International journal of sport nutrition and exercise metabolism最新文献

{"title":"The Acute Effects of Caffeine and Normobaric Hypoxia on Cardiorespiratory Exercise Responses in Healthy Adults: A Randomized Controlled Trial.","authors":"Benjamin Jonathan Narang, Ana Štritof, Tadej Debevec","doi":"10.1123/ijsnem.2025-0024","DOIUrl":"https://doi.org/10.1123/ijsnem.2025-0024","url":null,"abstract":"<p><p>The ergogenic effects of caffeine for endurance performance at sea level are well established. However, whether caffeine enhances exercise capacity or modulates cardiorespiratory responses in hypoxia remains unclear. Twenty-nine healthy, active volunteers (14 women) completed four tests in a pseudorandomized order, comprising 10 min of steady-state cycling (40% normoxic maximal aerobic power) followed by incremental exercise tests to exhaustion. Participants consumed 6 mg/kg body mass anhydrous caffeine, or placebo, 45 min before exercise. Tests were performed while breathing room air or a hypoxic gas mixture (simulating ∼3,500 m). At peak exercise intensity, oxygen uptake was affected by condition (hypoxia vs. normoxia; 44.8 ± 7.3 vs. 51.4 ± 7.9 ml·kg-1·min-1; p < .001) but not supplement (caffeine vs. placebo; 48.2 ± 8.2 vs. 48.0 ± 8.4 ml·kg-1·min-1; p = .501). Maximal aerobic power and pulse oxygen saturation were lower in hypoxia (both p < .001), but unaffected by caffeine (p = .061 and .898, respectively). Pulmonary ventilation was unaffected by hypoxia (p = .154) or caffeine (p = .117). Heart rate was higher in normoxia and with caffeine (both p < .001). During steady-state cycling, hypoxia (p < .001) and caffeine (p = .026) increased pulmonary ventilation. However, the hypoxia-induced pulse oxygen saturation decrease (p < .001) was not attenuated with caffeine (interaction p = .283). Perceived exertion was higher in hypoxia (p < .001) and lower with caffeine (p = .026). Caffeine increased vastus lateralis oxygenation in hypoxia (caffeine vs. placebo; 52 ± 8 vs. 50 ± 10%; p = .020) but not in normoxia (caffeine vs. placebo; 59 ± 7 vs. 59 ± 8%; p > .999). Overall, caffeine did not enhance exercise capacity in either environmental condition. However, during steady-state cycling, caffeine enhanced pulmonary ventilation, reduced perceived exertion, and mitigated hypoxia-induced muscle oxygenation reductions.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-9"},"PeriodicalIF":3.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144659170","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}

{"title":"Could It Bee? Honey Ingestion Induces Comparable Metabolic Responses to Traditional Carbohydrate-Based Sports Nutrition Product During 3-Hr Steady-State Cycling and Subsequent Exercise Capacity Test.","authors":"Harvey O Fortis, Samanvita Ravikanti, Jennifer S Barrett, Erick M Lopez, Theodoros M Bampouras, Jordan J Haworth, José L Areta, Jamie N Pugh","doi":"10.1123/ijsnem.2024-0244","DOIUrl":"10.1123/ijsnem.2024-0244","url":null,"abstract":"<p><p>The present study investigated the effects of honey compared with a traditional carbohydrate based sports nutrition product (TRAD-CHO) on metabolic and gastrointestinal responses during exercise, as well as exercise capacity. In a randomized crossover design 12 trained males ingested 90 g × hr-1 of carbohydrate in the form of TRAD-CHO, or honey (HONEY) during 180 min of steady-state cycling undertaken at 90% lactate threshold, followed by a capacity test consisting of a time to fatigue at 120% of lactate threshold. Mean total CHO oxidation (HONEY 2.47 ± 0.37 g × min-1, TRAD-CHO 2.41 ± 0.39 g × min-1) and fat oxidation (HONEY 0.44 ± 0.12 g/min, TRAD-CHO 0.42 ± 0.10 g/min) were not different between trials during steady-state cycling (p = .517). The overall incidence of gastrointestinal symptoms rated as \"moderately severe\" or worse was low. There was no difference in time to fatigue (p = .517). There was no difference in breath hydrogen postexercise (p = .319) and the number of participants in each condition, with >20 parts per million rise from baseline not significantly different between conditions (6: SPORT, 7 HONEY: p = 1.00). From these data, honey could be a potentially alternative fueling option to commercial TRAD-CHO, with the current data providing no evidence of any systematic differences between the conditions on whole-body carbohydrate oxidation and endurance capacity test.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-9"},"PeriodicalIF":3.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144659169","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}

{"title":"Negligible Effects of Fructose-Glucose Composite Carbohydrates on Performance Across a Prolonged Soccer Match Simulation Compared With a Glucose-Only Control in Semiprofessional Soccer Players.","authors":"Anne Fischer, Liam Corr, Laurence P Birdsey, Mark Hearris, Paul Morgan, Nathan Hodson, Diogo Martinho, James Fleming, Magni Mohr, Peter Krustrup, Mark Russell, Craig Sale, Liam David Harper, Adam Field","doi":"10.1123/ijsnem.2024-0253","DOIUrl":"10.1123/ijsnem.2024-0253","url":null,"abstract":"<p><p>Higher carbohydrate availability, achieved through combined intake of glucose and fructose, has been shown to enhance endurance performance. This study examined the effects of higher carbohydrate doses containing a fructose-glucose mixture (1:2 ratio) compared with lower doses containing only glucose on performance during a 120-min simulated soccer match. Fifteen semiprofessional soccer players (seven males and eight females) completed two 120-min soccer-specific exercise sessions in a randomized and crossover design. Participants consumed either 60 g/hr glucose or a combination of 0.5 g/min fructose and 1.0 g/min glucose (90 g/hr) at preexercise, halftime, full time, and midway through extra time. Measures, including gastrointestinal discomfort, mental fatigue, passing accuracy, neuromuscular performance (reactive strength index, countermovement jump height, and peak power output), and sprint performance (15- and 30-m sprints), were assessed at 0, 45, 90, and 120 min. Blood glucose and lactate concentrations were assessed every 15 min. Fructose-glucose coingestion elevated blood glucose concentration from 105 min (p = .006, d = 1.2) but did not maintain performance (p > .05). Gastrointestinal symptoms of gastric reflux at 45 min (p = .011, d = 0.9), fullness at 90 min (p = .013, d = 0.9), and flatulence at 120 min worsened in the glucose group (p = .003, d = 1.1). Abdominal cramps were greater in the fructose-glucose group at 45 (p < .001, d = 1.7) and 90 min (p < .001, d = 1.6). Although supplementation did not influence any other variables (p > .05), countermovement jump height, peak power output, and sprint performance were negatively influenced by exercise in both conditions (p < .05). A higher carbohydrate dosage of fructose-glucose coingestion increases blood glucose concentrations but does not mitigate technical and neuromuscular performance impairments during a prolonged simulated soccer match.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-12"},"PeriodicalIF":3.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333115","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}

{"title":"No Effect of Topical Application of a Commercial Magnesium Gel on Exercise Recovery in Active Individuals.","authors":"Alexandra M Coates, Dhriti V Patel, Emileigh R Binet, Martin J Gibala","doi":"10.1123/ijsnem.2025-0034","DOIUrl":"10.1123/ijsnem.2025-0034","url":null,"abstract":"<p><p>Oral magnesium supplementation can reduce muscle soreness and muscle damage markers after unaccustomed exercise. However, the effectiveness of topical magnesium applications remains unclear. This randomized, double-blind, parallel-design study investigated whether a commercial magnesium gel could reduce the perception of muscle soreness and muscle damage markers following an acute bout of unaccustomed exercise. Healthy active participants (n = 35) performed a 40-min bout of downhill treadmill running. Magnesium (Mg) or placebo (Pla) gels were administered to each thigh 10 min before and immediately after exercise. Measurements were made before (Pre) and immediately (Post), 24 hr, and 48 hr after exercise. The primary outcome was muscle soreness using a 0-100 visual analog scale after a sit-to-stand maneuver. Secondary outcomes included peak isometric knee extensor strength, plasma creatine kinase, and serum interleukin-6. There were no differences between treatments on any outcome. Compared with Pre (Mg: 4 ± 5, Pla: 4 ± 5 a.u.), muscle soreness was higher post (Mg: 28 ± 20, Pla: 21 ± 14) and after 24 hr (Mg: 43 ± 27, Pla: 41 ± 26) and 48 hr (Mg: 42 ± 31, Pla: 32 ± 23) (all main effects, p < .0001). Interleukin-6 was higher Post (Mg: 1.8 ± 0.7, Pla: 1.6 ± 0.7 pg/ml) versus Pre (Mg: 1.1 ± 0.8, Pla: 1.1 ± 0.6; main effect, p = .006), and creatine kinase was higher Post (Mg: 111 ± 57, Pla: 121 ± 44 U/L), 24 hr (Mg: 216 ± 113, Pla: 228 ± 97), and 48 hr (Mg: 136 ± 45, Pla: 179 ± 85) versus Pre (Mg: 93 ± 54, Pla: 91 ± 30; all main effects, p < .001). Knee extensor strength was reduced after exercise (main effect, p = .04). The Mg gel did not reduce muscle soreness or muscle damage markers after unaccustomed exercise compared with Pla. The dose (0.53 mg/ml) or application protocol may have been insufficient to elicit a meaningful effect.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-8"},"PeriodicalIF":3.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333116","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}

{"title":"Comparison of Ramp and Step Graded Cardiopulmonary Exercise Tests for the Estimate of Substrate Oxidation Rates in Recreationally Active Individuals.","authors":"Lorenzo Nesti, Lorenza Santoni, Silvia Frascerra, Martina Chiriacò, Andrea Natali","doi":"10.1123/ijsnem.2024-0236","DOIUrl":"https://doi.org/10.1123/ijsnem.2024-0236","url":null,"abstract":"<p><p>Fat oxidation rates are key determinants of exercise capacity and metabolic health, evaluated by indirect calorimetry during step graded exercise test. We sought to verify whether indirect calorimetry applied to ramp graded exercise test provides comparable results to the reference test and to identify the physiological bases of possible dissimilarities. To this aim, 14 healthy volunteers performed two cardiopulmonary exercise tests with concomitant stress echocardiography according to standard protocols until limit of tolerance on separate days, in randomized order. Compared at matched exercise intensities, expressed as percentage of estimated maximal rate of oxygen uptake (%V˙O2max), indirect calorimetry applied to ramp provided identical kinetics of macronutrient oxidation, with a negligible (7%, p > .05) constant overestimation of fat and underestimation of carbohydrate oxidation rates. Despite identical hemodynamic and ventilatory parameters throughout the tests, we observed a minute downward shift of the Δ V˙CO2/Δ V˙O2 intercept with ramp in comparison to step (-0.05 ± 0.09 L/min; p = .077) due to delayed alignment of gas exchange to work rate, which explains the differences in substrate oxidation values between the two tests. Ramp macronutrient oxidation rates were fully normalized by correcting the stoichiometric equations for the Δ V˙CO2/Δ V˙O2 intercept difference. In conclusion, cardiopulmonary and metabolic responses are dependent on exercise intensity and not on the protocol used. Indirect calorimetry applied to ramp protocols correctly identifies the kinetics of macronutrient oxidation while introducing minimal differences in the absolute values due to different gas-exchange response that can be mathematically corrected by applying the Δ V˙CO2/Δ V˙O2 correction factor.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-10"},"PeriodicalIF":3.0,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144186979","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}

{"title":"Effects of Carotenoid Supplementation on Exercise-Induced Oxidative Stress: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.","authors":"Xing Ye, Yanchun Li","doi":"10.1123/ijsnem.2024-0256","DOIUrl":"https://doi.org/10.1123/ijsnem.2024-0256","url":null,"abstract":"<p><strong>Objective: </strong>This study aims to investigate the potential effects of carotenoid supplementation on mitigating exercise-induced oxidative stress and to provide guidance for future research.</p><p><strong>Methods: </strong>We conducted a systematic review and meta-analysis using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched multiple databases from inception to August 2024 for randomized clinical trials investigating the effects of carotenoid supplementation on biomarkers of oxidative stress, inflammatory markers, antioxidant levels, and metabolic parameters in the context of exercise-induced oxidative stress. The search terms included \"carotenoids,\" \"supplementation,\" \"exercise,\" \"oxidative stress,\" \"inflammation,\" \"antioxidants,\" \"metabolic parameters,\" and their synonyms. Two reviewers independently extracted study data, with disagreements resolved by a third reviewer. Quality was assessed by the Cochrane risk-of-bias method. Random and fixed effects models were used for the analysis of standard mean differences (SMD) or weighted mean differences (MDs) with 95% confidence intervals (CI).</p><p><strong>Results: </strong>A total of 12 studies were included in the final analysis. Carotenoid supplementation led to significant effects in assessing oxidative stress induced by exercise (overall oxidative stress: SMD = -0.55, 95% CI [-1.04, -0.06]; malondialdehyde: MD = -0.05, 95% CI [-0.09,-0.02]; total antioxidant capacity: MD = 0.03, 95% CI [0.02, 0.03]; 8-isoprostane: MD = -35.70, 95% CI [-59.32, -12.09]; lipid peroxide: SMD = -1.07, 95% CI [-1.94, -0.20]; and nitric oxide: MD = -8.07, 95% CI [-12.54,-3.59]), inflammatory markers (inflammatory levels: SMD = 1.63, 95% CI [0.81, 2.46]; interleukin levels: SMD = 1.54, 95% CI [0.69, 2.40]; and C-reactive protein: MD = 4.56, 95% CI [0.97, 8.14]), antioxidant levels (SMD = 0.84, 95% CI [0.14, 1.53]), and metabolic parameters (energy expenditure: SMD = -0.52, 95% CI [-0.78, -0.26]; p < .05).</p><p><strong>Conclusion: </strong>Carotenoid supplementation appears to attenuate exercise-induced oxidative stress and the inflammatory response and improve antioxidant levels and metabolic capabilities. However, these results may be influenced by participant variability or methodological differences. Further research with larger sample sizes, longer supplementation periods, higher doses, and carotenoid bioavailability is needed to confirm these findings.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-18"},"PeriodicalIF":3.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127635","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}

{"title":"Caffeine Augments Sustained Hyperemia in Previously Exercised Leg in Male Competitive Long-Distance Runners.","authors":"Naoto Fujii, Taiga Hirayama, Ryoko Matsutake, Shota Ohki, Yoshiharu Nabekura, Tsutomu Hiroyama, Takeshi Nishiyasu","doi":"10.1123/ijsnem.2024-0191","DOIUrl":"10.1123/ijsnem.2024-0191","url":null,"abstract":"<p><p>Blood flow in exercised skeletal muscle remains elevated postexercise, potentially playing a critical role in recovery and adaptation process. However, effective and easily implementable interventions that augment this response have yet to be identified. In this study, we investigated whether caffeine intake enhances sustained postexercise hyperemia in previously active leg in competitive long-distance runners. Ten competitive male long-distance runners participated in baseline measurements, during which cardiorespiratory responses, including leg blood flow measured by ultrasound Doppler equipment, were assessed in a supine position. Subsequently, they ingested either (a) placebo capsules or (b) capsules containing 6 mg/kg caffeine in a randomized, counterbalanced, double-blind, and crossover manner. They then completed 8-min high-intensity treadmill running at 98% of the average running speed of their estimated 10,000-m best time, followed by postexercise measurements assessing the same cardiorespiratory responses. Postexercise leg blood flow was elevated from baseline, and this response was 17% higher in caffeine relative to placebo condition (between-trial difference in average with [95% CI] = 182 [2.33, 363] ml/min, p = .048, d = 1.03). Caffeine ingestion also increased minute ventilation (2.06 [0.603, 3.53] L/min, p = .011, d = 1.17), whereas it reduced end-tidal CO2 partial pressure (-2.09 [-3.68, -0.504] mmHg, p = .015, d = 1.15) postexercise relative to placebo condition. We show that preexercise 6 mg/kg caffeine intake increases postexercise leg blood flow following high-intensity running in male competitive long-distance runners. Our results stimulate future studies to assess if caffeine-induced elevations in leg blood flow accelerates recovery and/or adaptations.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"312-323"},"PeriodicalIF":3.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143983774","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}

{"title":"Female Athletes Report Positive Experiences as Research Participants.","authors":"Ella S Smith, Alannah K A McKay, Kathryn E Ackerman, Kirsty J Elliott-Sale, Trent Stellingwerff, Rachel Harris, Louise M Burke","doi":"10.1123/ijsnem.2024-0182","DOIUrl":"https://doi.org/10.1123/ijsnem.2024-0182","url":null,"abstract":"<p><p>Given the underrepresentation of women in sports and exercise science research, we sought to understand the experiences of female athletes currently involved in applied sports and exercise science research to inform future studies and potentially increase participation rates. Accordingly, we investigated the experiences of 89 female athletes (n = 48 cyclists/triathletes, n = 19 race walkers, n = 22 National Rugby League Indigenous Women's Academy players) who participated in four separate studies of sports performance with different methodological characteristics. Participants completed a questionnaire upon study completion that queried prior research participation, reasons for participating and experiences during the current study. Across all 89 athletes, 81% were first-time research participants, with the primary barriers cited as a perceived lack of opportunities or being unaware of opportunities (93%). Participants rated an interest in the research outcome as the most important aspect influencing their decision to participate (90 ± 14 [out of 100]), followed by the opportunities to receive personalized results (84 ± 20) and education (78 ± 27). Most participants (87%) stated that they would apply the study findings to their sports involvement, while the remaining 13% reported that they required support to understand the application of results. The majority (94%) of participants indicated a willingness to participate in future studies, while the research experience was rated positively at a mean 77 out of 100. Ultimately, our findings uncovered a perceived lack of opportunity as the primary barrier to female athlete research participation. As such, opportunities for women to participate in high-quality studies should be prioritized.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"1-11"},"PeriodicalIF":3.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017752","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}

{"title":"Impact of Overnight Fasted State Versus Fed State on Adaptations to Resistance Training: A Randomized Clinical Trial.","authors":"Alexandra Ferreira Vieira, Eduarda Blanco-Rambo, Marcelo Bandeira-Guimarães, Ramiro Teixeira Silva, Andressa Fergutz, Isabel de Almeida Paz, Samuel Vargas Munhoz, Renato Colombelli, Marco Aurélio Vaz, Rodrigo Cauduro Oliveira Macedo, Eduardo Lusa Cadore","doi":"10.1123/ijsnem.2024-0215","DOIUrl":"10.1123/ijsnem.2024-0215","url":null,"abstract":"<p><p>The aim was to verify the effects of 12 weeks of resistance training (RT) performed in the fasted state compared with the fed state on body composition and physical performance in young adults. Participants were randomly assigned into fasting RT group (Fast-RT, n = 15) and fed RT group (Fed-RT, n = 13). Both groups trained two weekly resistance exercise sessions after an overnight fast or between 1 and 2 hr after consumption of a carbohydrate-rich meal, associated with isocaloric nutritional guidance. Assessments of body composition (dual-energy X-ray absorption), quadriceps muscle thickness (ultrasonography), maximum dynamic strength (one repetition maximum test), and muscle power in bench press and knee-extension exercises were performed before and after 12 weeks of intervention. Both Fast-RT and Fed-RT groups showed increases (p time ≤ .01) in quadriceps muscle thickness (1.21 and 1.18 cm, respectively; p group = .371; p Group × Time = .871), maximum dynamic strength (bench press: 10.53 and 4.89 kg, respectively; p group = .251; p Group × Time = .268; knee extension: 28.53 and 29.31 kg, respectively; p group = .919; p Group × Time = .846), and muscle power (knee extension mean power 70% one repetition maximum: 59.28 and 46.21 W, respectively; p group = .833; p Group × Time = .616; knee extension maximal power 70% one repetition maximum: 100.65 and 54.76 W, respectively; p group = .812; p Group × Time = .409). Regardless of food consumption prior to the sessions (fasted state and fed state), RT performed twice weekly across 12 weeks was associated with improvements in muscle hypertrophy and neuromuscular performance in young adults.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"291-302"},"PeriodicalIF":3.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017754","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}

{"title":"Is It Required to Abstain From Fluid Consumption in the 10 Min Before Collection of a Saliva Sample?","authors":"Diogo V Leal, John Hough","doi":"10.1123/ijsnem.2024-0192","DOIUrl":"10.1123/ijsnem.2024-0192","url":null,"abstract":"<p><p>The noninvasive and reliable saliva collection method for stress-related endocrine biomarkers analysis has become common in field- and laboratory-based research in the last 15 years. Current guidelines recommend interrupting water consumption 10 min before saliva sampling to avoid inaccurate, diluted concentrations of the biomarkers being examined. However, the impact of saliva dilution on salivary cortisol and testosterone levels has not been examined yet. This was a randomized, crossover experiment. Fourteen active healthy males completed three separate cycle-bout trials, where a set volume of water (250 ml) was consumed 10, 5, or 1 min before saliva sampling. Saliva was collected pre-, post-, and 30 min postexercise. No differences were observed in resting samples in any of the trials (p < .05). However, salivary cortisol increased from pre- to postexercise in the 10 (+52%, p = 0.022) and 5-min trial (+36%, p = .005) only. Salivary testosterone also increased in 10 (+34%, p = .005), 5 (+37%, p < .001), and 1-min trials (+24%, p < .035). This study proposes that consuming water up to 1 min before providing a saliva sample will not dilute the sample, allowing for an accurate determination of salivary cortisol and testosterone concentration levels. Practically, the 10-min fluid abstinence required before saliva sampling in the previous guidelines could be reduced to 1 min; however, if examining the response of salivary cortisol to an exercise trail, a fluid abstinence of 5 min may be more appropriate. This conclusion will allow for less restriction on researchers and participants alike.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":" ","pages":"355-362"},"PeriodicalIF":3.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143788113","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}