International journal of sport nutrition and exercise metabolism最新文献

UCI Sports Nutrition Project: Considerations and Applications for the Use of Sports Foods and Supplements to Improve Performance in Cycling. UCI运动营养项目：使用运动食品和补品提高自行车运动成绩的考虑和应用。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-12-31 Print Date: 2026-05-01 DOI: 10.1123/ijsnem.2025-0111

Jamie Whitfield, Brendan Egan, Juan Del Coso, Wim Derave, Bryan Saunders, Louise M Burke

引用次数: 0

Influence of Guideline-Based Carbohydrate Intake on Training Adaptations, Health, and Sleep in Female Rugby Athletes: An Exploratory Study. 基于指南的碳水化合物摄入对女性橄榄球运动员训练适应、健康和睡眠的影响：一项探索性研究。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-09-04 DOI: 10.1123/ijsnem.2026-0112

Rebekka Frazer, Christopher D Askew, Amy-Lee Bowler, Louise M Burke, Dominique Condo, Gregory R Cox, Shona L Halson, Alexander H K Montoye, Fiona Pelly, Jonathon Weakley, Gary Slater

{"title":"Influence of Guideline-Based Carbohydrate Intake on Training Adaptations, Health, and Sleep in Female Rugby Athletes: An Exploratory Study.","authors":"Rebekka Frazer, Christopher D Askew, Amy-Lee Bowler, Louise M Burke, Dominique Condo, Gregory R Cox, Shona L Halson, Alexander H K Montoye, Fiona Pelly, Jonathon Weakley, Gary Slater","doi":"10.1123/ijsnem.2026-0112","DOIUrl":"https://doi.org/10.1123/ijsnem.2026-0112","url":null,"abstract":"This exploratory study examined the effect of carbohydrate and subsequent energy availability (EA) on training adaptations, health, and sleep metrics across a 7-week preseason in semiprofessional female rugby union athletes. Full food provision on training days (four/week) manipulated carbohydrate intake: 6 versus 3 g·kg-1·day-1 for intervention (n = 7) and CON (n = 6), respectively while standardizing protein intake (>1.2 g·kg-1·day-1). Nontraining days involved ad libitum intake. Quantification of exercise energy expenditure via an individually calibrated wearable device allowed estimation of EA. Strength (three-repetition max squat, bench pull, and bench press), Bronco shuttle time; countermovement jump; biomarkers including iron studies, thyroid function, and cholesterol; sleep metrics; and physique (four-compartment model) were assessed before and after preseason. Training day carbohydrate intake was higher in intervention than CON (6.3 ± 0.2 vs. 3.1 ± 0.2 g·kg-1·day-1, p < .001), resulting in higher EA across the preseason (45.0 ± 5.8 vs. 29.9 ± 5.8 kcal·kg-1 fat-free mass-1·day-1, p < .001). Significant time effects were observed for bench pull (+3.6 kg, p = .024) and bench press (+4.6 kg, p = .011), fat mass (-1.1 kg, p < .001), fat-free mass (+1.2 kg, p = .025), and ferritin (-29 μg/L, p = .009). No significant interaction was observed for training adaptations, physique, or biochemical markers. Greater sleep duration was observed in CON on training nights, F(1, 156.072) = 5.821, p = .017, although other sleep metrics showed limited between-group differences. While increased carbohydrate intake improved EA, it had limited effect on training adaptations, health, or sleep metrics in this small, exploratory cohort.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-16"},"PeriodicalIF":2.5,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148897371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparing the Effects of Water, Sodium-Potassium, and Potassium-Rich Solutions on Fluid Balance and Thermal Strain Following Exercise in the Heat: A Randomized Triple-Blind Crossover Study. 比较水、钠钾和富钾溶液对高温运动后体液平衡和热应变的影响：一项随机三盲交叉研究

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-08-13 DOI: 10.1123/ijsnem.2026-0016

Joseph A Killick, Elliott J Jenkins, Jemima Benson, Jenna Macciochi, Liam Corr

{"title":"Comparing the Effects of Water, Sodium-Potassium, and Potassium-Rich Solutions on Fluid Balance and Thermal Strain Following Exercise in the Heat: A Randomized Triple-Blind Crossover Study.","authors":"Joseph A Killick, Elliott J Jenkins, Jemima Benson, Jenna Macciochi, Liam Corr","doi":"10.1123/ijsnem.2026-0016","DOIUrl":"https://doi.org/10.1123/ijsnem.2026-0016","url":null,"abstract":"Exercise in the heat perturbs human physiology through elevated core temperature, fluid loss, and cardiovascular strain. While fluid intake can mitigate these effects, the electrolyte composition of hydration solutions may improve rehydration efficacy. This study evaluated whether hydration strategy modulates thermal strain, inflammation, and performance during and after exercise in a hot environment, comparing three different fluid solutions: water, sodium-potassium drink, and coconut water. Twelve participants (seven males) completed a randomized, triple-blind crossover trial. Measures included handgrip strength, countermovement jump, tympanic temperature, thermal sensation, discomfort, body mass, body water percentage, heart rate, and total leukocyte count. Participants were randomly assigned 300 ml of one of three solutions before cycling for 60 min at 1.5 W/kg in ∼33 °C conditions. Additional 300-ml doses were consumed postexercise at 0, 30, and 60 min; measures were taken at each time point before solution consumption and at 90-min postexercise. Following exercise in the heat, a significant main effect for time was observed for all outcomes: thermal responses, heart rate, body mass and body water (p < .001); fatigue (p < .001); and leukocyte count (p = .016), indicating a strong physiological response to heat stress. However, no significant differences were observed between hydration strategies (p ≥ .152) for all measures. In conclusion, exercise in the heat elicited significant thermal strain, fatigue, and inflammation, independent of hydration strategy. Electrolyte composition did not significantly alter responses when fluid intake was controlled, highlighting the need for further research.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-9"},"PeriodicalIF":2.5,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148759246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Effect of a Repetitive Feeding Challenge With Carbohydrate Versus Fat on Markers of Gastrointestinal Integrity and Systemic Outcomes in Response to Endurance Exercise. 反复喂食碳水化合物和脂肪对耐力运动后胃肠道完整性和全身结局指标的影响

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-08-13 DOI: 10.1123/ijsnem.2026-0043

Isabel G Martinez, Jessica R Biesiekierski, Christopher E Rauch, Ricardo J S Costa

{"title":"The Effect of a Repetitive Feeding Challenge With Carbohydrate Versus Fat on Markers of Gastrointestinal Integrity and Systemic Outcomes in Response to Endurance Exercise.","authors":"Isabel G Martinez, Jessica R Biesiekierski, Christopher E Rauch, Ricardo J S Costa","doi":"10.1123/ijsnem.2026-0043","DOIUrl":"https://doi.org/10.1123/ijsnem.2026-0043","url":null,"abstract":"Athletes report consuming nutritionally dense foods before and during exercise to manage gastrointestinal symptoms (GIS). The study investigated whether fat, compared with carbohydrate (CHO), as a gut-training supplement, compromises gastrointestinal integrity and triggers systemic inflammation in response to endurance exercise. Thirty-six endurance athletes (seven females and 29 males) completed a preintervention gut-challenge trial (T1), involving a 2-hr run (60%V˙O2max) with CHO gel intake every 20 min (87 g/hr), followed by a 1-hr self-paced distance test. Participants were randomized to a fat (FFC; 20 g nut butter) or CHO supplement (CFC; 47 g CHO gel) for a feeding-challenge protocol (1 hr exercise with supplement for 7 days), followed by a gut-challenge retrial (T2). During T1 and T2, blood samples were collected before and after exercise to measure intestinal fatty-acid binding protein (I-FABP), soluble CD14 (sCD14), and C-reactive protein (CRP). Pre- to postexercise peak responses were similar within and between groups for plasma I-FABP (FFC: 254 ± 495 vs. 349 ± 622 pg/ml, p = .911; CFC: 344 ± 336 vs. 421 ± 362 pg/ml, p = .501; between groups T1: p = .404; T2: p = .440) and sCD14 (FFC: 0.346 ± 0.703 vs. 0.175 ± 0.603 μg/ml, p = .509; CFC: 0.336 ± 0.522 vs. 0.546 ± 0.777 μg/ml, p = .587; between groups T1: p = .888; T2: p = .149). CRP was significantly reduced in CFC (0.327 ± 0.449 vs. 0.062 ± 0.231 μg/ml, p = .030) but not in FFC (p = .351). Total-GIS severity during exercise or recovery were not correlated with I-FABP, sCD14, and CRP. The repetitive feeding-challenge with fat, compared with CHO, did not increase markers of gastrointestinal injury, bacterial endotoxin translocation, and systemic inflammation in response to endurance exercise.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-11"},"PeriodicalIF":2.5,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148758587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seven Days of Highbush Blueberry Supplementation Improves Trail Running Performance in Experienced Runners Without Elevating Physiological or Perceptual Stress Markers. 7天的高丛蓝莓补充可以改善有经验的跑步者的越野跑表现，而不会提高生理或感知压力标记。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-07-28 DOI: 10.1123/ijsnem.2026-0036

Luisa V Giles, Jason P Brandenburg

{"title":"Seven Days of Highbush Blueberry Supplementation Improves Trail Running Performance in Experienced Runners Without Elevating Physiological or Perceptual Stress Markers.","authors":"Luisa V Giles, Jason P Brandenburg","doi":"10.1123/ijsnem.2026-0036","DOIUrl":"https://doi.org/10.1123/ijsnem.2026-0036","url":null,"abstract":"Trail running, particularly with a downhill segment, can lead to muscle damage, oxidative stress, and inflammation-factors linked to fatigue. Antioxidant-rich foods like blueberries may help reduce these effects and improve performance. We evaluated 7 days of blueberry supplementation on physiological responses, performance, and recovery from a 22.2-km simulated trail race. Nine runners completed the race following 7 days of freeze-dried blueberry (BLU) and placebo (PLA) powder supplementation. Measurements taken prerace, immediately postrace, and 24 hr postrace included symptoms, pulse wave analysis, pulse wave velocity, reactive strength index, drop jump height, muscle soreness, pulmonary function, salivary cortisol, and immunoglobulin A. Fraction of exhaled nitric oxide was measured pre- and postrace. During the race, heart rate and ratings of perceived exertion for legs and lungs were assessed. Race time was significantly faster with BLU (p = .003), with no differences in race heart rate or ratings of perceived exertion. Supine heart rate (p = .031) and feelings of tiredness (p = .005) were lower in BLU, while FEV1/FVC was higher (p = .023). Drop jump height declined at 24 hr after the trail race in PLA (p = .022) but was preserved in BLU. Blueberry supplementation improved running performance without increasing physiological or perceptual stress.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-10"},"PeriodicalIF":2.5,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of 2 Days of Moderate or High Carbohydrate Intake on Physical and Cognitive Performance in Female Team Sport Players During a Simulated Soccer Match Protocol. 在模拟足球比赛方案中，2天中高碳水化合物摄入对女性团队运动运动员身体和认知表现的影响比较

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-07-28 DOI: 10.1123/ijsnem.2026-0098

Laura McManus, Michael Scriney, Brendan Egan

{"title":"Comparison of 2 Days of Moderate or High Carbohydrate Intake on Physical and Cognitive Performance in Female Team Sport Players During a Simulated Soccer Match Protocol.","authors":"Laura McManus, Michael Scriney, Brendan Egan","doi":"10.1123/ijsnem.2026-0098","DOIUrl":"https://doi.org/10.1123/ijsnem.2026-0098","url":null,"abstract":"High carbohydrate (CHO) intakes are recommended in the 24-48 hr before soccer matches to increase glycogen stores and delay the development of match-related fatigue, but this concept is unexplored in female soccer players. This study compared the effects of 2 days of divergent CHO intake on physical and cognitive performance during a simulated soccer match protocol. Using a double-blind, placebo-controlled, crossover design, 15 female field-based intermittent team sport players consumed either a high CHO diet (6 g·kg body mass [BM]-1·day-1; HIGH) or an isocaloric moderate CHO diet (3 g·kg BM-1·day-1; MOD) for 2 days after completing a standardized (∼35 min) intermittent exercise protocol. For the main experimental trials, participants completed the Loughborough Intermittent Shuttle Test as 5 × 15-min blocks of intermittent running followed by a shuttle run time to exhaustion, with cognitive performance assessed before and after the test. There was no significant difference (6.9 [-71.1, 84.8] s) in time to exhaustion between conditions (HIGH, 295 ± 137 s; MOD, 288 ± 133 s; p = .852; g = 0.05). Sprint times were faster during HIGH compared with MOD at Block 3 (p = .021; g = 0.33), Block 4 (p = .035; g = 0.31), and Block 5 (p < .001; g = 0.34). Rating of perceived exertion was lower during HIGH compared with MOD after Block 1 (p < .001; g = 0.78) and Block 2 (p = .018; g = 0.49). Reaction time in the Task Switching test was improved from pre- to postexercise in HIGH (p = .017; g = 0.67) but not MOD (p = .913; g = 0.05). These results suggest that female soccer players may benefit from increasing daily CHO intake to at least 6 g/kg BM for the 2 days preceding competitive matches.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-11"},"PeriodicalIF":2.5,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing Iron-Deficiency Screening for Female Athletes: Do We Need to Consider the Menstrual Cycle? 优化女性运动员缺铁筛查：我们需要考虑月经周期吗？

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-07-16 DOI: 10.1123/ijsnem.2025-0257

Alannah K A McKay, Rachel McCormick, Madison Pearson, Nicolin Tee, Rachel Harris, Clare Minahan, Peter Peeling, Kathryn E Ackerman, Louise M Burke

{"title":"Optimizing Iron-Deficiency Screening for Female Athletes: Do We Need to Consider the Menstrual Cycle?","authors":"Alannah K A McKay, Rachel McCormick, Madison Pearson, Nicolin Tee, Rachel Harris, Clare Minahan, Peter Peeling, Kathryn E Ackerman, Louise M Burke","doi":"10.1123/ijsnem.2025-0257","DOIUrl":"https://doi.org/10.1123/ijsnem.2025-0257","url":null,"abstract":"We examined factors that inform iron-deficiency screening practices in female athletes, with a focus on the menstrual cycle. Twenty-four National Rugby League athletes attended a 5-week training camp (age 21.6 ± 3.4 years old, body mass: 76.3 ± 12.1 kg, height: 164.9 ± 4.6 cm). Athletes were either naturally cycling (athleteNC; n = 11) or using hormonal contraception (athleteHC; n = 13). Venous blood samples were collected during Phases 1, 2, and 4 of the menstrual cycle in athleteNC for determination of iron status. Three equally spaced, corresponding time points were sampled in athleteHC. Every 48 hr, a capillary blood sample was collected and analyzed for ferritin, hepcidin, creatine kinase, and C-reactive protein. No differences across menstrual phases or groups were evident for ferritin, hepcidin, transferrin or hemoglobin (p > .05). Serum iron (12.9 ± 4.6 μmol/L to 16.9 ± 8.5 μmol/L; p = .045) and transferrin saturation (17.3% ± 7.8% to 22.1% ± 14.5%; p = .041) increased from Phase 1 to Phase 2 in athleteNC only, with no change seen in athleteHC. Ferritin (-16%; p < .001) and hepcidin (-23%; p < .001) declined across the training camp in all athletes. Concentrations of C-reactive protein (p = .039) were consistently higher in athleteHC compared with athleteNC, whereas creatine kinase activity were similar between groups (p = .140). Our findings did not identify clear menstrual cycle phase-related differences in markers of iron status or regulation, suggesting that the influence of cycle phase may be relatively small compared with other sources of variation. Practitioners should be mindful that athletes using hormonal contraceptives may report with greater C-reactive protein concentrations than naturally cycling athletes.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-10"},"PeriodicalIF":2.5,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nutrition for Elite Male Ice Hockey: Evidence-Based Recommendations. 优秀男子冰球运动员的营养：循证建议。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-06-26 DOI: 10.1123/ijsnem.2025-0260

Anine Nordstrøm

{"title":"Nutrition for Elite Male Ice Hockey: Evidence-Based Recommendations.","authors":"Anine Nordstrøm","doi":"10.1123/ijsnem.2025-0260","DOIUrl":"https://doi.org/10.1123/ijsnem.2025-0260","url":null,"abstract":"Ice hockey is a high-intensity intermittent team sport where games of 3 × 20-min periods involve on-ice shifts (typically lasting ∼30-80 s) interspersed with passive recovery periods (2-5 min). Playing requires endurance, speed, strength, and balance in conjunction with technical, tactical, and cognitive abilities. Nutrition can play a valuable role in optimizing physical and mental performance and in maintaining overall health of ice hockey players. The aim of this review is to provide evidence-based nutrition guidelines for elite male ice hockey players. The energy demands during training sessions and games in ice hockey are not well investigated, but elite players typically cover 2.3-6.7 km in their 15-25 min of on-ice time during games. Carbohydrate (primarily muscle glycogen) is the major fuel during training and match play, and match performance has been shown to be associated with the pregame muscle glycogen content. Sweat losses are typically high (2.02 ± 0.74 L/hr) due to the high intensity and the use of protective equipment. Sufficient carbohydrate and fluid intake are therefore the most important nutritional considerations during training sessions, games, and recovery to maintain performance. Protein intake is important after training sessions and games to support muscle repair, growth, and overall recovery. Nutrition plans should be personalized and periodized to meet the demands of training sessions and games, and individual objectives. Players should prioritize food before supplements to meet nutrient requirements. While studies on supplementation are scarce, supplements that might be beneficial to some ice hockey players include Vitamin D, iron, caffeine, and creatine.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-13"},"PeriodicalIF":2.5,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148338568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beyond Belief? Absence of Double-Blinding and Limited Ecological Validity in Carbohydrate Loading Research. 难以置信?碳水化合物负荷研究缺乏双盲和有限的生态效度。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-06-24 Print Date: 2026-09-01 DOI: 10.1123/ijsnem.2026-0058

Robyn O Jones, Julien Louis, Bryan Saunders, James P Morton, Kasper Gejl, Joachim Nielsen, José L Areta

{"title":"Beyond Belief? Absence of Double-Blinding and Limited Ecological Validity in Carbohydrate Loading Research.","authors":"Robyn O Jones, Julien Louis, Bryan Saunders, James P Morton, Kasper Gejl, Joachim Nielsen, José L Areta","doi":"10.1123/ijsnem.2026-0058","DOIUrl":"10.1123/ijsnem.2026-0058","url":null,"abstract":"Carbohydrate loading (CL) has long been a cornerstone of endurance nutrition, yet its true efficacy remains uncertain. Although CL is commonly associated with improved time to fatigue and modest performance gains in exercise lasting ∼90-240 min, few studies have employed double-blind, placebo-controlled (DBPC) designs. Given that belief and expectation can independently influence performance, it remains unclear whether reported benefits reflect CL or placebo effects. We systematically evaluated the use of blinding and in-exercise carbohydrate provision in CL research. Of 14 identified studies, only two were DBPC trials. Notably, only four provided carbohydrates during exercise. Both DBPC studies included appropriate in-exercise carbohydrate intake and reported no evidence of performance benefit of CL. Of the remaining two studies that provided carbohydrates during exercise, CL showed a positive performance effect; however, the effect size was moderate and comparable to that reported for placebo nutritional interventions (Cohen's d ≈ 0.35). Comparisons across CL studies are heterogeneous in design, including differences in performance test type (time to exhaustion vs. time trial), which points to the need for more research in standardized conditions. The current evidence therefore calls for a re-evaluation of whether CL in the 24-48 hr before competition enhances performance once placebo effects are accounted for and in-race fueling is optimized. This commentary highlights the need for more DBPC studies and the potential role of placebo (such as belief) in observed performance outcomes. We propose future research directions to better isolate the independent contributions of CL and placebo effects in endurance performance.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"553-562"},"PeriodicalIF":2.5,"publicationDate":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148317111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Addressing the Evidence Gap: Ergogenic Effects of Caffeine on Cycling Performance in Females-A Systematic Review and Three-Level Meta-Analysis. 解决证据差距：咖啡因对女性自行车运动表现的影响——一个系统评价和三水平荟萃分析。

IF 2.5 3区医学

International journal of sport nutrition and exercise metabolism Pub Date : 2026-05-28 Print Date: 2026-09-01 DOI: 10.1123/ijsnem.2026-0022

Gloria Bittencourt de Santa Ritta, Luiza Mariana Brito Soares, Ana Clara Pereira Abreu, Guilherme Falcão Mendes, Bryan Saunders, Caio Eduardo Gonçalves Reis

{"title":"Addressing the Evidence Gap: Ergogenic Effects of Caffeine on Cycling Performance in Females-A Systematic Review and Three-Level Meta-Analysis.","authors":"Gloria Bittencourt de Santa Ritta, Luiza Mariana Brito Soares, Ana Clara Pereira Abreu, Guilherme Falcão Mendes, Bryan Saunders, Caio Eduardo Gonçalves Reis","doi":"10.1123/ijsnem.2026-0022","DOIUrl":"10.1123/ijsnem.2026-0022","url":null,"abstract":"This systematic review and meta-analysis aimed to determine the effect of caffeine ingestion on female cycling performance. Three databases were systematically searched; studies were screened according to PICOS framework and PRISMA guidelines. Data were analyzed using a three-level meta-analytical model to account for the nesting of multiple performance outcomes within individual studies. Subgroup analyses assessed the influence of caffeine dose, training level, and menstrual cycle phase. Risk of bias was assessed using the RoB 2 tool; heterogeneity was assessed using the Q test and funnel plot analysis. Nineteen randomized crossover trials involving 235 females were included. The pooled analysis revealed a small and significant ergogenic effect of caffeine supplementation on cycling performance for females (standardized mean difference = 0.21; 95% confidence interval [0.11, 0.29]), with high certainty of evidence. Subgroup analysis showed a nonsignificant effect for caffeine dose (p = .79) and training level (p = .97), while caffeine significantly improved performance during the mid-luteal phase (standardized mean difference = 0.26; 95% confidence interval [0.06, 0.46]; p = .01) with no effect for other menstrual cycle phases (p > .11). Heterogeneity was nonsignificant, Q(36) = 7.99; p = 1.00, and overall risk of bias was rated as \"some concerns.\" The limited clinical trials and inadequate menstrual cycle assessments preclude definitive conclusions regarding the effect of the menstrual cycle phases. These findings support the supplementation of caffeine to optimize performance in cycling for women.","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"574-587"},"PeriodicalIF":2.5,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148054565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0