA 2020 guidelines and were pre-registered on PROSPERO (CRD42023396530).</p><p><strong>Results: </strong>In total, 36 studies with 1564 participants were included in the systematic review, with only 31 studies included in the meta-analysis due to missing data. For studies lasting at least 10 weeks, AT outperformed RT in reducing body mass (mean difference (MD) = -1.82 kg [95% CI = -2.72 to -0.93]; <i>p</i> < 0.001) and fat mass (MD = -1.06 kg [95% CI = -1.88 to -0.24]; <i>p</i> = 0.01) but led to less FFM retention (MD = - 0.88 kg [95% CI = -1.73 to -0.03], <i>p</i> = 0.04). CT reduced significantly more fat mass compared to RT (MD: -1.09 kg [95% CI = -0.27 to -1.91]; <i>p</i> = 0.009). No significant differences were found between CT, AT, and RT in altering body fat percentage (<i>p</i> > 0.05). For studies shorter than 10 weeks, no significant differences were noted across exercise modalities (<i>p</i> > 0.05). Under conditions where AT, RT, and CT workloads were matched, similar fat mass, body mass, body fat percentage, and FFM changes were observed between exercise modalities (<i>p</i> > 0.05). Similar body mass and body fat percentage loss was observed between same-day and different-day CT (<i>p</i> > 0.05); body fat mass loss only differed in a single study (<i>n</i> = 1) when comparing RT to different-day CT (aerobic and resistance exercises done on different days within a week).</p><p><strong>Conclusions: </strong>While there are no differences in percent body fat loss between exercise modes, AT and CT are more effective than RT alone in reducing absolute fat mass; however, RT neither improved nor impeded fat mass loss when incorporated into CT. Combining aerobic and resistance exercises on the same-day or different-day does not appear to influence the effectiveness of CT. When exercise interventions are short in duration (<10 weeks), there does not appear to be a difference in fat loss between exercise modalities. These results support the concurrent use of aerobic and resistance exercises for fat mass reduction, as well as an emphasis on ","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2507949"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107660/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144128005","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}
Reza Sadeghi, Mohammad Hemmatinafar, Fereshteh Eftekhari, Babak Imanian, Negar Koureshfard
{"title":"Pre-sleep casein ingestion with probiotic strains improves anaerobic power and lower-body-specific strength and power performance in soccer players.","authors":"Reza Sadeghi, Mohammad Hemmatinafar, Fereshteh Eftekhari, Babak Imanian, Negar Koureshfard","doi":"10.1080/15502783.2025.2505184","DOIUrl":"10.1080/15502783.2025.2505184","url":null,"abstract":"<p><strong>Background: </strong>Probiotics comprise various strains that offer numerous health benefits. Researchers have recently focused on the relationship between probiotic consumption and improved gut microbiota function, enhanced digestion, increased nutrient absorption, and enhanced sports performance. Therefore, the present study investigated the effects of pre-sleep casein intake, coupled with probiotic strains, on soccer players' anaerobic power, lower-body-specific strength, and power performance.</p><p><strong>Methods: </strong>A randomized, double-blinded, and placebo-controlled study was conducted with forty-four male soccer players (Age: 22.81 ± 2.76 years, Height: 177.90 ± 6.75 cm, Weight: 67.42 ± 8.44 kg). The participants underwent the isokinetic strength, Wall-squat, and running-based anaerobic sprint (RAST) tests initially; then, they were randomly divided into four groups: probiotics (PRO), casein (CAS), probiotics with casein (PRO+CAS), and placebo (PLA). The PRO groups were given one probiotic capsule (containing eight bacterial strains: <i>Lactiplantibacillus plantarum</i> BP06, <i>Lacticaseibacillus casei</i> BP07, <i>Lactobacillus acidophilus</i> BA05, <i>Lactobacillus bulgaricus</i> BD08, Bifidobacterium infantis BI04, <i>Bifidobacterium longum</i> BL03, <i>Bifidobacterium breve</i> BB02, and <i>Streptococcus thermophilus</i> BT01, with a total dose of 4.5 × 10<sup>11</sup> CFU) during dinner, while the CAS groups consumed 20 grams of casein powder 45 minutes before bed. The PRO+CAS group was given one probiotic capsule during dinner and 20 grams of casein powder 45 minutes before bed. The participants in the PLA group were given one red capsule (containing 5 grams of starch) during dinner. All participants were instructed to take the supplements only on training days, three times a week for four weeks. Additionally, isokinetic strength parameters, including absolute peak torque (APT) and average rate of force development (AvRFD), were measured for the knee extensors (ext) and flexors (flx) muscles (concentric phase at angular velocities of 60°/s and 180°/s, using the dominant leg). One-way analysis of covariance (ANCOVA) or Quade tests with a significance level of <i>p</i> < 0.05 was used to analyze the collected data.</p><p><strong>Result: </strong>The current study's findings indicated that APT-180°/s (ext) significantly increased in CAS (<i>p</i> = 0.008) and PRO+CAS (<i>p</i> = 0.003) compared to PLA. Additionally, the AvRFD-180°/s (ext) increased significantly in the PRO compared to the PLA (<i>p</i> = 0.007). Also, the AvRFD-60°/s (flx) increased significantly in the PRO+CAS group compared to the PLA (<i>p</i> = 0.014), CAS (<i>p</i> = 0.001), and PRO (<i>p</i> = 0.007). Furthermore, the AvRFD-180°/s (flx) increased significantly in the PRO+CAS compared to the CAS (<i>p</i> = 0.010). Moreover, the RAST average power increased dramatically in PRO+CAS compared to PLA (<i>p</i> = 0.003) and CAS (<i>p</i> = 0.02). Ad","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2505184"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12077483/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144023064","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}
Christopher Chamberlin, Aldo Lena, Dimple Radia, Dale Rees, John Lodge, James Rutherford, Bruno Cesar da Silva Dos Santos, Bhaven Patel, Shawn McLaren
{"title":"Measuring bioelectric impedance outputs following coffee consumption in healthy adults using an 8-electrode segmental BIA device.","authors":"Christopher Chamberlin, Aldo Lena, Dimple Radia, Dale Rees, John Lodge, James Rutherford, Bruno Cesar da Silva Dos Santos, Bhaven Patel, Shawn McLaren","doi":"10.1080/15502783.2025.2528531","DOIUrl":"https://doi.org/10.1080/15502783.2025.2528531","url":null,"abstract":"<p><strong>Introduction: </strong>Bioelectric impedance analysis (BIA) is increasingly used to measure body composition in athletic, clinical and research settings. The reliability of BIA measurements relies on following procedures carefully. However, some practices for ensuring reliable measures may be unnecessarily restrictive. Previous research using BIA outputs as study outcome measures, has required participants to avoid coffee and caffeine-containing foods and beverages prior to measurements. The aim of this study was to determine whether BIA outputs are affected by coffee consumption at different caffeine concentrations.</p><p><strong>Methods: </strong>This study used a blinded, randomized, cross-over trial design. Participants (<i>n</i> = 13) received one of three treatments per visit: 200 mL hot water (80°C) mixed with 5 g instant coffee, 2.5 g instant coffee with 2.5 g decaffeinated coffee, or 5 g decaffeinated instant coffee. Body composition and fluid parameters were measured over 50 minutes using a Seca mBCA 515 device.</p><p><strong>Results: </strong>The treatment predictor (<i>p</i> > 0.05) and sex-time-treatment interaction for all outcomes was found to be non-significant (<i>p</i> > 0.05). The time predictor was statistically significant (<i>p</i> < 0.05) for impedance, resistance and reactance but not for phase angle ϕ50 (<i>p</i> = 0.731), ϕ5 (<i>p</i> = 0.059) or urine osmolality (<i>p</i> = 0.066). The sex predictor was statistically significant for Z<sub>50</sub> (<i>p</i> = 0.001), Z<sub>5</sub> (<i>p</i> = 0.002), R<sub>50</sub> (<i>p</i> = 0.001), R<sub>5</sub> (<i>p</i> = 0.002), ϕ<sub>50</sub> (<i>p</i> = 0.01), ϕ<sub>5</sub> (<i>p</i> = 0.049), fat mass (%) (<i>p</i> = 0.016) and fat free mass (%) (<i>p</i> = 0.016). The effect size for this predictor was η<sup>2</sup><sub>G</sub> < 0.336. A significant sex-time interaction was found for Z<sub>50</sub> (<i>p</i> = 0.025) with a small effect size (η<sup>2</sup><sub>G</sub> < 0.01). Effect sizes for the treatment predictor and time-treatment interaction were found to be small (η<sup>2</sup><sub>G</sub> < 0.01). Effect size for the time predictor was small (η<sup>2</sup><sub>G</sub> > 0.01).</p><p><strong>Conclusion: </strong>Changes in impedance, resistance and reactance were detected over the course of the experiment, and these changes were greater than could be explained by the technical error of measurement. However, the amount of caffeine in coffee did not affect BIA outputs. Effect sizes were small, suggesting little practical significance of drinking coffee before taking BIA measurements. Therefore, coaches, athletes, researchers and clinicians may be able to obtain reliable BIA measurements even when coffee has been consumed up to 50 minutes prior to measurements, however, fluid consumption and being adequately hydrated should still be considered.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2528531"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sex differences in energy intake, sweat rate, and electrolyte loss among world-class archers during competition.","authors":"Ozcan Esen, Stuart Goodall","doi":"10.1080/15502783.2025.2528532","DOIUrl":"https://doi.org/10.1080/15502783.2025.2528532","url":null,"abstract":"<p><strong>Background: </strong>Limited evidence reports energy and macronutrient intake during competitive archery and whether any sex differences exist. Understanding these factors will provide insights into physiological demands and could inform more effective strategies to optimize performance for all archers in this precision-demanding sport. This study aimed to evaluate sweat rate (SR), sweat electrolyte loss, and energy intake (EI) in world-class archers throughout competition.</p><p><strong>Method: </strong>Eight (4 females) elite-standard archers (age: 21 ± 2 and 19 ± 1 years; body mass: 65.1 ± 2.8 and 60.1 ± 4.1 kg; stature: 179.3 ± 5.1 and 162.3 ± 0.8 cm, for males and females, respectively) from the Turkish National Archery Team participated. Data were collected over four days; assessments of hydration, SR, sweat composition ([Na<sup>+</sup>] and [K<sup>+</sup>]), and nutritional intake were completed at the same time each day.</p><p><strong>Results: </strong>Male archers consumed more total energy (2,889 vs. 2,353 kcal, <i>p</i> = 0.007) and carbohydrates (5.3 vs. 3.9 g/kg, <i>p</i> = 0.046) compared to females, with intake fluctuating based on competition demands (i.e. match duration, and the total distance walked). SR and sweat [K<sup>+</sup>] loss, were greater in males compared to females (<i>p</i> ≤0.006). In contrast, no sex differences were observed in other hydration parameters (sweat [Na<sup>+</sup>] loss, urine-specific gravity). Moreover, all archers maintained adequate hydration status throughout the competition, with no differences in pre- and post-competition hydration levels (<i>p</i> > 0.05).</p><p><strong>Conclusion: </strong>This study expands on previous research by incorporating sex-specific analyses, demonstrating that while energy and carbohydrate intake varies between male and female archers, hydration-related variables remain consistent.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2528532"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammadyasin Lak, Scott C Forbes, Damoon Ashtary-Larky, Sahar Dadkhahfar, Reza Mahmoud Robati, Farshid Nezakati, Makan Khajevandi, Sara Naseri, Arvin Gerafiani, Neda Haghighat, Jose Antonio, Grant M Tinsley
{"title":"Does creatine cause hair loss? A 12-week randomized controlled trial.","authors":"Mohammadyasin Lak, Scott C Forbes, Damoon Ashtary-Larky, Sahar Dadkhahfar, Reza Mahmoud Robati, Farshid Nezakati, Makan Khajevandi, Sara Naseri, Arvin Gerafiani, Neda Haghighat, Jose Antonio, Grant M Tinsley","doi":"10.1080/15502783.2025.2495229","DOIUrl":"https://doi.org/10.1080/15502783.2025.2495229","url":null,"abstract":"<p><strong>Background: </strong>Creatine is a widely used ergogenic aid that enhances muscle strength and lean mass. However, concerns have been raised about the potential role in promoting hair loss by increasing dihydrotestosterone (DHT). Currently, there is no direct evidence examining the relationship between creatine supplementation and hair follicle health. Therefore, the purpose was to determine the effects of 12 weeks of creatine supplementation on androgen levels and hair follicle health in healthy young males.</p><p><strong>Methods: </strong>Forty-five resistance-trained males (ages 18-40 years) were recruited and randomly assigned to either a creatine monohydrate (5 g/day) or placebo (5 g maltodextrin/day) group. Participants maintained their habitual diets and training routines. Blood samples were collected at baseline and after 12 weeks to measure total testosterone, free testosterone, and DHT. Hair follicle health was assessed using the Trichogram test and the FotoFinder system (hair density, follicular unit count, and cumulative hair thickness). Statistical analyses were performed using repeated measures ANOVA, and potential outliers were examined through sensitivity analysis.</p><p><strong>Results: </strong>Thirty-eight participants completed the study, with no significant differences in baseline characteristics between groups. There were no group-by-time interactions observed for any hormones or hair-related outcomes (<i>p</i> > 0.05). While total testosterone increased (∆ = post value minus pre value: creatine = ∆124 ± 149 ng/dL; placebo = ∆216 ± 203 ng/dL) and free testosterone decreased (creatine = ∆-9.0 ± 8.7 pg/mL; placebo = ∆-9 ± 6.4 pg/mL) over time, these effects were independent of supplementation. There were no significant differences in DHT levels, DHT-to-testosterone ratio, or hair growth parameters between the creatine and placebo groups.</p><p><strong>Conclusion: </strong>This study was the first to directly assess hair follicle health following creatine supplementation, providing strong evidence against the claim that creatine contributes to hair loss.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 sup1","pages":"2495229"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12020143/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144013380","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}
Jeffrey R Stout, Richard B Kreider, Darren G Candow, Scott C Forbes, Eric S Rawson, Brandi Antonio, Jose Antonio
{"title":"The birth of modern sports nutrition: tracing the path from muscle biopsies to creatine supplementation-A narrative review.","authors":"Jeffrey R Stout, Richard B Kreider, Darren G Candow, Scott C Forbes, Eric S Rawson, Brandi Antonio, Jose Antonio","doi":"10.1080/15502783.2025.2463373","DOIUrl":"10.1080/15502783.2025.2463373","url":null,"abstract":"<p><strong>Background: </strong>Modern sports nutrition has evolved through discoveries in muscle metabolism and dietary supplementation. Advances in muscle biopsy techniques revealed how diet influences muscle energetics and exercise performance. The establishment of the Metabolic Research Laboratory provided a platform for further investigation, leading to the identification of creatine monohydrate (CrM) as an effective ergogenic aid. This review outlines the historical development of sports nutrition research from the 1960s to the early 1990s, highlighting key breakthroughs in muscle glycogen metabolism, dietary interventions, and creatine supplementation.</p><p><strong>Methods: </strong>We conducted a narrative review that combined personal accounts with seminal research studies. This approach allowed us to examine the contributions of Drs. Jonas Bergström and Eric Hultman-founders of the Metabolic Research Laboratory-as well as the early work of their postdoctoral colleague, Dr. Roger Harris.</p><p><strong>Results: </strong>Muscle biopsy techniques enabled direct analysis of muscle metabolism, leading to insights into glycogen depletion and recovery. The Metabolic Research Laboratory advanced our understanding of muscle energetics and informed dietary strategies for enhancing performance. In 1992, the rediscovery of CrM supplementation demonstrated its capacity to increase intramuscular creatine levels, significantly improving exercise performance and recovery. These breakthroughs reshaped sports nutrition and expanded its relevance to clinical and aging populations.</p><p><strong>Conclusion: </strong>The progression from early muscle metabolism research to the validation of CrM supplementation underscores how foundational laboratory discoveries have shaped modern sports nutrition. The work of the Metabolic Research Laboratory and its key investigators continues to inform applications in both performance enhancement and clinical health.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 sup1","pages":"2463373"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11837910/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441370","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}
Sergej M Ostojic, Daren G Candow, Mark A Tarnopolsky
{"title":"Creatine and post-viral fatigue syndrome: an update.","authors":"Sergej M Ostojic, Daren G Candow, Mark A Tarnopolsky","doi":"10.1080/15502783.2025.2517278","DOIUrl":"10.1080/15502783.2025.2517278","url":null,"abstract":"<p><p>Post-viral fatigue syndrome, classified as a neurological condition by the WHO (ICD-11 code: 8E49), manifests as persistent fatigue, cognitive difficulties, and post-exertional malaise following viral infections. It shares commonalities with chronic fatigue syndrome and myalgic encephalomyelitis but is distinct due to its association with preceding viral events. Emerging research identifies bioenergetic disruptions, particularly mitochondrial dysfunction and impaired creatine metabolism, as key contributors. Recent studies suggest creatine supplementation may alleviate symptoms and improve energy metabolism. This narrative review summarizes recent advancements in utilizing creatine as a diagnostic and therapeutic target for post-viral fatigue syndrome and explores future directions for its application in managing this perplexing condition.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 sup1","pages":"2517278"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12147496/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144248499","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}
Richard B Kreider, Drew E Gonzalez, Kelly Hines, Adriana Gil, Diego A Bonilla
{"title":"Safety of creatine supplementation: analysis of the prevalence of reported side effects in clinical trials and adverse event reports.","authors":"Richard B Kreider, Drew E Gonzalez, Kelly Hines, Adriana Gil, Diego A Bonilla","doi":"10.1080/15502783.2025.2488937","DOIUrl":"10.1080/15502783.2025.2488937","url":null,"abstract":"<p><strong>Background: </strong>Individual studies have indicated that creatine supplementation is generally well tolerated and not associated with clinically significant side effects. Nevertheless, anecdotal reports about side effects persist primarily from popular and social media and on the Internet.</p><p><strong>Methods: </strong>This study evaluated side effects reported from 685 human clinical trials on creatine supplementation, worldwide adverse event report (AER) databases, and performed a social media sentiment analysis. The presence of side effects (No, Yes) in studies was evaluated using chi-squared analysis. The frequency of side effects among study participants was evaluated using a multivariate analysis of variance.</p><p><strong>Results: </strong>A total of 13,452 participants in 652 studies ingested placebos (PLA), while 12,839 participants in 685 studies consumed creatine (Cr). Nearly all studies (95%) provided CrM at an average dose of 0.166 [0.159, 0.173] g/kg/d (about 12.5 g/d) for 64.7 [52.0, 77.3] days in studies lasting up to 14 yrs. Side effects were reported in 13.2% of studies in the PLA groups and 13.7% of studies in the Cr-supplemented groups, with no significant differences observed between the groups (<i>p</i> = 0.776). There was a slightly higher percentage of studies reporting gastrointestinal (GI) issues (PLA 4.3%, Cr 4.9%, <i>p</i> < 0.001) and muscle cramping/pain (PLA 0.9%, Cr 2.9%, <i>p</i> = 0.008) with Cr supplementation, but not when the total number of participants in these studies was evaluated (muscle cramping/pain: PLA 0.07%, Cr 0.52%, <i>p</i> = 0.085; GI issues: PLA 4.05%, Cr 5.51%, <i>p</i> = 0.820). Additionally, there was no significant multivariate difference among the 49 side effects evaluated (<i>p</i> = 0.340), no significant difference in the total frequency of side effects reported among participants (PLA 4.21%, Cr 4.60%, <i>p</i> = 0.828), and no significant differences in any of the other side effect evaluated that included markers of renal function and health. The percentage prevalence of side effects was small, with differences between groups generally within ± 0.5%. Analysis of 28.4 million AERs revealed that the mention of Cr was rare (0.00072%), 46.3% of CAERS had no Cr in the products listed, and 63% of AERs with Cr in the product involved the use of other types of Cr or ingestion with other supplements or drugs. The overall sentiment analysis was neutral about perceptions of Cr, although those with strong perceptions about Cr were slightly more negative.</p><p><strong>Conclusion: </strong>Results demonstrate that Cr supplementation does not increase the prevalence or frequency of side effects when compared to participants ingesting PLA. Therefore, claims that Cr supplementation increases the risk of side effects are unfounded.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 sup1","pages":"2488937"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11983583/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803710","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}
Brandon M Roberts, Alyssa V Geddis, Ronald W Matheny
{"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}