Journal of the International Society of Sports Nutrition最新文献

{"title":"No effects of caffeine on cycling to exhaustion and perceptual responses in non-caffeine-restricted subjects.","authors":"Matthias Weippert, Martin Behrens, Martin Schlegel, Tom Schröder, Moritz Tillmann, Nelly Rühe, Robert Römer, Anett Mau-Möller, Sven Bruhn","doi":"10.1080/15502783.2025.2534131","DOIUrl":"10.1080/15502783.2025.2534131","url":null,"abstract":"<p><strong>Introduction: </strong>Caffeine has been shown to improve endurance performance probably primary due to its pharmacological effects in the central nervous system modifying, among others, the perceptual responses during exercise. However, most studies proving the performance-enhancing effects of caffeine utilized an experimental caffeine restriction phase prior to the measurement sessions. Therefore, the effects of 2.5 and 6 mg*kg^-1 oral caffeine ingestion on endurance performance, perceptual, affective, and cognitive responses during exercise, as well as time perception, were investigated in participants following their normal \"ad libitum\" daily diet.</p><p><strong>Methods: </strong>Two double-blinded, randomized placebo-controlled cross-over studies were performed to test the effect of 2.5 (<i>N</i> = 35, age: 23.3 ± 3.5 years, habitual caffeine consumption of 106 ± 89 mg*day^-1) and 6.0 mg*kg^-1 (<i>N</i> = 21, age: 21.2 ± 2.3 years, habitual caffeine consumption of 87 ± 64 mg*day^-1) oral caffeine ingestion on time to exhaustion (TTE), perceived fatigue, perceptual-discriminatory (effort perception, physical strain), affective-motivational (affective valence, arousal, dominance, motivation, boredom), and cognitive-evaluative responses (decisional conflict, attentional focus) as well as time perception (time production and estimation) and heart rate during cycling at 65% peak power. Participants were low-to-moderate caffeine consumers (one participant in each study reported no habitual caffeine intake) and asked to follow their regular \"ad libitum\" diet without any restrictions regarding caffeinated beverages and/or food during the studies.</p><p><strong>Results: </strong>Neither a dose of 2.5 nor of 6.0 mg*kg^-1 was found to be superior to placebo with respect to TTE, perceived fatigue, the perceptual-discriminatory, affective-motivational, and cognitive-evaluative responses to exercise, as well as time perception.</p><p><strong>Conclusion: </strong>Both dosages of caffeine had no effect on TTE, perceived fatigue, perceptual-discriminatory, affective-motivational, and cognitive-evaluative responses to exercise, as well as on time perception and heart rate in low-to-moderate caffeine consumers without a prior experimental caffeine restriction phase. The findings suggest that caffeine´s positive effects on endurance performance and perceptual responses to exercise found in previous studies might be partly explained by the reversal of adverse effects induced by a prior caffeine restriction phase.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2534131"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144698943","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":"International society of sports nutrition position stand: nutrition and weight cut strategies for mixed martial arts and other combat sports.","authors":"Anthony A Ricci, Cassandra Evans, Charles Stull, Corey A Peacock, Duncan N French, Jeffery R Stout, David H Fukuda, Paul La Bounty, Douglas Kalman, Andrew J Galpin, Jaime Tartar, Sarah Johnson, Richard B Kreider, Chad M Kerksick, Bill I Campbell, Aaron Jeffery, Chris Algieri, Jose Antonio","doi":"10.1080/15502783.2025.2467909","DOIUrl":"10.1080/15502783.2025.2467909","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Following an extensive literature review, the International Society of Sports Nutrition (ISSN) has developed an official position on nutritional and weight cut strategies for combat sports. The type of combat sport, length of the fight camp, and time between weigh-in and competition are factors influencing nutritional and weight cut strategies. The following 16 points constitute the Position Statement of the Society; the Research Committee has approved them. 1. Combat sports have differing weight categories, official weigh-in times, and competition frequencies, influencing the nutritional and weight cut strategies for training and competition. 2. As the duration of a combat match increases, &gt;4 min, contribution of the aerobic system can rise to &gt;70%, yet anaerobic alactic pathways and anaerobic glycolytic pathways support high-output bursts. 3. During the off camp/general preparation phase, athletes should maintain a weight ranging 12% to 15% above the weight division requirement. 4. Supplements including creatine, beta-alanine, beta-hydroxy-beta-methylbutyrate, and caffeine have been shown to enhance performance and/or recovery during preparation phases, competition, and post-competition. 5. During fight camp, strategic decreases in calorie intake are necessary for an efficient longitudinal weight descent. Individual caloric needs can be determined using indirect calorimetry or validated equations such as Mifflin St. Jeor or Cunningham. 6. Protein should be prioritized during longitudinal weight descents to preserve lean body mass, and the timely delivery of carbohydrates supports training demands. Macronutrients should not drop below the following: carbohydrates 3.0-4.0 g/kg, protein 1.2-2.0 g/kg, and fat 0.5 to 1.0 g/kg/day. 7. Suitable losses in body mass range from 6.7% at 72 h, 5.7% at 48 h, and 4.4% at 24 h, prior to weigh-in. 8. Sodium restriction and water loading are effective for inducing polyuria and acute water loss. 9. During fight week, water-bound glycogen stores can be depleted through exercise and carbohydrate restriction, facilitating a 1% to 2% loss in body mass, with equivalent losses from a low-fiber intake of &lt;10 g/day for 4 days. 10. During fight week, acute water loss strategies, including sauna, hot water immersion, and mummy wraps, can be used effectively with appropriate supervision (optimally ~2-4% of body mass within 24 h of weigh-in). 11. Post-weigh-in, rapid weight gain strategies are utilized to recover lost body fluid/mass before competition with the intent of gaining a competitive advantage. 12. Oral rehydration solutions (1 to 1.5 liters/h) combined with a sodium range of 50-90 mmol/dL should take precedence immediately post-weigh-in. 13. Fast-acting carbohydrates at a tolerable rate of ≤ 60 g/h should follow oral rehydration solutions. Post weigh-in intake of fiber should be limited to avoid gastrointestinal distress. 14. Post-weigh-in carbohydrate intake at 8-12 g/kg may be appropriate for combat athlet","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2467909"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11894756/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586152","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":"Macronutrient requirements and intake by professional male rugby players.","authors":"Maryke Meyer, Elmine du Toit, Riette Nel, Derik Coetzee","doi":"10.1080/15502783.2025.2479709","DOIUrl":"10.1080/15502783.2025.2479709","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Rugby union is a high-contact team sport where professional rugby players are exposed to considerable training and game loads in pre-season and in-season. Some studies have shown that rugby players' dietary intake remains inadequate for the three macronutrients (carbohydrates [CHO], proteins and fats) required for optimal performance. This study aimed to describe the macronutrient intake of professional male rugby players at Zebre Rugby Club in Parma, Italy, during in-season, and to compare players' macronutrient intake to international recommendations.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Thirty-four professional male rugby players participated in the cross-sectional study. A self-developed questionnaire, a food frequency questionnaire and food records (on training and competition days and off day) were used to investigate players' macronutrient intake. Anthropometric measurements were obtained using the International Society for the Advancement of Kinanthropometry (ISAK) standardized techniques. Descriptive statistics were calculated, and associations were investigated using chi-square, Fisher's exact and Wilcoxon rank tests as applicable.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The players' median age was 25.8 years (range 20.6-33.0 years) and 47.5% were Italian. Most players (64.7%) held forward positions and had a median of 5 years (range 2-14 years) of professional experience. More than 75.0% of players lived with a spouse or partner and 30.3% earned between 4 000-4 999 euros per month. The median body weight and height of players were 106.9 kg and 186.3 cm, respectively. The forwards weighed heavier (&lt;i&gt;p&lt;/i&gt; &lt; 0.0001) than the backs, which was expected due to positional demands, with no significant difference in height distribution. The median body mass index (&lt;i&gt;p&lt;/i&gt; &lt; 0.0001), waist circumference (&lt;i&gt;p&lt;/i&gt; &lt; 0.001) and waist-to-height ratio (&lt;i&gt;p&lt;/i&gt; &lt; 0.03) of forwards were higher than the backs. Additionally, the median body fat percentage of all players exceeded the international recommendation of 8-17% for rugby union players. The American College of Sports Medicine (ACSM), International Olympic Committee (IOC) and International Society of Sports Nutrition (ISSN) recommend an intake of 5.0-8.0 g/kg body weight (BW)/day CHO, 1.5-2.0 g/kg BW/day proteins and 20-35% total energy (TE) from fats for rugby players. The overall median intake of the three-day food records for all the players was 2.7 g/kg BW CHO, 1.7 g/kg BW protein and 35.1% TE from fat. On each of the three reported days, 90.0% of players' CHO intake fell below the recommended range, with almost all players (&gt;90.0%) consuming less than the recommended amount of carbohydrates and almost 30.0% of players consuming below the recommended amount of protein on competition day. At least 50.0% of players' protein and fat intake was within the recommended range on each of the three reported days.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;The study's findings can assist","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2479709"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11921163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143657537","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 carbohydrate timing on glucose metabolism and substrate oxidation following high-intensity evening aerobic exercise in athletes: a randomized controlled study.","authors":"Stig Mattsson, Fredrik Edin, Jonny Trinh, Peter Adolfsson, Johan Jendle, Stefan Pettersson","doi":"10.1080/15502783.2025.2494839","DOIUrl":"https://doi.org/10.1080/15502783.2025.2494839","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;The study aimed to investigate the impact of nutrient timing in relation to evening exercise. Specifically, it examined the effects of pre- or post-exercise carbohydrate (CHO) ingestion on glucose metabolism, glucose regulation, and overall substrate oxidation in well-trained athletes during and after physical exercise (PE), spanning the nocturnal period and the subsequent morning.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Ten male endurance cyclists participated in the study. The initial assessments included body composition measurements and an incremental cycle test to determine maximal oxygen uptake (&lt;math&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mover&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;O2 max) and maximum power output (Wmax). Following this, participants underwent a control (rest previous day) oral glucose tolerance test (OGTT) and a familiarization exercise trial that had two objectives: (1) to establish the appropriate amount of CHO to use in the pre- or post-exercise drink during the experimental trials, and (2) to familiarize participants with the equipment and study protocol. In the three days prior to both the control and experimental trials, participants followed a standardized, individualized diet designed to meet their energy needs. During the experimental trials, participants completed two separate evening exercise sessions (50 min@70%Wmax +  ~24 min time-trial (TT)) with either pre- or post-exercise CHO ingestion (253 ± 52 g), matching the CHO oxidized during exercise. The CHO drink and a volume-matched placebo (PLA) drink (containing no energy) were randomly assigned to be consumed two hours before and directly after the experimental exercise sessions. Post-exercise nocturnal interstitial glucose levels (24:00-06:00) were continuously monitored, and a 120-min OGTT was conducted the following morning to assess substrate oxidation rates and glucose control.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Pre-exercise CHO intake significantly lowered capillary glucose levels during steady-state exercise (mean difference 0.41 ± 0.27 mmol/L, &lt;i&gt;p&lt;/i&gt; = 0.001) without affecting perceived exertion and TT-performance. No difference was observed in nocturnal glucose regulation (00:00-06:00) regardless of whether CHO was consumed before or after exercise. Post-exercise CHO ingestion reduced glucose tolerance during the OGTT compared to the iso-caloric pre-exercise CHO intake (mean difference 0.76 ± 0.21 mmol/L, &lt;i&gt;p&lt;/i&gt; = 0.017). However, a post-exercise CHO intake improved respiratory exchange ratio/metabolic flexibility (MetF) significantly. Enhanced MetF during the first OGTT hour after post-exercise CHO ingestion resulted in 70% and 91% higher CHO oxidation compared to pre-exercise CHO and control, respectively (&lt;i&gt;p&lt;/i&gt; ≤ 0.029). Average 120-min OGTT fat oxidation rates were higher with both pre- and post-exercise CHO ingestion compared to control (&lt;i&gt;p&lt;/i&gt; ≤ 0.008), with no difference between pre- and post-exercise CHO intake.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Co","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2494839"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12016275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017268","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":"Dietary supplement use and knowledge among athletes: prevalence, compliance with AIS classification, and awareness of certification programs.","authors":"Anna Broniecka, Aleksandra Sarachman, Aleksandra Zagrodna, Anna Książek","doi":"10.1080/15502783.2025.2496450","DOIUrl":"https://doi.org/10.1080/15502783.2025.2496450","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;The use of dietary supplements is widespread among athletes, with intake influenced by factors such as sport-discipline, competitive level, and gender. The Australian Institute of Sport (AIS) has categorized supplements based on scientific evidence regarding their efficacy and safety. Despite extensive global research on dietary supplement use among athletes, data on Polish athletes remain limited. Therefore, this study aimed to evaluate supplement use among Polish athletes, considering their competitive level and gender. Additionally, it assessed whether athletes select supplements in accordance with the AIS classification and examined their awareness of supplement certification programs.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;This cross-sectional study included 659 Polish athletes (309 women, 350 men) from various sports, representing both professional (57.7%) and nonprofessional (42.3%) levels. An online questionnaire was used to assess dietary supplement consumption, sources of information regarding supplementation, and knowledge of anti-doping and supplement certification programs. Supplement use was categorized according to the AIS classification (Groups A - D). Statistical analyses, including chi-square tests and Mann - Whitney U tests, were conducted to evaluate differences between professional and nonprofessional athletes, as well as between male and female participants.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;A high prevalence of dietary supplement use (91.1%) was observed among Polish athletes, with no significant differences between professional (95.8%) and nonprofessional (94.3%) athletes or between men (92.0%) and women (90.0%). The most frequently consumed supplements were sports drinks (63.9%), electrolyte supplements (51.6%), and isolated protein supplements (54.6%), vitamin D (71.6%), vitamin C (59.8%), with significantly higher intake among professional athletes. Male athletes were more likely than females to consume caffeine (&lt;i&gt;p&lt;/i&gt; &lt; 0.001), creatine (&lt;i&gt;p&lt;/i&gt; &lt; 0.001), and β-alanine (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). Melatonin use was significantly higher among professionals (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). Awareness of WADA regulations was moderate (72.7%), but knowledge of supplement certification programs was low, with only 18.2% of professional athletes familiar with Informed Sport, and 10.7% with the Cologne List. Social media was the most common source of supplement information (41.9%), while only 17.6% of athletes consulted qualified specialists in sports nutrition and supplementation area.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;This study highlights the widespread use of dietary supplements among Polish athletes, irrespective of competitive level or gender. While many athletes select supplements from AIS Group A, their knowledge of AIS classification and supplement certification programs remains limited. The high reliance on social media for supplement information, combined with the lack of professional guidance, underscores the ","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2496450"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12016268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144010943","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":"Pre-workout multi-ingredients or carbohydrate alone promote similar resistance training outcomes in middle-aged adults: a double-blind, randomized controlled trial.","authors":"Joel Puente-Fernández, Eneko Larumbe-Zabala, Justin Roberts, Fernando Naclerio","doi":"10.1080/15502783.2025.2519515","DOIUrl":"10.1080/15502783.2025.2519515","url":null,"abstract":"<p><strong>Background: </strong>Pre-workout multi-ingredients are designed to enhance energy levels and acutely increase exercise performance. This study compared the effectiveness of ingesting an admixture providing caffeinated ingredients and plant-based protein enriched with amino acids versus carbohydrates alone on body composition, hypertrophy and physical performance.</p><p><strong>Methods: </strong>Forty-three middle-aged physically active individuals (26 peri- and post-menopausal females and 17 males) completed the study after being randomly assigned to one of the following intervention groups: pre-workout (PREW <i>n</i> = 24, 54 ± 4 years, body mass 77.6 ± 16.0 kg) or a carbohydrate-only comparator (COMP <i>n</i> = 19, 52 ± 4 years, body mass 80.6 ± 16.0 kg). Measurement of fat and fat-free mass (via plethysmography), waist and hip circumferences, muscle thickness (via ultrasound), strength, power output and muscle endurance performance were collected before and after a 6-week resistance training programme performed 3 times per week. Treatment consisted of ingesting 30g of the assigned supplement, mixed with 400mL of plain water, 15min before each workout session.</p><p><strong>Results: </strong>Both groups significantly (<i>p</i> < 0.05) reduced fat mass (mean ± SD) (PREW -1.4 ± 1.6 kg; COMP -1.0 ± 1.5 kg), increased fat-free mass (PREW +0.9 ± 1.1 kg; COMP + 0.8 ± 0.9 kg); vastus lateralis (PREW +0.2 ± 0.2 cm; COMP + 0.1 ± 0.6 cm), and elbow flexors (PREW +0.5 ± 0.3 cm; COMP + 0.4 ± 0.2 cm) muscle thickness. Only the PREW group showed a significant reduction in the waist circumference (-1.8 ± 1.8 cm, <i>p</i> < 0.01). However, no significant differences between groups (PREW vs. COMP) were identified at post-intervention. Isometric force, countermovement jump, medicine ball throw, and upper and lower body muscle endurance performance improved (<i>p</i> < 0.05) for both treatments, with no difference between groups.</p><p><strong>Conclusion: </strong>Except for waist circumference reduction, ingesting a pre-workout vegan protein-based caffeinated supplement promotes no further resistance training benefits in middle-aged individuals.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2519515"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12168407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144285109","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":"Predictors of caffeine consumption patterns in high school athletes.","authors":"Eamonn M O'Connell, Disa L Hatfield, Amanda Stors, Steven A Cohen","doi":"10.1080/15502783.2025.2525378","DOIUrl":"10.1080/15502783.2025.2525378","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study was to examine caffeine consumption and the factors that affect caffeine use in high school athletes.</p><p><strong>Methods: </strong>Three hundred and ninety-four Rhode Island high school athletes (age: 16.8 ± 1.27 years) completed a cross-sectional online survey to assess caffeine consumption. A multivariate logistic regression analysis and binary logistic regression were performed to characterize associations between use and nonuse and the independent variables of ethnicity, grade, sex, and sport played. 95% confidence intervals (CI) were calculated for all models. Statistical significance was set to <i>p</i> ≤ 0.05 for all analysis.</p><p><strong>Results: </strong>Fifteen point five percent of the variance in caffeine use was related to ethnicity, grade, and sex(R² = 0.155), with significant results for each variable. A majority of female athletes consumed caffeine (67.4%), compared to male athletes (37.8%) (<i>p</i> < 0.001). Athletes identifying as Caucasian reported significantly more caffeine use (55.9%), compared to athletes from underrepresented backgrounds (32.6%) (<i>p</i> < 0.001). Caffeine use was significantly different across grades, where 30.6% of 9th graders, 49.2% of 10th graders, 55.2% of 11th graders, and 49.2% of 12th graders reported caffeine use (<i>p</i> = 0.049). Coffee (51%) and energy drinks (43%) were the primary sources of caffeine consumption. Dance, cheerleading, and gymnastics participants were more than ten times as likely to consume caffeine compared to other sports (95% CI [2.28, 48.94], Exp (β) = 10.57).</p><p><strong>Conclusion: </strong>Caffeine use in young athletes is related to factors including sex and ethnicity. Given the prevalence of use, young athletes, coaches, and parents/guardians should be educated on the risks and benefits of caffeine use. Future research should focus on the potential benefits of caffeine use to athletic performance verses possible side effects in this population.</p><p><strong>Supported by: </strong>The Clean Competition Grant from the Rhode Island Foundation.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2525378"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207778/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528433","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":"Low-dose caffeine enhances cognitive processing but not physical performance in fatigued taekwondo athletes: a randomized crossover trial.","authors":"Alisa Nana, Papatsorn Ramyarangsi, Luksika Jamwai, Poomwut Hiranphan, Vorasith Siripornpanich, Amornpan Ajjimaporn","doi":"10.1080/15502783.2025.2526094","DOIUrl":"10.1080/15502783.2025.2526094","url":null,"abstract":"<p><strong>Background: </strong>Caffeine is commonly used to combat fatigue and enhance both cognitive and physical performance. However, its effects on neurophysiological responses and sport-specific performance following fatigue induction remain unclear, particularly in combat sports such as Taekwondo. This study investigated the effects of a 200 mg caffeine dose on physiological markers, electroencephalographic (EEG) brainwave activity, auditory P300 event-related potentials (ERPs), and Taekwondo-specific performance following combined mental and physical fatigue.</p><p><strong>Methods: </strong>Thirteen male Taekwondo athletes participated in a randomized, double-blind, crossover study with caffeine (CAF) and placebo (PLA) conditions. Measurements were taken at baseline (pre-supplementation), 30 minutes post-supplementation (post-Sup), and after fatigue induction (post-I). Physiological parameters (heart rate, blood glucose, blood lactate, and ratings of perceived exertion), EEG brainwave activity during resting eyes-open conditions, auditory P300 ERPs, and Taekwondo-specific agility (TSAT) were assessed at all time points.</p><p><strong>Results: </strong>Caffeine significantly reduced delta wave power at frontal and parieto-occipital sites at post-Sup (<i>p</i> < 0.05), indicating decreased cortical drowsiness; however, this effect was not sustained at post-I (<i>p</i> > 0.05). P300 amplitude significantly increased in the CAF condition compared to PLA from post-Sup to post-I at the central and parietal electrode sites (<i>p</i> < 0.05), while P300 latency remained unchanged (<i>p</i> > 0.05). No significant differences were observed in reaction time, accuracy, or error rate in the auditory oddball task or TSAT performance across conditions (<i>p</i> > 0.05). Similarly, physiological parameters remained unchanged between groups (<i>p</i> > 0.05).</p><p><strong>Conclusion: </strong>A single 200 mg dose of caffeine reduced central fatigue and enhanced cognitive processing, as reflected by suppressed delta wave activity at post-Sup and increased P300 amplitude at post-I. However, caffeine did not influence physiological responses or Taekwondo-specific performance. These findings suggest that low-dose caffeine primarily benefits cognitive function rather than physical performance in combat sports. Future studies should explore dose-response relationships and individual variability in caffeine metabolism to optimize its application in competitive settings.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2526094"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12207766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528432","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":"Exercise with fasting or isotonic drink? A randomized controlled trial in youth elite basketball players.","authors":"Petra Márton, Luca Kata Bátai, Titanilla Takács, Emese Csulak, Anna Réka Kiss, Bence Kopper, Liliána Erzsébet Szabó, Dorottya Balla, Iván Petrov, Lilla Lázár, Hajnalka Vágó, Béla Merkely, Nóra Sydó","doi":"10.1080/15502783.2025.2528533","DOIUrl":"10.1080/15502783.2025.2528533","url":null,"abstract":"<p><strong>Background: </strong>Pre-exercise carbohydrate intake is known to influence performance; however, data describing their effect on cardiorespiratory parameters is scarce. This study aimed to assess the effects of isotonic drink consumption on cardiopulmonary exercise test (CPET) parameters in elitemale youth basketball players.</p><p><strong>Methods: </strong>The athletes were randomized into a fasting (400 ml mineral water) and an isotonic drink (400 ml 7% isotonic solution) group respectively, and consumed the drinks 30 minutes before the CPET. Pre-, peak- and post-CPET glucose levels were measured. Borg and lactate were assessed every 2 minutes during the test.</p><p><strong>Results: </strong>Seventy-one athletes (age: 15.9 ± 1.8 years) were included in the study. The isotonic drink group had higher pre- and post-CPET glucose levels (<i>p</i> < 0.05). They reported a lower Borg scale at the 2nd, 6th, and 10th minutes (<i>p</i> < 0.05), while their lactate levels were lower at the 14th minute (<i>p</i> < 0.05). Regression analysis showed that fasting was associated with higher Borg scale ratings (β-coefficient: 0.72, <i>p</i> < 0.001) and increased lactate accumulation over time (β-coefficient: 0.13, <i>p</i> = 0.01). No difference was found in exercise duration or maximal aerobic capacity.</p><p><strong>Conclusions: </strong>Single-dose isotonic drink consumption before CPET reduces perceived exertion and moderates lactate accumulation, which may suggest a beneficial effect during the exercise test.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2528533"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12239237/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144584238","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":"Association between caffeine intake and fat free mass index: a retrospective cohort study.","authors":"Ya-Lan Tian, Xin Liu, Meng-Yao Yang, Yu-Han Wu, Fu-Qiang Yin, Zhen-Tong Zhang, Chao Zhang","doi":"10.1080/15502783.2024.2445607","DOIUrl":"https://doi.org/10.1080/15502783.2024.2445607","url":null,"abstract":"<p><strong>Background: </strong>Caffeine, identified as a central nervous system stimulant in foods, beverages (coffee, tea, chocolate), and medications, has been focused on its ergogenic properties, enhancing physical performance. The aim of this study was to investigate the association between the caffeine intake (from coffee) and fat-free mass index (FFMI).</p><p><strong>Materials and methods: </strong>We carried out a cohort study that included 3,466 women and 3,145 men aged ≥20 years who were intaking caffeine. Caffeine intake from coffee were obtained from two 24-hour dietary recall interviews. The FFMI was calculated as FFM (kg) divided by height in m². The caffeine intake was classified into quartiles and combined into 4 groups. Multiple linear regression model analysis and multiple logistic regression model analysis were used to assess associations between the caffeine and FFMI adjusted for potential confounders.</p><p><strong>Results: </strong>Among the 2,427 participants, males accounted for 52.4%, and females 47.6%. In multiple linear regression model, Model 1 (unadjusted Model (<i>p</i> = 0.041)) and Model 2 (adjusted for age, race, and BMI (<i>p</i> = 0.006)) in women showed a significant relationship between caffeine intake and FFMI. In multivariable models, caffeine intake and FFMI were significantly different (<i>p</i> < 0.05). In sex subgroups, among females, each quartile of caffeine intake was positively correlated with FFMI levels in the average FFMI group in Model 3 (<i>p</i> < 0.001). In age subgroups, each quartile of caffeine intake was positively correlated with FFMI levels in the average FFMI group in Model 3 for individuals aged 20-40 (<i>p</i> = 0.039) and those aged above 40 (<i>p</i> = 0.016). In drinking status subgroups, if they drunk alcohol, each quartile was positively correlated with FFMI levels in the average FFMI group in Model 3 (<i>p</i> < 0.001).</p><p><strong>Conclusion: </strong>Caffeine intake was mainly positively associated with FFMI, especially in women with above levels of FFMI. Longitudinal studies and randomized controlled trials are needed to establish causality and provide evidence-based recommendations regarding caffeine intake to optimize muscle health.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2445607"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871850","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}