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Musculoskeletal injuries are prevalent in professional soccer and can result in lost training time or match play. It is intuitive that the "return to play" (RTP) pathway will depend, in large part, on the expertise of sports medicine practitioners (e.g. surgeons, physicians, physiotherapists) responsible for player's recovery. Consensus statements on returning athletes to sport following injury acknowledge the contributions of sport psychology and sports nutrition. However, specific consideration on how to integrate these two recognized – but often overlooked components of injury rehabilitation – into existing sport medicine approaches has yet to be examined. Using a framework of milestones directed by the medical physician and physical trainer, the evidence is summarized and suggestions provided on the integration of sports psychology and sports nutrition into an interdisciplinary RTP approach. We examine recovery from a phase approach (acute injury and functional recovery) to highlight interdisciplinary opportunities in the management of musculoskeletal soccer injuries. An interdisciplinary approach is understood to achieve outcomes that could not be achieved within the framework of a single discipline. The incorporation of sports psychology and nutrition theoretically compliment milestones used in current medically-based RTP models. Our hope is that this article serves as a catalyst for interdisciplinary practice and research – not only in sports nutrition and sports psychology – but across all sport and exercise disciplines. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the influence of mouth rinsing a CHO-electrolyte (CHO-E) solution on 1-h running performance. A second study determined whether mouth rinsing a CHO-E solution altered the blood glucose and plasma insulin concentrations at rest. Methods: After a 13-h fast, 10 endurance-trained male runners completed two 1-h performance runs on an automated treadmill while mouth rinsing 25 mL of either a 6.4% CHO-E (C) or placebo (P) solution immediately before and at 15-min intervals during the 1-h run. An additional 10 healthy active males followed the same mouth rinsing procedure during a 1-h resting period. Finger prick blood samples were obtained for the determination of blood glucose and plasma insulin concentrations. Results: Runners covered 211 m (90% confidence intervals = 42-380 m, P = 0.048) further during the C trial (14,298 ± 685 m, mean ± SD) in comparison with the P trial (14,086 ± 732 m). There was no change in blood glucose concentrations during the 1-h run (P: pre = 4.3 ± 0.2 mmol·L-1, post = 4.3 ± 0.3 mmol·L-1; C: pre = 4.3 ± 0.4 mmol·L-1, post = 4.3 ± 0.3 mmol·L-1). At rest, there was no change in blood glucose (P: 4.3 ± 0.1 mmol·L-1, C: 4.3 ± 0.2 mmol·L-1) or plasma insulin (P: 6.2 ± 1.1 mU·L-1, CHO: 5.9 ± 1.0 1.1 mU·L-1) concentrations (P > 0.10). Conclusions: Mouth rinsing a 6.4% CHO-E solution was associated with increased distance covered during a 1-h performance run in comparison to mouth rinsing a placebo solution. Mouth rinsing a CHO-E was not associated with changes in blood glucose concentration during exercise or at rest. [ABSTRACT FROM AUTHOR]

The gut microbiome plays a significant role in physiological functions such as nutrient processing, vitamin production, inflammatory response, and immune modulation, which, in turn, are important contributors to athlete health and performance. To date, the interpretation, discussion, and visualization of microbiome results of athletes are challenging, due to a lack of standard parameters and reference data for collection and comparison. The purpose of this perspective piece is to provide researchers with an easy-to-understand framework for the collection, analysis, and data management related to the gut microbiome with a specific focus on athletic populations. In the absence of a consensus on microbiome research in the sports field, we hope that these considerations serve as foundational "best practice." Adherence to these standard operating procedures will accelerate the path toward improving the quality of data and ultimately our understanding of the influence of the gut microbiome in sport settings., Competing Interests: Declaration of interests R.I. is an employee of the Gatorade Sports Science Institute, a division of PepsiCo, Incorporated. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Incorporated., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Carbohydrate (CHO) and caffeine (CAF) mouth rinsing have been independently reported to benefit sport performance. The proposed mechanisms by which mouth rinsing CHO exerts an influence are reported to be different from those for mouth rinsing CAF. However, the potential ergogenic effects of combining CHO and CAF in a single mouth rinse solution, are unclear. This study aimed to review the available evidence of CHO-CAF combined mouth rinse on exercise and cognitive performance in human participants. A systematic literature search was conducted using five databases until April 2024, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) recommendations. Among the nine randomized crossover studies included, only one study showed significant improvements in lower-body muscular endurance with CHO-CAF mouth rinse (effect size (ES): 0.48; p  < 0.05), while two studies reported non-statistically significant improvements in repeated sprint performance compared to other mouth rinse and placebo conditions (ES: 0.20-0.81; p  = 0.07-0.18). However, for other performance measures, including repeated jumps, upper-body strength and endurance, endurance cycling, and intermittent recovery run, most evidence (five studies) did not demonstrate significant ergogenic effects. Notably, of the two studies that examined cognitive performance, both reported significant improvements with CHO-CAF mouth rinse compared with the placebo condition (ES: 0.45-3.45; p  < 0.05). Overall, a synergistic influence of CHO-CAF mouth rinse on physical exercise performance is not evident, but preliminary evidence suggests potential benefits on cognitive performance. Future studies are required to address various methodological issues identified in this review, while practitioners and athletes should exercise caution when considering this novel nutritional strategy., Competing Interests: IR is an employee of the Gatorade Sports Science Institute, a division of PepsiCo, Inc. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Inc.

Objectives: Dietary strategies to improve arachidonic acid:eicosapentaenoic acid (AA:EPA) ratios are of interest due to potential reductions in inflammation and oxidative stress following exercise. The aim of this study was to investigate the impact of a novel dietary intervention, that is, the ingestion of 30 g of dark chocolate, on blood lipid profiles and gut microbiota composition in elite male soccer players., Methods: Professional male soccer players were randomly assigned to the experimental group (DC) provided with 30 g of dark chocolate or to the control group (WC), provided with 30 g of white chocolate, for 30 days. Before and after intervention, blood, fecal sample, and anthropometry data were collected. For each outcome, two-way repeated-measure analysis of variance was used to identify differences between baseline and endpoint (Week 4), considering treatment (dark chocolate, white chocolate) as intersubjects' factors. Metagenomic analysis was performed following the general guidelines, which relies on the bioBakery computational environment., Results: DC group showed increased plasma polyphenols (from 154.7 ± 18.6 μg gallic acid equivalents/ml to 185.11 ± 57.6 μg gallic acid equivalents/ml, Δ pre vs. post = +30.41 ± 21.50) and significant improvements in lipid profiles: total cholesterol (Δ -32.47 ± 17.18 mg/dl DC vs. Δ -2.84 ± 6.25 mg/dl WC, Time × Treatment interaction p < .001), triglycerides (Δ -6.32 ± 4.96 mg/dl DC vs. Δ -0.42 ± 6.47 mg/dl WC, Time × Treatment interaction p < .001), low-density lipoprotein (Δ -18.42 ± 17.13 mg/dl vs. Δ -2.05 ± 5.19 mg/dl WC, Time × Treatment interaction p < .001), AA/EPA ratio (Δ -5.26 ± 2.35; -54.1% DC vs. Δ -0.47 ± 0.73, -6.41% WC, Time × Treatment interaction p < .001) compared with WC group. In addition, 4 weeks of intervention showed a significant increase in high-density lipoprotein concentration in DC group (Δ + 3.26 ± 4.49 mg/dl DC vs. Δ -0.79 ± 5.12 mg/dl WC). Microbial communities in the DC group maintained a slightly higher microbial stability over time (exhibiting lower within-subject community dissimilarity)., Conclusion: Ingesting 30 g of dark chocolate over 4 weeks positively improved AA:EPA ratio and maintained gut microbial stability. Dark chocolate ingestion represents an effective nutritional strategy to improve blood lipid profiles in professional soccer players. What Are the Findings? Ingesting 30 g of dark chocolate for 4 weeks positively influences blood lipid AA: EPA ratio while maintaining gut microbial stability. What This Study Adds? Dietary intake of specific foods such as dark chocolate represents an alternative strategy to support the health and recovery of elite soccer players. What Impact Might This Have on Clinical Practice in the Future? From a clinical and translational perspective, dark chocolate ingestion positively modulates favorable blood lipid profiles and polyunsaturated fatty acid metabolism while maintaining gut microbial stability. Dark chocolate ingestion may be considered as an effective nutritional strategy in elite sport environments during periods of high-intensity training and congested competitions. Further research is required to determine functional outcomes associated with the observed improvements in blood lipid profiles.

In soccer, players must perform a variety of sport-specific skills usually during or immediately after running, often at sprint speed. The quality of the skill performed is likely influenced by the volume of work done in attacking and defending over the duration of the match. Even the most highly skilful players succumb to the impact of fatigue both physical and mental, which may result in underperforming skills at key moments in a match. Fitness is the platform on which skill is performed during team sport. With the onset of fatigue, tired players find it ever more difficult to successfully perform basic skills. Therefore, it is not surprising that teams spend a large proportion of their training time on fitness. While acknowledging the central role of fitness in team sport, the importance of team tactics, underpinned by spatial awareness, must not be neglected. It is well established that a high-carbohydrate diet before a match and, as a supplement during match play, helps delay the onset of fatigue. There is some evidence that players ingesting carbohydrate can maintain sport-relevant skills for the duration of exercise more successfully compared with when ingesting placebo or water. However, most of the assessments of sport-specific skills have been performed in a controlled, non-contested environment. Although these methods may be judged as not ecologically valid, they do rule out the confounding influences of competition on skill performance. The aim of this brief review is to explore whether carbohydrate ingestion, while delaying fatigue during match play, may also help retain sport soccer-specific skill performance., (© 2023. The Author(s).)

Introduction: Multidisciplinary and multi-professional collaboration is vital in providing better outcomes for patients The aim of the INTERACT-EUROPE Project (Wide Ranging Cooperation and Cutting Edge Innovation As A Response To Cancer Training Needs) was to develop an inter-specialty curriculum. A pilot project will enable a pioneer cohort to acquire a sample of the competencies needed., Methods: A scoping review, qualitative and quantitative surveys were undertaken. The quantitative survey results are reported here. Respondents, including members of education boards, curriculum committees, trainee committees of European specialist societies and the ECO Patient Advisory Committee, were asked to score 127 proposed competencies on a 7-point Likert scale as to their value in achieving the aims of the curriculum. Results were discussed and competencies developed at two stakeholder meetings. A consultative document, shared with stakeholders and available online, requested views regarding the other components of the curriculum., Results: Eleven competencies were revised, three omitted and three added. The competencies were organised according to the CanMEDS framework with 13 Entrustable Professional Activities, 23 competencies and 127 enabling competencies covering all roles in the framework. Recommendations regarding the infrastructure, organisational aspects, eligibility of trainees and training centres, programme contents, assessment and evaluation were developed using the replies to the consultative document., Conclusions: An Inter-specialty Cancer Training Programme Curriculum and a pilot programme with virtual and face-to-face components have been developed with the aim of improving the care of people affected by cancer., (© 2023 Published by Elsevier Ltd.)

In professional rugby union, it is common for players to switch between catered and non-catered dietary environments throughout a season. However, little is known about the difference in dietary intake between these two settings. Twelve elite male professional rugby union players (28.3 ± 2.9 y, 188.9 ± 9.5 cm, 104.1 ± 13.3 kg) from the New Zealand Super Rugby Championship completed seven-day photographic food diaries with two-way communication during two seven-day competition weeks in both catered and non-catered environments. While no significant differences were observed in relative carbohydrate intake, mean seven-day absolute energy intakes (5210 ± 674 vs. 4341 ± 654 kcal·day -1 ), relative protein (2.8 ± 0.3 vs. 2.3 ± 0.3 g·kgBM·day -1 ) and relative fat (2.1 ± 0.3 vs. 1.5 ± 0.3 g·kgBM·day -1 ) intakes were significantly higher in the catered compared to the non-catered environment (respectively) among forwards ( n = 6). Backs ( n = 6) presented non-significantly higher energy and macronutrient intakes within a catered compared to a non-catered environment. More similar dietary intakes were observed among backs regardless of the catering environment. Forwards may require more support and/or attention when transitioning between catered and non-catered environments to ensure that recommended dietary intakes are being achieved.

This study examined sweat rate, sweat sodium concentration [Na + ], and ad-libitum carbohydrate and fluid intakes in elite female soccer players during training ( n = 19) and a match ( n = 8); eight completed both for comparisons. Body mass (kg) was obtained before and after exercise to calculate sweat rate. The sweat [Na + ] was determined from absorbent patches on the thigh or back. Sweat rate, percentage body mass change, and sweat [Na + ] for 19 players during training were 0.47 ± 0.19 L·h -1 , +0.19 ± 0.65%, and 28 ± 10 mmol·L -1 , respectively. Sweat rate was higher during a match (0.98 ± 0.34 L·h -1 ) versus training (0.49 ± 0.26 L·h -1 , p = 0.007). Body mass losses were greater post-match (-1.12 ± 0.86%) than training (+0.29 ± 0.34%, p = 0.003). Sweat [Na + ] was similar for training (29 ± 9 mmol·L -1 ) and a match (35 ± 9 mmol·L -1 ) ( p = 0.215). There were no differences in match versus training carbohydrate intakes (2.0 ± 2.3 g·h -1 , 0.9 ± 1.5 g·h -1 , respectively, p = 0.219) or fluid intakes (0.71 ± 0.30 L·h -1 , 0.53 ± 0.21 L·h -1 , respectively, p = 0.114). In conclusion, female soccer players' sweat rates were higher during a match than during training, and carbohydrate intakes were below recommendations for matches and training.

Aim: This study examined test-retest reliability of soccer-specific skills within a modified version of the soccer match simulation (SMS) protocol., Methods: Ten professional youth academy soccer players (18 ± 1 years) from the United Kingdom completed 30 minutes of the modified SMS on two occasions under standardised conditions. During each trial, participants performed 20-m dribbling, short passing (4.2-m), long passing (7.9-m), shooting skills, and 15-m sprints within four blocks of soccer specific activity., Results: Collapsed normative data (mean (SD)) for trial 1 and trial 2 for dribbling speed was 2.7 (0.2) m/s, for sprint speed 5.9 (0.4) m/s, for short pass speed 11.1 (0.5) km/h, for long pass speed was 12.2 (0.5) km/h, and for shooting speed was 13.3 (0.4) km/h. Mean results from trial 1 and trial 2 were not different for all measures evaluated (P > 0.05). Good to excellent reliability (ICC 0.76-0.99) was observed for long and short passing speed, shooting speed, sprint speed, and long pass accuracy, with CVs typically < 5-10%. Moderate reliability (ICC 0.50-0.75) was observed for dribbling speed. Poor reliability (ICC <0.50) was observed for dribbling accuracy and shooting accuracy., Conclusions: The reliability of the modified version of the SMS protocol is promising for most of the skills assessed, with the exception of dribbling and shooting accuracy in this group of professional youth soccer players. The modified protocol is easy to implement within professional clubs without specialist equipment, but due to the limited sample size the reliability requires further confirmation in a larger sample.

Sports nutrition is a relatively new discipline; with ~100 published papers/year in the 1990s to ~3,500+ papers/year today. Historically, sports nutrition research was primarily initiated by university-based exercise physiologists who developed new methodologies that could be impacted by nutrition interventions (e.g., carbohydrate/fat oxidation by whole body calorimetry and muscle glycogen by muscle biopsies). Application of these methods in seminal studies helped develop current sports nutrition guidelines as compiled in several expert consensus statements. Despite this wealth of knowledge, a limitation of the current evidence is the lack of appropriate intervention studies (e.g., randomized controlled clinical trials) in elite athlete populations that are ecologically valid (e.g., in real-life training and competition settings). Over the last decade, there has been an explosion of sports science technologies, methodologies, and innovations. Some of these recent advances are field-based, thus, providing the opportunity to accelerate the application of ecologically valid personalized sports nutrition interventions. Conversely, the acceleration of novel technologies and commercial solutions, especially in the field of biotechnology and software/app development, has far outstripped the scientific communities' ability to validate the effectiveness and utility of the vast majority of these new commercial technologies. This mini-review will highlight historical and present innovations with particular focus on technological innovations in sports nutrition that are expected to advance the field into the future. Indeed, the development and sharing of more "big data," integrating field-based measurements, resulting in more ecologically valid evidence for efficacy and personalized prescriptions, are all future key opportunities to further advance the field of sports nutrition., Competing Interests: IR and MK are employees of the Gatorade Sports Science Institute, a division of PepsiCo, Inc. KJ, TS, and YP, received speaking honoraria, for the GSSI ECSS 2021 pre-conference symposium which inspired this article. YP is the founding member of the Sub2 project (www.sub2hrs.com). The Sub2 project is affiliated to a non-trading company (Athlome Limited, UK) that is minor (<1.1%) shareholder of Maurten AB, Gothenburg, Sweden., (Copyright © 2022 Jonvik, King, Rollo, Stellingwerff and Pitsiladis.)

Skeletal muscle mass losses with age are associated with negative health consequences, including an increased risk of developing metabolic disease and the loss of independence. Athletes adopt numerous nutritional strategies to maximize the benefits of exercise training and enhance recovery in pursuit of improving skeletal muscle quality, mass, or function. Importantly, many of the principles applied to enhance skeletal muscle health in athletes may be applicable to support active aging and prevent sarcopenia in the healthy (non-clinical) aging population. Here, we discuss the anabolic properties of protein supplementation in addition to ingredients that may enhance the anabolic effects of protein (e.g. omega 3 s, creatine, inorganic nitrate) in older persons. We conclude that nutritional strategies used in pursuit of performance enhancement in athletes are often applicable to improve skeletal muscle health in the healthy older population when implemented as part of a healthy active lifestyle. Further research is required to elucidate the mechanisms by which these nutrients may induce favourable changes in skeletal muscle and to determine the appropriate dosing and timing of nutrient intakes to support active aging., (© 2021. The Author(s).)

Female soccer has seen a substantial rise in participation, as well as increased financial support from governing bodies over the last decade. Thus, there is an onus on researchers and medical departments to develop a better understanding of the physical characteristics and demands, and the health and performance needs of female soccer players. In this review, we discuss the current research, as well as the knowledge gaps, of six major topics: physical demands, talent identification, body composition, injury risk and prevention, health and nutrition. Data on female talent identification are scarce, and future studies need to elucidate the influence of relative age and maturation selection across age groups. Regarding the physical demands, more research is needed on the pattern of high-intensity sprinting during matches and the contribution of soccer-specific movements. Injuries are not uncommon in female soccer players, but targeting intrinsically modifiable factors with injury prevention programmes can reduce injury rates. The anthropometric and physical characteristics of female players are heterogeneous and setting specific targets should be discouraged in youth and sub-elite players. Menstrual cycle phase may influence performance and injury risk; however, there are few studies in soccer players. Nutrition plays a critical role in health and performance and ensuring adequate energy intake remains a priority. Despite recent progress, there is considerably less research in female than male soccer players. Many gaps in our understanding of how best to develop and manage the health and performance of female soccer players remain.

Intestinal barrier integrity and function are compromised during exertional heat stress (EHS) potentially leading to consequences that range from minor gastrointestinal (GI) disturbances to fatal outcomes in exertional heat stroke or septic shock. This mini-review provides a concise discussion of nutritional interventions that may protect against intestinal permeability during EHS and suggests physiological mechanisms responsible for this protection. Although diverse nutritional interventions have been suggested to be protective against EHS-induced GI permeability, the ingestion of certain amino acids, carbohydrates, and fluid per se is potentially effective strategy, whereas evidence for various polyphenols and pre/probiotics is developing. Plausible physiological mechanisms of protection include increased blood flow, epithelial cell proliferation, upregulation of intracellular heat shock proteins, modulation of inflammatory signaling, alteration of the GI microbiota, and increased expression of tight junction (TJ) proteins. Further clinical research is needed to propose specific nutritional candidates and recommendations for their application to prevent intestinal barrier disruption and elucidate mechanisms during EHS.

This study aimed to assess energy availability (EA), alongside possible risk factors of reduced or low EA of professional female soccer players during a competitive season. Thirteen players (age: 23.7 ± 3.4 y, stature: 1.69 ± 0.08 m, body mass: 63.7 ± 7.0 kg) engaged in a 5-day (two rest days, one light training, heavy training and match day) monitoring period. Energy intake (EI) and expenditure during exercise (EEE) were measured. EA was calculated and categorised as optimal, reduced or low (>45, 30-45, <30 kcal·kg FFM -1 ·day -1 , respectively). Relationships between EA and bone mineral density, resting metabolic rate (RMR), plasma micronutrient status, biochemical markers and survey data were assessed. EA was optimal for 15%, reduced for 62% and low for 23% of players. Higher EA was observed on rest days compared to others ( P <0.05). EA was higher for the light compared to the heavy training day ( P <0.001). EEE differed significantly between days ( P <0.05). EI (2124 ± 444 kcal), carbohydrate (3.31 ± 0.64 g·kg·day -1 ) and protein (1.83 ± 0.41 g·kg·day -1 ) intake remained similar ( P >0.05). Survey data revealed 23% scored ≥ 8 on the Low Energy Availability in Females Questionnaire and met criteria for low RMR (ratio <0.90). Relationships between EA and risk factors were inconclusive. Most players displayed reduced EA and did not alter EI or carbohydrate intake according to training or match demands. Although cases of low EA were identified, further work is needed to investigate possible long-term effects and risk factors of low and reduced EA separately to inform player recommendations.

Aim: The purpose of this study was to evaluate hydration status, fluid intake, sweat rate, and sweat sodium concentration in recreational tropical native runners., Methods: A total of 102 males and 64 females participated in this study. Participants ran at their self-selected pace for 30-100 min. Age, environmental conditions, running profiles, sweat rates, and sweat sodium data were recorded. Differences in age, running duration, distance and pace, and physiological changes between sexes were analysed. A p -value cut-off of 0.05 depicted statistical significance., Results: Males had lower relative fluid intake (6 ± 6 vs. 8 ± 7 mL·kg -1 ·h -1 , p < 0.05) and greater relative fluid balance deficit (-13 ± 8 mL·kg -1 ·h -1 vs. -8 ± 7 mL·kg -1 ·h -1 , p < 0.05) than females. Males had higher whole-body sweat rates (1.3 ± 0.5 L·h -1 vs. 0.9 ± 0.3 L·h -1 , p < 0.05) than females. Mean rates of sweat sodium loss (54 ± 27 vs. 39 ± 22 mmol·h -1 ) were higher in males than females ( p < 0.05)., Conclusions: The sweat profile and composition in tropical native runners are similar to reported values in the literature. The current fluid replacement guidelines pertaining to volume and electrolyte replacement are applicable to tropical native runners.

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts., Competing Interests: Competing interests: JC has received payment for sports nutrition consultancy work with Arsenal Football Club, England Football Association and France Football Federation. Through his consultancy he also receives payment for nutrition services with individuals and corporate organisations. He is author of a book (The Energy Plan) for which he receives payment from Penguin Random House. He has written articles for BBC Good Food for which he has received payment. He co-authored an article in 2014 and presented at European College of Sports Sciences in 2019 for The Gatorade Sports Science Institute, for which he received honoraria. He has received travel and accommodation expenses to speak at conferences over the past 5 years including; UEFA Medical Symposium, Isokinetic Football Medicine Strategies, Swedish Sports Medicine Congress and International Sport & Exercise Nutrition Conference. He is a council member and past president of The Royal Society of Medicine’s Food & Health Forum. He received from UEFA the cost of flight and accommodation to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript.” He did not receive any other form of financial support directly related to this manuscript. RM holds an honorary (unpaid) professorship at the School of Medicine, St Andrews University, Scotland. He holds visiting (unpaid) professorships at Stirling University and at the Chinese University of Hong Kong. He is co-author of two books published by Oxford University Press (Biochemistry of Exercise and Training; The Biochemical Basis of Sports Performance) for which he receives royalties. He is Program Director on the IOC Diploma programs in Sports Medicine, Sports Nutrition and Sports Physical Therapies, for which he receives honoraria and additionally contributes lectures to those programs, for which he has received honoraria. He was a member of the Expert Scientific Committee of the IOC Medical and Scientific Commission. This position was unpaid, but travel to meetings and accommodation were provided. He contributed a scientific review to a meeting of the Gatorade Sports Science Institute in Texas in March 2019: travel and accommodation were paid and an honorarium was received for participation in the meeting and for preparation of a summary paper for publication in the SSI Sports Science Exchange. He participated in an ACSM online podcast in 2019 for which an honorarium was received. He participated in a sports medicine education meeting organised by the Medical Committee of the German Football Federation in Frankfurt in January 2020: travel expenses and an honorarium were paid. He has participated in numerous other international sports nutrition symposia between 2015 and the present for which travel and accommodation were provided. He received from UEFA the cost of flight and accommodation to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript.” He did not receive any other form of financial support directly related to this manuscript. MG is co-author of two books published by Oxford University Press (Biochemistry of Exercise and Training; The Biochemical Basis of Sports Performance) for which he receives royalties. He is also co-author of 3 other books; one published by Human Kinetics (Sport Nutrition), one published by Routledge (Exercise Immunology) and the other by Meyer & Meyer Sport (Eat, Move, Sleep, Repeat; Beating Type 2 Diabetes) all of which he receives royalties for. He has contributed to several recorded lectures for which he received honoraniums for; 2020 to the IOC Diploma program Sports Nutrition, 2020 to the Nutrition Society Training Academy, 2020 to the My Sport Science Academy. He was a member of the IOC Expert Scientific Group on training load and illness/injury in 2015. This position was unpaid, but travel to a meeting and accommodation were provided. Other international symposia were attended as speaker where honorarium was paid plus travel and accommodation; Japan, 2016, London 2015, Barcelona 2015, Vienna, 2015. Mike also contributed a scientific review on nutrition, exercise and immune function for a sport nutrition company, NutritionX, in 2020 for which an honorarium was received. He has received complimentary tickets for Leicester City FC football matches for occasional nutrition consultancy advice but no honoraria were received. He has spoken at a number of other conferences, symposia and other events within the last five years: travel and accommodation were provided for most of these, but no record has been kept. He did not receive any form of financial support directly related to this manuscript. JB has presented at the Arsenal Sports & Exercise Medicine conference in London, UK, where travel and accommodation were paid by Arsenal FC. He has co-authored two chapters in the book, ‘The Science and Application of High-intensity interval training (HIIT) with no honorarium nor any royalties received. He did not receive any form of financial support directly related to this manuscript. AJ holds a visiting professorship at the Loughborough University, UK and is director of mysportscience. He is also co-founder and CEO of CORE Nutrition planning. He is author of a book sport nutrition by Human Kinetics for which he receives royalties. He is board member of the IOC Diploma programs in Sports Medicine. Asker worked as a consultant for the Dutch Olympic Committee NOC*NSF, Red Bull Leipzig, FC Barcelona, PSV Eindhoven, Athletic Club de Bilbao, US Soccer, Red Bull Athlete Performance Center, Jumbo Visma Pro cycling, Universidad d’Europea de Madrid, University of Barcelona, CAR, VIC University, Hiddit, SinSeb, Enervit, Volanthen, Friesland Campina, Nutrition Society, Clif, Snelle Jelle, Jumbo Supermarkten, PepsiCo, Unit Nutrition, BF Eventos, Mexican sports nutrition federation and the Turkish sports nutrition federation. Travel expenses and an honorarium were paid. He has participated in numerous other international sports nutrition symposia between 2015 and the present for which travel and accommodation were provided. He did not receive any form of financial support directly related to this manuscript. JM has received research grants from UEFA, Science in Sport, Lucozade Ribena Suntory, GlaxoSmithKline, Liverpool Football Club, Everton Football Club, British Horseracing Authority, Racing Welfare Foundation, Port Adelaide FC, English Institute of Sport and MuscleSound. He has received paid consultancy for Liverpool Football Club, Team Sky, Healthspan Elite, FA Premier League, Irish Football Association, The Football Association, Rangers FC and Science in Sport. He is the current Director of Performance Solutions for Science in Sport. He is the co-author of the textbook Biochemistry for Sport and Exercise Metabolism and receives annula royalties form Wiley. He has received travel and accommodation costs to speak at over 50 conferences in the last 5 years. He did not receive any form of financial support directly related to this manuscript. SP reports personal fees from Enhanced Recovery (donated to charity), equity from Exerkine (donated to charity), grants from Canadian Institutes of Health Research, grants from National Science and Engineering Council, personal fees (Travel and Honorarium, 2018) from US National Dairy Council, personal fees from US Dairy Export Council (Traval and Honorarium, 2019), personal fees from Leprino Foods (2017), personal fees from Agropur (2018), grants from Alliance for Potato Research and Education, grants from US National Dairy Council, outside the submitted work; In addition, Dr. Phillips has a patent 3052324 (Canadian) issued to Exerkine, a patent 16/182891 (US) pending to Exerkine, and a patent 2018157258 (Worldwide) pending to Exerkine. He did not receive any form of financial support directly related to this manuscript. LA received honoraria as an occasional consultant and reimbursement for travel expenses from the Drinking Water Research Foundation, Alexandria, VA, USA and from Danone Nutricia Research, France. He previously received research grant funding from both organizations. He formerly served as the elected President of the American College of Sports Medicine (unpaid), 2015-2016. He received honoraria and reimbursement of travel expenses from five universities and the Texas Regional Chapter of the American College of Sports Medicine during a speaking tour in 2018. He presently serves as a member of the Medical & Science Advisory Board, Korey Stringer Institute, University of Connecticut, USA (unpaid). Professor Armstrong received no financial support for participating in this manuscript. LB is an author or editor of textbooks on sports nutrition for which she receives royalties. She is a Program Director and contributor to the IOC Diploma programs in Sports Nutrition for which she receives honoraria. Prior to June 2020 she was Head of Sports Nutrition and Chief of Nutrition Strategy at the Australian Institute of Sport, where her representation at numerous international sports nutrition symposia and workshops was generally undertaken within her job description and any travel reimbursements and honoria were provided to the AIS. Presentations during the period of 2015-2020 in which the activity and its support were undertaken as private consultancy include: 2015 Berlin Marathon powerbar conference; 2019 ACSM meeting and pre-conference GSSI workshop (supported by the International Association of Athletics Federation and Gatorade); 2019 Northern Ireland Workshop on Sports Nutrition (supported by Dairy Council Northern Ireland) and the 2016 SCAN conference and 2019 FNCE conference (supported by the Academy of Nutrition and Dietetics). She has received a research grant from the Alliance of Potato Research and Education. She did not receive any form of financial support directly related to this manuscript. GC has previously received payment for nutrition consultancy at Everton, Nottingham Forest and West Bromwich Albion and Aston Villa Football clubs, Munster Rugby, England Rugby The Lawn Tennis Association The Football Association, The English Institute of Sport and The Saudi Arabian Olympic Association and The European Tour Golf. He currently advises HealthSpan Elite and NutritionX for which he receives an honorarium and in the past has advised GetBuzzing bars. GC has spoken on several occasions for GSSI and produced articles for their exchange series for which he received an honorarium. He has spoken at a number of other conferences, symposia and other events within the last five years: travel and accommodation were provided for most of these, but no record has been kept. GC currently or has previous received research grants from the MRC, BSSRC, GSK, Sirtris, Research into Ageing, Aliment Nutrition, Naturecan, HH Sheikh Mansour Bin Zayad Al Nahyan Global Arabian Horse Flat Racing Festival, The Racing Foundation, The British Horse Racing Association, The Rugby Football Union, The Lawn Tennis Association, Newport Gwent Dragons, Gloucester Rugby, Everton FC, Aston Villa FC. GC has delivered guest lectures for the IOC diploma in Sport Nutrition and The Football Science Institute for which he received an honorarium. GC has previously performed consultancy work for Callaway Golf and Quooker Taps. He did not receive any form of financial support directly related to this manuscript. RD receives is Joint Head of Research & Development at Football Federation Australia and is paid for this role. He has received travel and accommodation funding to speak / present at several international congress, including; the Football Science Institute, Football Federation Australia, Tennis Australia, Brazil National Football Federation, UFSC Brazil, Canadian Institute of Sport, Bristol City FC and UdS Germany. He is not affiliated or received any travel, accommodation, funding from any nutrition company in the last 10 years. He did not receive any form of financial support directly related to this manuscript. EL-M is author of a book published by Human Kinetics (Plant-Based Sports Nutrition: Expert Fueling Strategies for Training, Recovery, and Performance) for which she receives royalties. She was a member of the Dietary Supplements and the High-Performance Athlete Expert Scientific Committee of the IOC Medical and Scientific Commission in 2017; this committee assignment was unpaid, but travel to the group meeting and accommodation were provided. She contributed scientific presentations to a meeting of the Gatorade Sports Science Institute in Florida in Oct 2017 and Gatorade at NFL Combine in Feb 2020: travel and accommodation were paid and an honorarium was received for participations at both meetings and for preparation of a summary paper for publication in the SSI Sports Science Exchange in 2018. She presented at a Danone Essential Dairy and Plant-Based Proteins Board Meeting in New York in July in 2019 for which travel, accommodations and an honorarium were paid. She has participated in numerous other national nutrition and medical conferences between 2015 and the present for which travel and accommodation and typically an honorarium were received. She did not receive any form of financial support directly related to this manuscript. JL has received payment for sport nutrition consultancy work with French Football Federation, Liverpool Football Club, Lille Football Club, Paris-Dakar association. He has received travel/accommodation funding and honorariums to speak / present at several national/international conferences between 2015 to present) including: Research day of the Dairy Council UK; European College of Sport and Exercise Physicians, Paris, France; International conference of Sports Physiotherapy, Kuala Lumpur, Malaysia; French Football Federation congress for S&C coaches, Paris; congress of the Mexican Nutrition Society, Guadalajara; and congress of the Swiss Nutrition society, Nottwil. He has contributed to several recorded lectures for which he received honorariums for the IOPN Diploma, London, UK. He co-supervised a PhD project funded by a nutrition company (Lactalis, Laval, France). He did not receive any form of financial support directly related to this manuscript. DM has no conflicts to disclose. He did not receive any form of financial support directly related to this manuscript. FM is the main editor of a book published by CRC Press, Taylor & Francis Group (Fluid Balance, Hydration and Athletic Performance) for which she receives royalties. She hold a visiting professor position at the Human Movement Graduate Program from 2018 to 2020 (unpaid) at the Federal University of Rio Grande do Sul. She did not receive any form of financial support directly related to this manuscript. IR is an employee of the Gatorade Sports Science Institute (GSSI), a division of PepsiCo, Incorporated. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Incorporated. Ian leads the FC Barcelona, innovation hub certificate in sports nutrition, he is co-author on the FC Barcelona Sports Nutrition guide for Football and co-organises the FCB conference in Sports nutrition, all as part of his role with GSSI. Ian co-authored a chapter on nutrition in the book “Elite Soccer Players” with no honorarium nor any royalties received. He not receive any form of financial support directly related to this manuscript. JSB holds a professorship at the Norwegian School of Sports Science in Oslo Norway. She receives research grants from The Norwegian Woman's Public Health Association, the Norwegian Extra Foundation for Health and Rehabilitation, The Norwegian Association of Youth Mental Health, and the Dam Foundation and TINE SA. She has contributed with lectures for the IOC Diploma programs in Sports Medicine and Sports Nutrition and receives honoraria for about one lecture per year. She was a member of the Expert Scientific Committee of the IOC Medical and Scientific Commission. She has also been a member in IOC working group (position papers). These positions were unpaid, but travel to meetings and accommodation were provided. She is also an International trustee (ACSM) and Vice president in Nordic Eating Disorder Society. These positions are unpaid, but travel to meetings and accommodation are provided. BW Received honorarium for consultancy with Nutricia. BW is the editor of one book (carnitine metabolism and human nutrition) published by CRC press for which he receives royalties. He has made lecture contributions to the International Society for Sports and Exercise Conference (ISENC), Nutrition Society, European Society for Parenteral and Enteral Nutrition (ESPEN) and Physiological Society which were unpaid for which he received expenses. He has received travel and expenses for an organised symposium (by Ketchum PR, US) at American Society for Nutrition (ASN) and the Reducetarian Conference. He has received payments from various UK universities for external examining with the last 5 years. He did not receive any form of financial support directly related to this manuscript. BB is co-author of two books, one published by McGrawHill (Nutrición Deportiva) for which she receives royalties and another one published by Organización Panamericana de la Salud (La Receta de los Campeones) for which she received royalties in the past. She is Program Director on the FMND-Nutrinfo Curse in Sports Nutrition, for which she receives honoraria and additionally contributes with one lectures to these program, for which she has received honoraria. She has participated in numerous international sports nutrition symposia between 2011 and the present for which travel and accommodation were paid by The Mexican Football Federation. She advises The Coca Cola Company for issues related to their Sport Beverage Powerade since 2012 for which she receives honoraria. She did not receive any form of financial support directly related to this manuscript. GD is head of performance for CF Real Madrid. He holds visiting (unpaid) professorships at Liverpool John Moores University He previously worked for the French Football Federation, Lille FC and the universities of Artois and Lille. He is co-author of a book on training methodology and performance (2007, three chapters (monitoring fatigue and recovery, Thieme eds, 2017; Targeted Systems of the Body for Training in Football Science, Human Kinetics, 2016; Boosting Aerobic Performance in High-Performance training for Sports, Human Kinetics, 2016), for which he received royalties. He has lectured for Aspetar twice (2013, 2016) recovery and nutrition courses for which he has received travel expenses, accommodation and an honorarium. He has spoken at 33 international conferences on sports science and football for which he has received travel expenses and accommodation, no honorariums have been received. He did not receive any form of financial support directly related to this manuscript. MAL: Toña is Professor of the Human Nutrition and Dietetics degree at the University of Barcelona and Nutritional Advisor of FCB. She is involved in clinical consultation and advice to competitive athletes and she did not receive any form of financial support directly related to this manuscript. PR is currently employed by the Dutch Olympic Team. He was formerly employed by AFC Ajax Amsterdam. He is owner of PR Sportvoedingsadvies. Through his consultancy he also receives payment for nutrition services with individuals and corporate organisations. He co-authored an article for The Gatorade Sports Science Institute, for which he received honoraria. He received honoraria as an invited speaker for the Barça Sport Nutrition Conference and FrieslandCampina Institute congress “sport en voeding”. He did not receive any form of financial support directly related to this manuscript. MB has received travel and accommodation funding (from the organizers and/or the Schulthess Clinic) to speak/present at several international congress between 2015 to present, including: the Isokinetic Football Medicine Strategies Conferences (2015-2019, London & Barcelona), Team Concept Conference 2016 (Las Vegas), the IOC World Conference 2017, the World Conference of Sports Physical Therapy (Belfast 2017, Vancouver 2019), the Salzburg Sports PT Congress 2019, the ACL Consensus Meeting (Pittsburgh 2019), the International Conference on Football Refereeing (Lisbon 2019), the International Society of Hip Arthroscopy Physiotherapy Meeting (Madrid 2019). As a member of F-MARC (2002- 2016) he received compensation from FIFA for his work during this time, but no other compensations or grants have been received. Between 2015 and 2019 he has authored/co-authored nine book chapters (football medicine, sports medicine) with no honorarium nor any royalties received. He did not receive any form of financial support directly related to this manuscript. CC: Since 2007 I have been invited in international conference/seminar by FIFA and UEFA for lectures on refereeing receiving no honorary but having paid travels, accommodation and daily expenses. I did not receive any form of payment for the contribution to this manuscript. CC has not received any honorarium from any company in the last 5 years. She is employed by the Football Association and has a private medical practice. She is member of the UEFA medical committee and have paid expenses (travel & accommodation) for UEFA medical committee meetings. She received from UEFA the cost of flight and accommodation to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript.” She did not receive any other form of financial support directly related to this manuscript. MD: The travel to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript was paid by UEFA. No other conflicts to declare. He did not receive any other form of financial support directly related to this manuscript. HG has received honorarium and reimbursement of travel and accommodation expenses for expert statements in doping cases in connection with nutritional supplements for several federations and anti-doping organisations, including UEFA and FIFA and several National Anti-Doping Agencies. He has received daily fees and reimbursement of travel and accommodation expenses for his participation in WADA expert groups for the athlete biological passport. He has received honorarium and reimbursement of travel and accommodation expenses for lectures about doping risks of nutritional supplements in congresses of several medical societies. He has received reimbursement of travel and accommodation expenses for his participation at the IOC consensus conference about nutritional supplements. The travel to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript was paid by UEFA. No other conflicts to declare. He did not receive any other form of financial support directly related to this manuscript. TM has never received any royalties or fees from nutritional companies or other relevant sources. For none of his publications has he ever received any financial compensation except for one article about the management of infectious diseases in the Aspetar Sports Medicine Journal. He received from UEFA the cost of flight and accommodation to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript.” He did not receive any other form of financial support directly related to this manuscript. NP: The travel to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript was paid by UEFA. No other conflicts to declare. She did not receive any other form of financial support directly related to this manuscript. MV: The travel to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript was paid by UEFA. No other conflicts to declare. He did not receive any other form of financial support directly related to this manuscript. AM has received a grant from FIFA to investigate health and performance of footballers during the transition from club to national teams. He has received travel and accommodation funding to speak / present at several international congress between 2015 to present), including; the Isokinetic Football Medicine Strategies Conference (London and Barcelona), KNVB national federation, Danish SportsKongress, Denmark, Sportsfisio congress, Switzerland, The Barça Innovation Hub, Barcelona, Spain. Oslo Sports Trauma Research Group, Oslo, Norway. Mapei Research Centre, Bergamo, Italy. Brazil National Football Federation, Rio, Brazil, French Football Federation, Paris, France. He is not affiliated or received any travel, accommodation, funding from any nutrition company. He also received consultancy fee from the French Football Federation for injury prevention recommendations for the 2018 FIFA World Cup. He received from UEFA the cost of flight and accommodation to attend an Expert Group Meeting with the UEFA Medical Committee in Brussels, Belgium, to discuss preparation of this manuscript.” He did not receive any other form of financial support directly related to this manuscript., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: See COI document linked to the main paper (too large to copy paste in here).

Hypohydration increases physiological strain and reduces physical and technical soccer performance, but there are limited data on how fluid balance responses change between different types of sessions in professional players. This study investigated sweat and fluid/carbohydrate intake responses in elite male professional soccer players training at low and high intensities in cool and hot environments. Fluid/sodium (Na + ) losses and ad-libitum carbohydrate/fluid intake of fourteen elite male soccer players were measured on four occasions: cool (wet bulb globe temperature (WBGT): 15 ± 7 °C, 66 ± 6% relative humidity (RH)) low intensity (rating of perceived exertion (RPE) 2-4, m·min -1 40-46) (CL); cool high intensity (RPE 6-8, m·min -1 82-86) (CH); hot (29 ± 1 °C, 52 ± 7% RH) low intensity (HL); hot high intensity (HH). Exercise involved 65 ± 5 min of soccer-specific training. Before and after exercise, players were weighed in minimal clothing. During training, players had ad libitum access to carbohydrate beverages and water. Sweat [Na + ] (mmol·L -1 ), which was measured by absorbent patches positioned on the thigh, was no different between conditions, CL: 35 ± 9, CH: 38 ± 8, HL: 34 ± 70.17, HH: 38 ± 8 ( p = 0.475). Exercise intensity and environmental condition significantly influenced sweat rates (L·h -1 ), CL: 0.55 ± 0.20, CH: 0.98 ± 0.21, HL: 0.81 ± 0.17, HH: 1.43 ± 0.23 ( p =0.001), and percentage dehydration ( p < 0.001). Fluid intake was significantly associated with sweat rate ( p = 0.019), with no players experiencing hypohydration > 2% of pre-exercise body mass. Carbohydrate intake varied between players (range 0-38 g·h -1 ), with no difference between conditions. These descriptive data gathered on elite professional players highlight the variation in the hydration status, sweat rate, sweat Na + losses, and carbohydrate intake in response to training in cool and hot environments and at low and high exercise intensities.

Objectives: To quantify self-reported current sleep behaviors in a range of adult athletes. In addition, to determine any differences in sleep duration and sleep quality, depending on sport type and competitive level., Material and Methods: In this cross-sectional study, 313 athletes (243 male, 70 female), competing in a variety of sports and competitive level, completed the Pittsburgh sleep quality index (PSQI) and a questionnaire which captured current sleep behaviors. Sleep quality was calculated using the global PSQI score (≥ 5 indicative of poor sleep quality)., Results: On average, athletes self-reported sleep duration was 7:34 ± 1:00 h:min. Overall, 19% of athletes achieved less than 7 h of sleep, 50% achieved less than 8 h. Global PSQI score was 5.0 ± 2.4, with poor sleep quality found in 55% of athletes. Sleep duration was significantly shorter in runners compared to basketball, soccer and rugby players (p < 0.05). Recreational athletes slept significantly less (7:08 ± 0:54 h:min) than competitive (7:32 ± 1:00 h:min), national (7:50 ± 1:00 h:min) and elite level athletes (7:49 ± 0:51 h:min). No differences in sleep quality were found between sport or competitive level., Discussion: Half of the athletes failed to achieve 8 h of sleep per night and the majority reported compromised sleep quality. Sport type and competitive level may influence sleep duration; however, these factors do not seem to cause discrepancies in sleep quality. This study provides novel data into the sleep behaviors of adult athletes, and suggests strategies to improve sleep duration and quality may be warranted.

Gut microbiome influences athletes' physiology, but because of the complexity of sport performance and the great intervariability of microbiome features, it is not reasonable to define a single healthy microbiota profile for athletes. We suggest the use of specific meta-omics analysis coupled with innovative computational systems to uncover the hidden association between microbes and athlete's physiology and predict personalized recommendation.

The purpose of this current opinion paper is to describe the journey of ingested carbohydrate from 'mouth to mitochondria' culminating in energy production in skeletal muscles during exercise. This journey is conveniently described as primary, secondary, and tertiary events. The primary stage is detection of ingested carbohydrate by receptors in the oral cavity and on the tongue that activate reward and other centers in the brain leading to insulin secretion. After digestion, the secondary stage is the transport of monosaccharides from the small intestine into the systemic circulation. The passage of these monosaccharides is facilitated by the presence of various transport proteins. The intestinal mucosa has carbohydrate sensors that stimulate the release of two 'incretin' hormones (GIP and GLP-1) whose actions range from the secretion of insulin to appetite regulation. Most of the ingested carbohydrate is taken up by the liver resulting in a transient inhibition of hepatic glucose release in a dose-dependent manner. Nonetheless, the subsequent increased hepatic glucose (and lactate) output can increase exogenous carbohydrate oxidation rates by 40-50%. The recognition and successful distribution of carbohydrate to the brain and skeletal muscles to maintain carbohydrate oxidation as well as prevent hypoglycaemia underpins the mechanisms to improve exercise performance.