Journal of the International Society of Sports Nutrition最新文献

{"title":"Dosing strategies for β-alanine supplementation in strength and power performance: a systematic review.","authors":"Si-Wei Ong, Wei-Ling Chen, Kuei-Yu Chien, Chih-Wen Hsu","doi":"10.1080/15502783.2025.2566368","DOIUrl":"10.1080/15502783.2025.2566368","url":null,"abstract":"<p><strong>Background: </strong>β-alanine is a well-established ergogenic aid that enhances muscle carnosine levels and buffering capacity during high-intensity efforts. However, its role in improving strength and power performance remains inconsistent across the literature. This systematic review investigates whether dosing strategy, rather than duration alone, is the critical determinant of efficacy in resistance-trained populations.</p><p><strong>Methods: </strong>A systematic search was conducted across PubMed, SPORTDiscus, Scopus, Web of Science, and Google Scholar up to 28 May 2025, following PRISMA guidelines. Studies were included based on the PICO framework, targeting trained individuals receiving β-alanine supplementation with defined dosing protocols and strength- or power-based outcomes. Methodological quality was assessed using the Joanna Briggs Institute tools.</p><p><strong>Results: </strong>Nine studies comprising 197 participants were reviewed. Daily β-alanine doses between 4 g and 6.4 g, especially when divided into multiple smaller servings such as 0.8 g taken several times a day, were more likely to enhance maximal strength and power-related outcomes. In contrast, studies that used high total doses but relied on sustained-release formats, single large servings, or training protocols with limited metabolic stress such as low volume or long rest intervals often failed to show improvements in performance. These findings suggest that cumulative dose and delivery method may play a more critical role than duration alone in promoting strength and power adaptations.</p><p><strong>Conclusion: </strong>To optimize strength and power outcomes, β-alanine supplementation should emphasize fragmented dosing protocols of 4-6.4 g/day sustained over 5-8 weeks, particularly when implemented during training phases characterized by high metabolic stress - such as repeated submaximal efforts, short rest intervals, or high-volume hypertrophy sessions that elevate intramuscular acidity. These findings offer refined guidelines for coaches, athletes, and sport nutrition practitioners, and highlight the need for more individualized and mechanistically informed supplementation strategies.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2566368"},"PeriodicalIF":3.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12466178/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137653","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":"Part II. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?","authors":"Jose Antonio, Ann F Brown, Darren G Candow, Philip D Chilibeck, Stacey J Ellery, Scott C Forbes, Bruno Gualano, Andrew R Jagim, Chad Kerksick, Richard B Kreider, Sergej M Ostojic, Eric S Rawson, Michael D Roberts, Hamilton Roschel, Abbie E Smith-Ryan, Jeffrey R Stout, Mark A Tarnopolsky, Trisha A VanDusseldorp, Darryn S Willoughby, Tim N Ziegenfuss","doi":"10.1080/15502783.2024.2441760","DOIUrl":"10.1080/15502783.2024.2441760","url":null,"abstract":"<p><p>Creatine monohydrate supplementation (CrM) is a safe and effective intervention for improving certain aspects of sport, exercise performance, and health across the lifespan. Despite its evidence-based pedigree, several questions and misconceptions about CrM remain. To initially address some of these concerns, our group published a narrative review in 2021 discussing the scientific evidence as to whether CrM leads to water retention and fat accumulation, is a steroid, causes hair loss, dehydration or muscle cramping, adversely affects renal and liver function, and if CrM is safe and/or effective for children, adolescents, biological females, and older adults. As a follow-up, the purpose of this paper is to evaluate additional questions and misconceptions about CrM. These include but are not limited to: 1. Can CrM provide muscle benefits without exercise? 2. Does the timing of CrM really matter? 3. Does the addition of other compounds with CrM enhance its effectiveness? 4. Does CrM and caffeine oppose each other? 5. Does CrM increase the rates of muscle protein synthesis or breakdown? 6. Is CrM an anti-inflammatory intervention? 7. Can CrM increase recovery following injury, surgery, and/or immobilization? 8. Does CrM cause cancer? 9. Will CrM increase urine production? 10. Does CrM influence blood pressure? 11. Is CrM safe to consume during pregnancy? 12. Does CrM enhance performance in adolescents? 13. Does CrM adversely affect male fertility? 14. Does the brain require a higher dose of CrM than skeletal muscle? 15. Can CrM attenuate symptoms of sleep deprivation? 16. Will CrM reduce the severity of and/or improve recovery from traumatic brain injury? Similar to our 2021 paper, an international team of creatine research experts was formed to perform a narrative review of the literature regarding CrM to formulate evidence-based responses to the aforementioned misconceptions involving CrM.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2441760"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142885892","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":"Toward promoting performance nutrition behaviors among tactical athletes: a mixed methods study.","authors":"Bradley Baker, Julia Carins, Rosa Peterson, Regina Belski, Matthew B Cooke","doi":"10.1080/15502783.2025.2492186","DOIUrl":"https://doi.org/10.1080/15502783.2025.2492186","url":null,"abstract":"<p><strong>Background: </strong>Appropriate and adequate nutrition is essential for the health and performance of tactical athletes, including army recruits and trainees. However, previous research shows they commonly experience suboptimal intakes of energy and carbohydrate. To date, little research has been conducted to understand the causes of their poor dietary intakes. The objectives of this study were to (1) assess infantry trainees' dietary intakes and (2) explore their beliefs, barriers, and self-efficacy toward performance nutrition using the Health Belief Model (HBM).</p><p><strong>Methods: </strong>Participants undergoing their 17-week Australian Army Infantry Initial Employment Training (Infantry IET) were recruited. During weeks 1 and 17, self-reported dietary intakes were assessed, and four focus groups were conducted.</p><p><strong>Results: </strong>Mean daily energy, carbohydrate, and protein intakes were 7864 ± 1135 kJ, 1.8 ± 0.6 g/kg, and 1.5 ± 0.3 g/kg, respectively, in week 1, and 9084 ± 2535 kJ/day, 2.2 ± 1.1 g/kg and 1.5 ± 0.2 g/kg, respectively, in week 17. Three themes and seven subthemes were developed from the focus group data, falling under the following HBM domains: Cues to Action, Perceived Barriers, and Self-Efficacy.</p><p><strong>Conclusions: </strong>Infantry trainees' ability to eat well for their health and performance was hindered by their limited time during their intensive training schedule, their limited access to a sufficient variety of healthy foods, and their limited self-efficacy regarding performance nutrition. They require further performance nutrition knowledge, especially in regard to adopting practical fueling and refueling strategies surrounding physical training, as well as access to a greater quantity and variety of healthy foods outside of their main mealtimes.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2492186"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12051564/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020263","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":"Caregivers nutrition knowledge and perspectives on the enablers and barriers to nutrition provision for male academy football players.","authors":"Matthew Cole, Jennie L Carter, Frances Brooks, Charlie J Roberts","doi":"10.1080/15502783.2025.2495879","DOIUrl":"https://doi.org/10.1080/15502783.2025.2495879","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;The assessment of nutrition knowledge, alongside the enablers and barriers to optimal dietary intake, in youth football players has previously been documented. However, there is comparatively little research on either of these within parents or host families, which is of value to understand given the vital role that these stakeholders play as the primary food provider to young football players. Thus, the purpose of this study was to assess the nutrition knowledge of these caregivers and explore their perceptions of the barriers and enablers to nutrition provision for male academy football players.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A validated 35-item online questionnaire (A-NSKQ) was completed by 30 parents and 31 host family providers of youth academy football players from 16 different professional football clubs in England. The questionnaire consisted of 35 questions (total), 11 of which focussed on the assessment of general nutrition knowledge (GNK) and the remaining 24 assessed sports nutrition knowledge (SNK). Scores are presented as a percentage for total and each sub-section (GNK & SNK) and classified by the following rating: \"poor\" (0-49%); \"average\" (50-65%); \"good\" (66-75%); and \"excellent\" knowledge (76-100%). Differences in Total, GNK and SNK were compared between parents and host families using Independent-samples t-tests, with the alpha value set at &lt;i&gt;p&lt;/i&gt; &lt; 0.05 for all tests. A series of focus groups was also conducted with six parents and twelve host family representatives from four clubs to explore their perspectives of the enablers and barriers to providing nutrition support to youth football players. Thematic analysis was used to interpret the data.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Host family providers demonstrated significantly better total nutrition knowledge than Parents (49.95   ±   11.64% vs. &lt;i&gt;p&lt;/i&gt; = 42.67   ±   14.43%; &lt;i&gt;p&lt;/i&gt; = 0.035), although the knowledge of both groups is classed as \"poor.\" For the sub-sections of GNK & SNK, GNK was considered \"average\" and significantly better than SNK, which was classed as \"poor\" (GNK = 58.12   ±   16.87% vs. SNK = 40.98   ±   14.91%; &lt;i&gt;p&lt;/i&gt; &lt; 0.001). Host family providers reported significantly better SNK than parents (44.89   ±   13.21% vs. 36.94   ±   15.69%; &lt;i&gt;p&lt;/i&gt; = 0.037) whilst no significant differences were observed in GNK between groups (61.00   ±   15.07% vs. 55.15   ±   18.33%; &lt;i&gt;p&lt;/i&gt; = 0.180). Three key themes were generated relating to the caregivers' perceptions of the barriers and enablers to their food provision: 1) Club Support and Communication; 2) Time and Financial Resources; 3) Player-specific Characteristics.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;These findings suggest a clear need for football clubs to educate caregivers in the fundamental principles of healthy nutrition and football-specific nutrition requirements and encourage clubs to develop initiatives to better support caregivers in helping to young players to m","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2495879"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12016246/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144001342","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":"Caffeine's influence on vertical jump height: a real-life collegiate student-athlete approach.","authors":"Zacharias Papadakis, Vassilios Panoutsakopoulos, Antonella Schwarz, Jose Antonio","doi":"10.1080/15502783.2025.2501063","DOIUrl":"https://doi.org/10.1080/15502783.2025.2501063","url":null,"abstract":"<p><strong>Background: </strong>Caffeine's ergogenic potential in vertical jumping remains contested, particularly at dosages compliant with collegiate athletic regulations. The NCAA enforces a caffeine urinary threshold equivalent to ~5 mg/kg body mass, yet evidence supporting its efficacy in enhancing explosive performance among trained athletes is inconsistent. This study examined whether acute caffeine ingestion at this threshold improves squat jump (SJ) and countermovement jump (CMJ) performance in NCAA Division II student-athletes, while exploring sex-specific responses and trial-to-trial variability.</p><p><strong>Methods: </strong>Forty NCAA Division II athletes (18 females, 22 males; 21.3 ± 2.4 years) participated in a single-blind, randomized, crossover trial. Participants ingested 5 mg/kg caffeine or placebo, followed by SJ and CMJ testing on a force platform 60 minutes post-consumption. Three trials per jump type were retained to preserve intra-individual variance. Linear mixed-effects models (LMMs) assessed fixed effects of condition, sex, and trials, with random intercepts and slopes accounting for individual variability. A priori power analyses guided sample size determination, targeting sensitivity to detect small-to-medium effects (Cohen's f ≥ 0.2).</p><p><strong>Results: </strong>Caffeine elicited trivial, non-significant differences in SJ (β =  -0.24 cm, <i>p</i> = 0.646) and CMJ (β =  -0.71 cm, <i>p</i> = 0.183) heights compared to placebo. Males outperformed females in both SJ (Δ = 9.50 cm, <i>p</i> < 0.001) and CMJ (Δ = 11.30 cm, <i>p</i> < 0.001), though no condition-by-sex interactions emerged. Trial effects were observed, with SJ improving 2.31 cm (<i>p</i> < 0.001) and CMJ 1.05 cm (<i>p</i> = 0.014) from first to second attempts, suggesting warm-up or neuromuscular potentiation. High intraclass correlation coefficients (ICC = 0.76-0.85) underscored substantial interindividual variability. Models demonstrated robust fit (conditional R² = 0.86-0.92), with sufficient power to detect medium-to-large effects (f ≥ 0.25).</p><p><strong>Conclusions: </strong>A 5 mg/kg caffeine dose, compliant with NCAA thresholds, did not enhance vertical jump performance in habituated collegiate athletes, challenging prior assertions of its universal ergogenicity for ballistic tasks. While sex differences in baseline performance persisted, caffeine did not modulate these disparities, implicating neuromuscular and anthropometric factors as primary determinants. The absence of ergogenic effects aligns with NCAA safety-focused policies but highlights the need for personalized dosing strategies and research into higher doses, genetic variability, and hormonal influences. Future studies should integrate biomechanical metrics and controlled hormonal assessments to elucidate caffeine's nuanced role in anaerobic power sports.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2501063"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12054566/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143999382","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":"General and sport-specific nutrition knowledge and behaviors of adolescent athletes.","authors":"Ronald L Gibbs, Tyler Brian Becker","doi":"10.1080/15502783.2025.2477060","DOIUrl":"10.1080/15502783.2025.2477060","url":null,"abstract":"<p><strong>Introduction: </strong>Most youth do not meet national nutrition recommendations and overconsume high-calorie, low nutrient-dense foods. Adequate nutritional intake is crucial for growth and development. Nutrition practices play a key role in sports performance and recovery. Nutritional knowledge can affect eating patterns. However, there is limited research on general and sport-specific nutrition knowledge and behaviors of adolescent athletes.</p><p><strong>Purpose: </strong>To examine general and sport-specific nutrition knowledge and behaviors of adolescent athletes.</p><p><strong>Methods: </strong>Adolescent athletes were assessed on nutrition knowledge and general and sport-specific nutrition behaviors, including food group consumption, hydration practices, and sport supplement use. Gender differences in general and sport-specific nutrition behaviors were compared using a Mann-Whitney U test. Odds ratios and logistic regression, controlling for age, ethnicity, and years in sport participation were used to determine differences in correct responses between genders. Significance was set at the <i>p</i> < 0.05 level.</p><p><strong>Results: </strong>One hundred and ninety-four athletes (<i>n</i> = 63 male, <i>n</i> = 132 female, mean age = 14.9 ± 1.63 years) were assessed. Differences in nutrition behaviors were found in fruit, dairy, and sugary beverage consumption between genders. Male athletes were more likely to monitor hydration and use sports supplements. Both males and females scored less than 50% on both general and sport-specific knowledge questions.</p><p><strong>Conclusion: </strong>Adolescent athletes report lower than recommended food group consumption and lack knowledge of general and sport-specific nutrition information. Improvements in these areas can play a significant role in the health and performance of adolescent athletes.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2477060"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11894754/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586151","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":"Chronic low water intake is associated with altered exercise-induced oxidative stress and immune cell responses: a cross-sectional study.","authors":"Minju Sim, Wook Song, Eun Young Choi, Dong-Mi Shin, Chong-Su Kim","doi":"10.1080/15502783.2025.2551213","DOIUrl":"10.1080/15502783.2025.2551213","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Hydration status plays a critical role in modulating oxidative stress during exercise, which can influence physical performance and recovery. While the acute effects of hydration on exercise-induced oxidative stress are well-documented, the long-term impact of chronic water intake remains poorly understood. Therefore, this study aimed to investigate the relationship between chronic low water intake and exercise-induced oxidative stress, as well as changes in the phenotypic composition of peripheral immune cells.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;We assessed the usual plain water intake of the participants (&lt;i&gt;n&lt;/i&gt; = 26; 19-29 years) using a questionnaire and classified them as habitually high-water drinkers (HIGH; &lt;i&gt;n&lt;/i&gt; = 16; mean plain water intake = 1.22 ± 0.19 L/d) or low-water drinkers (LOW; &lt;i&gt;n&lt;/i&gt; = 10; 0.41 ± 0.10 L/d). We conducted a maximal graded exercise test and investigated whether the extent of exercise-induced oxidative stress and immunological changes differed depending on the habitual water intake. Free radical production before and after the exercise test was assessed using serum concentrations of reactive oxygen metabolites (ROMs). The antioxidant capacity to eliminate free radicals was assessed using the serum biological antioxidant potential (BAP). We profiled peripheral blood mononuclear cells (PBMCs; CD4&lt;sup&gt;+&lt;/sup&gt;, CD8&lt;sup&gt;+&lt;/sup&gt;, CD20&lt;sup&gt;+&lt;/sup&gt;, CD14&lt;sup&gt;+&lt;/sup&gt;, CD11b&lt;sup&gt;+&lt;/sup&gt;, and Annexin V&lt;sup&gt;+&lt;/sup&gt;) using fluorescence-activated cell sorting.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;At baseline, the LOW group showed higher concentrations of serum ROMs than the HIGH group (&lt;i&gt;p&lt;/i&gt; = 0.033). In a maximal graded exercise test, both groups showed comparable performance parameters including peak heart rate, VO&lt;sub&gt;2&lt;/sub&gt;max, and exercise duration. However, the biochemical responses differed markedly: serum BAP significantly increased in the HIGH group but remained unchanged in the LOW group (&lt;i&gt;p&lt;/i&gt; = 0.030). Furthermore, the LOW group showed a larger increase in PBMC apoptosis than the HIGH group, both in absolute cell number and percentage (&lt;i&gt;p&lt;/i&gt; = 0.031 and &lt;i&gt;p&lt;/i&gt; = 0.034, respectively). The LOW group also showed differential PBMC subset frequencies, with greater CD11b&lt;sup&gt;+&lt;/sup&gt; cell recruitment (&lt;i&gt;p&lt;/i&gt; = 0.015) and less pronounced CD14&lt;sup&gt;+&lt;/sup&gt; cell reduction compared to the HIGH group (&lt;i&gt;p&lt;/i&gt; = 0.050).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Habitual low water intake was associated with elevated concentrations of free radical by-products in the resting state and impaired antioxidant capacity during acute exercise stress. In response to exercise stress, impaired redox balance in low-water drinkers resulted in accelerated cellular damage and increased myeloid cell recruitment. These findings highlight the importance of maintaining adequate habitual water intake to cope with exercise-induced oxidative stress and prevent excessive cellular stress responses.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Clini","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2551213"},"PeriodicalIF":3.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12409870/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144958726","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":"Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance.","authors":"Rouzbeh Razazan, Mohammad Hemmatinafar, Babak Imanian, Nima Jahaniboushehri, Rasoul Rezaei, Gholamhossein Nazemzadegan","doi":"10.1080/15502783.2025.2564238","DOIUrl":"10.1080/15502783.2025.2564238","url":null,"abstract":"<p><strong>Background: </strong>Caffeine is a well-known ergogenic aid that can enhance physical and cognitive performance. However, it often induces side effects, such as anxiety and overstimulation, which can be problematic in high-pressure sports like wrestling. L-theanine, a non-stimulant amino acid found in tea, may help mitigate these effects by promoting a calm yet focused mental state. This study aimed to investigate the acute effects of caffeine, L-theanine, and their combination on physical performance, cognitive function, and anxiety in elite male wrestlers.</p><p><strong>Methods: </strong>In a double-blind, placebo-controlled, crossover design, 12 elite male wrestlers (21.8 ± 2.1 years) completed four test sessions under randomized conditions: placebo (PLA), caffeine (CAF; 3 mg/kg), L-theanine (THE; 3 mg/kg), and caffeine + L-theanine (CAF+THE; 3 mg/kg each). After 60 minutes, athletes performed the wall-squat test, vertical jump height (VJH), medicine ball throw (MBT), handgrip strength, and the Specific Wrestling Fitness Test (SWFT). Cognitive function was assessed pre- and post-SWFT using a computerized Stroop test. Anxiety was assessed using the State-Trait Anxiety Inventory (STAI), and side effects were recorded.</p><p><strong>Results: </strong>CAF+THE outperformed PLA in wall-squat time (<i>p</i> = 0.001), MBT (<i>p</i> = 0.005), VJH (<i>p</i> = 0.011), and grip strength (<i>p</i> = 0.004). SWFT throw count was highest in CAF+THE versus all other conditions (<i>p</i> < 0.001). Post-SWFT Stroop reaction time was faster in CAF+THE than PLA (<i>p</i> = 0.004) and THE (<i>p</i> = 0.036), and accuracy was also higher (<i>p</i> = 0.009 vs PLA). CAF alone increased state anxiety compared to PLA (<i>p</i> = 0.021), while CAF+THE reduced anxiety to below placebo levels (8% incidence vs 33%). Trait anxiety was lower in CAF+THE compared to CAF (<i>p</i> = 0.018). The prevalence of caffeine-induced tachycardia (92%) was notably reduced under CAF+THE (17%).</p><p><strong>Conclusion: </strong>CAF+THE (3 mg/kg each) enhances elite wrestlers' strength, endurance, cognitive speed, and accuracy while reducing anxiety and physiological side effects commonly associated with caffeine alone. This combination represents a safe, practical supplement strategy for combat sports athletes who must maintain explosive performance and mental control under stress. Coaches are encouraged to trial CAF+THE protocols during training to personalize timing and dosage.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2564238"},"PeriodicalIF":3.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12456047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145113565","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":"Similar effects between animal-based and plant-based protein blend as complementary dietary protein on muscle adaptations to resistance training: findings from a randomized clinical trial.","authors":"Martin Hindermann Santini, Alice Erwig Leitão, Bruna Caruso Mazzolani, Fabiana Infante Smaira, Mariana Silva Camargo de Souza, Andrea Santamaria, Bruno Gualano, Hamilton Roschel","doi":"10.1080/15502783.2025.2568047","DOIUrl":"https://doi.org/10.1080/15502783.2025.2568047","url":null,"abstract":"<p><strong>Background: </strong>Recent evidence suggests that both animal and plant proteins support strength and hypertrophy gains when paired with resistance training and adequate protein intake. The purpose of this study was to investigate the effects of supplementary protein source (blend of plant-based [PLNT] vs. animal based [ANML]) to habitual diet on changes in muscle mass and strength in healthy young men undertaking resistance training.</p><p><strong>Methods: </strong>Forty-four young untrained males were recruited for this study. Subjects were randomly allocated into two groups, and consumed three 15-g daily doses (45 g. d-¹ total) of either a mixed plant- (i.e.; soy and pea) or animal-based (i.e.; whey) protein in drink form as a supplementary source of protein in their main meals of the day (i.e.; breakfast, lunch, and dinner) for 12 weeks combined with a 3 times/week linear periodized and supervised resistance training program. Prior to the start of the trial, three (2 nonconsecutive weekdays and 1 weekend day) 24-h dietary recalls were collected to determine baseline habitual protein intake and were repeated during the protocol at weeks 4, 8, and 12. Muscle cross-sectional area (CSA, via ultrasonography imaging) determination, body composition (via dual emission x-ray absorptiometry, DXA), and lower-body maximum dynamic strength (1RM, via leg press) were assessed at baseline (PRE) and after 12 weeks of intervention (POST).</p><p><strong>Results: </strong>Both groups showed significant (all <i>p</i> < 0.0001) PRE-to-POST increases in whole-body lean mass (PLNT: 2.4 kg ±1.6, ANML: 2.5 kg ±3.9), appendicular lean mass (PLNT: 1.2 kg ±0.2; ANML: 1.8 kg ±0.2) and leg lean mass (PLNT: 0.9 kg ±0.2; ANML: 1.3 kg ±0.2), vastus lateralis mCSA (PLNT: 0.9 cm² ±0.2; ANML: 1.3 cm² ±0.2) and leg-press 1RM (PLNT: 64 kg ±7.8; ANML: 63 kg ±7.5), with no between-group differences for any of the variables (all <i>p</i> > 0.05).</p><p><strong>Conclusion: </strong>Complementing dietary protein intake with either a blend of plant- or an animal-based protein similarly supported resistance training-induced muscle adaptations.</p><p><strong>Trial registration: </strong>Distinct Sources of Supplementary Protein in the Resistance Exercise Training-induced Adaptations, NCT05710614, 08/01/2023.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2568047"},"PeriodicalIF":3.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251765","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":"Hypercaloric 16:8 time-restricted eating during 8 weeks of resistance exercise in well-trained men and women.","authors":"Daniel T Blake, Cody Hamane, Chelscie Pacheco, Menno Henselmans, Grant M Tinsley, Pablo Costa, Jared W Coburn, Thomas Campidell, Andrew J Galpin","doi":"10.1080/15502783.2025.2492184","DOIUrl":"https://doi.org/10.1080/15502783.2025.2492184","url":null,"abstract":"<p><strong>Background: </strong>The effectiveness and practicality of time-restricted eating (TRE) when trying to maximize muscle mass and strength is unclear. Thus, we examined the effects of a hypercaloric 16:8 TRE approach during supervised progressive resistance exercise.</p><p><strong>Methods: </strong>Seventeen healthy and well-trained men (<i>n</i> = 10) and women (<i>n</i> = 7) were randomly assigned to TRE or control (FED). Both groups consumed a 10% hypercaloric high-protein (2.2 g/kg/d) diet and performed supervised resistance exercise 4× per wk for 8 wk. TRE consumed all calories within an 8 h window starting at least 1 h post-exercise, while FED consumed the same number of calories throughout the day.</p><p><strong>Results: </strong>Eating windows were significantly different (TRE: 7.9 ± 0.1 h vs. FED: 13.2 ± 0.6 h). Calorie, carbohydrate, fat, and protein intake did not differ statistically between groups. Total exercise volume was significantly lower in TRE than FED (6,960 ± 287 vs. 7,334 ± 289 repetitions), as were subjective daily energy ratings (week 4 = -1.41; <i>p</i> = 0.04, week 8 = -1.04; <i>p</i> = 0.06). Both groups increased maximal upper and lower body strength (1RM) and muscular endurance (ME); however, gains in squat 1RM were 4.0 ± 1.9 kg lower in TRE (<i>p</i> = 0.05). Both groups increased fat-free mass similarly (TRE: 2.67 kg; FED: 1.82 kg, <i>p</i> = 0.04), but FED added 1.4 ± 0.6 kg more fat mass (<i>p</i> = 0.04). Subjective mood and sleep ratings did not change in either group.</p><p><strong>Conclusions: </strong>16:8 TRE is viable during periods of muscle size, strength, and endurance development in well-trained young men and women when engaging in progressive resistance exercise and eating in a caloric surplus with adequate protein. However, the differences in total training volume, squat 1RM, fat mass accumulation, and energy are notable and practically relevant. These findings should be considered within the broader context of an individual's goals, lifestyle, preferences, and exercise demands.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2492184"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12006946/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144016636","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}