International Association of Athletics Federations Consensus Statement 2019: Nutrition for Athletics

The Race Within a Race: Starting Together, Finishing Apart

Every four years the world's best athletes come together to compete in the Olympic games, electrifying audiences with incredible feats of speed, strength, endurance and skill as personal best performances and new records are set. However, the exceptional talent that underpin such performances is incomprehensible to most casual observers who often cannot appreciate how unique these athletes are. In this regard, endurance running, specifically the marathon, a 42.195 km foot race, provides one of the few occasions in sport outside of Olympic, world and national competitions, that permits sport scientists and fans alike to directly compare differences in the physiology between recreational and elite competitors. While these individuals may all cover the same distance, on the same course, on the same day - their experience and the physiological and psychological demands placed upon them are vastly different. There is, in effect, a "race within a race". In the current review we highlight the superior physiology of the elite endurance athlete, emphasizing the gap between elite competitors and well-trained, but less genetically endowed athletes. We draw attention to a range of inconsistencies in how current sports science practices are understood, implemented, and communicated in terms of the elite and not-so-elite endurance athlete.

Validation of a sports nutrition knowledge questionnaire for Sri Lankan track and field athletes

BACKGROUND

While several validated sports nutrition knowledge questionnaires exist, none are specifically designed to assess the sports nutrition knowledge (SNK) of Sri Lankan track and field athletes. This study aims to validate the Sri Lankan Sports Nutrition Knowledge Questionnaire (SLn-SNKQ), tailored for this athlete group, to provide more accurate and meaningful insights for research and practice. This will enable health professionals and coaches to confidently assess athletes' nutrition knowledge, which directly influences their food choices.

METHODS

The validity of the questionnaire was established through a multi-step approach. Content validity was achieved via ratings from nutrition experts, all of whom had specialized training in human nutrition and experience of working with athletes. Face validity was evaluated through in-depth telephone interviews with elite or highly trained athletes, using a retrospective think-out-loud protocol to gather feedback on the clarity and relevance of the questions. Construct validity involved nutrition-trained doctors (NTG), non-nutrition-trained professionals (NNTG), and elite-level athletes' groups (AG). Internal consistency was assessed using Cronbach's alpha, and test-retest reliability was evaluated.

RESULTS

The final tool comprised 123 individual statements or prompts (items) that were organized into 32 broader questions, spanning 12 sub-sections. Content validity was confirmed by fully integrating 49 out of 70 comments and partially integrating four comments received from nutrition experts for each sub-section. Face validity was established by fully integrating 33 out of 40 comments received from 16 elite and highly trained athletes. Construct validity was confirmed, indicating significant differences in the total scores achieved as a percentage of the SLn-SNKQ among the NTG (462.5, 92.5%), NNTG (223.5, 44.7%), and AG (235, 47.0%; p < 0.001). Reproducibility was established by strong test-retest reliability between individuals' scores on two test attempts, three weeks apart (spearman's correlation; ρ = 0.99, p < 0.05). Internal reliability for each sub-section met psychometric reliability requirements (Cronbach's α > 0.7).

CONCLUSIONS

The SLn-SNKQ has been validated and demonstrates robust psychometric properties, offering a reliable tool for assessing SNK among Sri Lankan track and field athletes.

No evidence of improvements in energy metabolism after 1 week of nitrate and citrulline co-supplementation in elite rowers

PURPOSE

Citrulline (CIT) and beetroot extract (BR) supplements positively impacts exercise performance in elite rowers. However, its influence on metabolic outcomes such as whole-body volumes of oxygen consumption (VO2) and carbon dioxide production (VCO2), substrate oxidation, energy expenditure (EE), and gross efficiency remains unknown. We studied the effects of 1 week of daily co-supplementation of 3.5 g BR (500 mg NO3-) plus 6 g CIT on VO2 and VCO2 kinetics, substrate utilization, EE, and gross efficiency in elite male rowers compared to a placebo and to a BR supplementation.

METHODS

Twenty elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1 week of supplementation in each group of study: Placebo (PLAG); BRG; and BR-CITG. Efficiency (70% VO2max) and performance (incremental maximal) tests were performed, and gas-exchange data were collected via indirect calorimetry.

RESULTS

Analysis of covariance (ANCOVA) showed no mean between-condition differences on respiratory exchange ratio (RER), EE, and gross efficiency in the efficiency test (all P > 0.06), and in the performance test (all P > 0.28). Moreover, in both tests no interaction Time × Supplement effects were observed for VO2, VCO2, RER, EE, substrate oxidation, and, gross efficiency (all P > 0.12).

CONCLUSION

After 1 week, no effects on energy metabolism and substrate utilization were observed after the daily co-ingestion of BR extract plus CIT supplement, therefore longer (> 7 days) and higher doses of supplementation might be needed to influence metabolism.

Papadopoulou S. Association of Competitive Adolescent Athletes from Lean and Non-Lean Sports Physical, Social and Psychological Characteristics with Adherence to Mediterranean Diet

Mediterranean diet (MD) is regarded as one of the healthier dietary patterns which is recommended for athletes. This study aims to investigate the adherence to the Mediterranean diet (AMD) and associated beliefs in a large, diverse sample of competitive adolescent athletes from various sports, including both lean and non-lean sports. Additionally, the study examines factors important regarding intention to AMD within the Theory of Planned Behavior (TPB). In the study took part 711 adolescents (357 male, aged = 14.93 ± 1.38, and 354 female, aged = 14.85 ± 1.35) athletes. The level of AMD was not a significant different between lean (mean = 4.98, SD = ±3.90) and non-lean (mean = 4.77, SD = ±3.68) sport. According to the sport type the 35% of lean sport athletes demonstrated low AMD, 34.1% moderate adherence and 30.9% a high degree. The non lean athletes demonstrated low AMD in 36.3%, moderate adherence 33% and high degree in 30.7%. The results of the mediation analysis indicated a significant mediation effect of intention in the relationship between TPB variables and MD. Based on the results of the study the type of sport does not play a role in the AMD, which, as in the general population, is low. Also validate the TPB and underscore the significance of targeting individuals' intentions to promote positive dietary behaviors.

Selected Determinants of Diet Health Quality among Female Athletes Practising Team Sports

This study's aim was an analysis regarding selected determinants of diet health quality in a group of elite Polish female team sport players. Relationships were assessed between age, sport experience, personal resources and personality traits with regard to the Big Five model and the pro-Health (pHDI-10) and non-Healthy (nHDI-14) Diet Indices. This study was conducted among 181 women (median age-25 years; sport experience-7 years) with the use of the Beliefs and Eating Habits Questionnaire (KomPAN), Generalised Self-Efficacy Scale (GSES), Multidimensional Health Locus of Control Scale (MHLC-B) and NEO-PI-R personality inventory. Statistical analysis was carried out via the Wilcoxon signed-rank test, Kruskal-Wallis's ANOVA, Spearman's rank correlation coefficient and forward stepwise regression at a significance level of α = 0.05. Multivariate regression analysis indicated that the value of the pro-Health Diet Index (pHDI-10) was positively explained by professional experience and extraversion, while negatively by openness to experiences (12% of the pHDI-10 variance). In turn, a higher value of the non-Healthy Diet Index (nHDI-14) was associated with the discipline of basketball (2% of the nHDI-14 variance). In summary, the demonstrated diet health quality was low and the predictive significance of competitive experience as well as type of discipline and selected personality traits was exhibited for diet quality among female team sport players.

Benfotiamine Supplementation Increases Thiamine in Muscle of Endurance-Trained Mice and Affects the Energy Metabolism

Background

Benfotiamine, a synthetic analog of thiamine, offers greater bioavailability compared to other thiamine salts and increases thiamine stores upon oral intake. Thiamine is essential for energy metabolism. This study aimed to evaluate the effects of oral benfotiamine supplementation on energy metabolism, particularly the Krebs cycle function, in the muscle of endurance-trained mice, and to assess its impact on endurance performance.

Methods

Twenty-five mice were randomly assigned to four groups: a standard diet with sedentary behavior (Sta-Sed), a benfotiamine-supplemented diet with sedentary behavior (Ben-Sed), a standard diet with swimming training (Sta-Tr), and a benfotiamine-supplemented diet with swimming training (Ben-Tr). The trained groups underwent five weekly swimming sessions for six weeks, followed by an exhaustive test. Thiamine and its esters were measured in erythrocytes and gastrocnemius muscle. Gene expression of pyruvate dehydrogenase (PDHa) and alpha-ketoglutarate dehydrogenase (OGDH), along with levels of pyruvic, lactic, and hydroxybutyric acids in muscle, was analyzed.

Results

The benfotiamine-supplemented groups had higher thiamine levels in erythrocytes and muscles compared to the standard-diet groups. No differences were observed in PDHa and OGDH gene expression. The Ben-Tr group exhibited increased muscle lactic acid levels and a higher lactic acid to pyruvic acid ratio compared to the sedentary groups. Hydroxybutyric acid levels were also elevated in the Ben-Tr group. No significant differences in exhaustive test duration were found between the groups.

Conclusion

Benfotiamine supplementation increases thiamine levels in erythrocytes and muscle but does not affect the gene expression of thiamine-dependent enzymes. Although it alters energy metabolism in trained muscle, it does not enhance endurance performance in mice.

Test-Retest Reliability of Running Economy and Metabolic and Cardiorespiratory Parameters During a Multistage Incremental Treadmill Test in Male Middle- and Long-Distance Runners

This study investigated the test-retest reliability of running economy (RE) and metabolic and cardiorespiratory parameters related to endurance running performance using a multistage incremental treadmill test. On two occasions separated by 21-28 days, 12 male middle- and long-distance runners ran at 10, 11, 12, 13, and 14 km/hr for 8 min each stage, immediately followed by a ramp test to volitional exhaustion. Carbohydrate (10% maltodextrin solution) was consumed before and during the test to provide ∼1 g/min of exercise. RE, minute ventilation (V˙E), oxygen consumption (V˙O2), carbon dioxide production (V˙CO2), respiratory exchange ratio (RER), heart rate (HR), ratings of perceived exertion (RPE), and blood glucose and lactate concentrations were recorded for each stage and at volitional exhaustion. Time-to-exhaustion (TTE) and peak oxygen consumption (V˙O2peak) during the ramp test were also recorded. Absolute reliability, calculated as the coefficient of variation (CV) between repeated measures, ranged from 2.3% to 3.1% for RE, whereas relative reliability, calculated as the intraclass correlation coefficient (ICC), ranged from .42 to .79. V˙E, V˙O2, V˙O2peak, V˙CO2, RER, and HR had a CV of 1.1%-4.3% across all stages. TTE and RPE had a CV of 7.2% and 2.3%-10.8%, respectively, while glucose and lactate had a CV of 4.0%-17.8%. All other parameters, except for blood glucose, were demonstrated to have good-to-excellent relative reliability assessed by ICC. Measures of RE, V˙O2peak, and TTE were reliable during this two-phase multistage incremental treadmill test in a cohort of trained and highly trained male middle- and long-distance runners.

Independent effects of volume and energy density manipulation on energy intake and appetite in healthy adults: A randomized, controlled, crossover study

Consuming enough energy to meet high energy demands can be challenging for military personnel wherein logistical constraints limit food availability. Increasing dietary energy density (ED) and/or volume density (VD) of rations may be countermeasures, but whether positive linear associations between ED and energy intake (EI) hold at moderate-to-high ED and VD is unclear. This study examined the effects of covertly increasing the ED and VD of moderate ED (≥1.6 kcal/g) foods on appetite and energy intake. Twenty healthy men completed four 2-day treatments in random order by consuming a standardized diet containing three experimental food items (EXP) engineered using leavening, physical compression and fat manipulation to be isovolumetric but lower (L) or higher (H) in ED and VD creating four treatments: LED/LVD, LED/HVD, HED/LVD, HED/HVD. Consumption of EXP was compulsory during two meals and a snack, but remaining intake was self-selected (SSF). Results failed to show any ED-by-VD interactions. During LVD, EI was lower for EXP (-417 kcal [95%CI: 432, -402], p < 0.01) and TOTAL (SSF + EXP) (-276 kcal [95%CI: 470, -83], p = 0.01) compared to HVD, while SSF EI did not differ (140 kcal [-51, 332], p = 0.15). During LED, EI for EXP (-291 kcal [95%CI: 306, -276], p < 0.01) was lower than HED, while SSF EI was higher than HED (203 kcal 95%CI: [12, 394], p = 0.04) and TOTAL EI did not differ (-88 kcal [-282, 105], p = 0.36). Thus, when a small isovolumetric portion of the diet was manipulated, increasing the VD of moderate ED foods failed to elicit compensatory reductions in ad libitum EI while increasing the ED of moderate ED foods did. Findings may support VD manipulation of moderate ED foods as a strategy to promote increased short-term EI in environments wherein logistical burden may limit food volume.

Nutrition for Children and Adolescents Who Practice Sport: A Narrative Review

At a developmental age, adequate physical activity is fundamental to overall health and well-being and preventing obesity. Moreover, establishing active behavior can help children and adolescents meet their growth and neurodevelopmental goals. Nutritional requirements vary according to intensity, frequency, and practiced physical activity or sport; therefore, pediatricians should give children and adolescents and their families adequate counseling, avoiding both nutrient deficiencies and excessive or inadequate supplement intake. The focus should be not only on sports performance but also on the child's well-being, growth, and neurodevelopment. Our narrative review aims to discuss the nutritional needs of children and adolescents who practice physical activity, non-competitive sports activity, and elite sports activity while also analyzing the role of food supplements and the risk of eating disorders within this category of subjects.

Evidence-based sports supplements: A redox analysis

Despite the overwhelming number of sports supplements on the market, only seven are currently recognized as effective. Biological functions are largely regulated through redox reactions, yet no comprehensive analysis of the redox properties of these supplements has been compiled. Here, we analyze the redox characteristics of these seven supplements: bicarbonates, beta-alanine, caffeine, creatine, nitrates, carbohydrates, and proteins. Our findings suggest that all sports supplements exhibit some degree of redox activity. However, the precise physiological implications of these redox properties remain unclear. Future research, employing unconventional perspectives and methodologies, will reveal new redox pixels of the exercise physiology and sports nutrition picture.

Assessment of Nutritional Practices of Mountain Runners before and during Competitions

Mountain running, distinct from traditional road running, involves natural trails with significant elevation changes. This study aims to analyze dietary and supplementation practices among advanced and elite Polish mountain runners. Conducted from May to October 2023, this study included 36 participants (13 women, 23 men) aged 21-43 years. A custom questionnaire assessed nutrition two days before and during a competition, focusing on macronutrient intake, hydration, and supplementation. Statistical analyses were performed to compare advanced and elite athletes. Participants consumed an average of 3164.14 kcal two days before and 3176.97 kcal the day before the competition. Carbohydrate intake averaged 7.69 g/kg two days before and 7.64 g/kg the day before the race, potentially insufficient for optimal glycogen stores. Protein intake was adequate, averaging 1.63 g/kg two days before and 1.73 g/kg the day before the race. Fluid intake averaged 2811.25 mL two days before and 2891.80 mL the day before the race. During races, carbohydrate intake averaged 58.56 g/h, with variations based on race duration. Most participants used isotonic drinks and water for hydration. Mountain runners generally adhere to proper nutrition guidelines, with adequate protein and fluid intake. However, their carbohydrate intake may be insufficient for longer races. Higher carbohydrate intake during exercise could provide additional benefits.

Development of a low-fructose carbohydrate gel for exercise application

This study aimed to develop a low-fructose (<3 g/serve) carbohydrate (CHO) gel for athletes. Various prototypes with 30 g CHO/serve and differing water content (12 %, 21 %, 32 %, 39 % w/v) were created and evaluated for sensory attributes. The final gel contained 62.1 ± 0.2 g CHO/100 g with 0.17 % w/w fructose. Endurance athletes (n = 20) underwent a feeding-challenge protocol, ingesting 30 g gel every 20 min during 2 h of running (60 %V ˙ O2max), followed by a 1 h self-paced distance test. Blood glucose increased significantly from baseline (4.0 ± 0.9 vs. 6.6 ± 0.6 mmol/L, p < 0.001) and remained elevated after the distance test (4.9 ± 0.7 mmol/L, p < 0.05). Breath hydrogen levels increased (5 ± 4 ppm, p < 0.05) without substantial CHO malabsorption detected. Gastrointestinal symptoms (GIS) increased during exercise but were mild. The low-fructose CHO gel demonstrated good tolerance, promoting glucose availability without severe GIS or CHO malabsorption.

Menstrual cycle disorders as an early symptom of energy deficiency among female physique athletes assessed using the Low Energy Availability in Females Questionnaire (LEAF-Q)

Physique competitions are weight-sensitive sports in which stage presentation, aesthetic appearance and posing ability of the athletes are judged rather than physical performance. The aim of this study was to assess low energy availability among female physique athletes by using the LEAF-Q. The study involved 104 females who were physique athletes. Monthly cycle disorders were reported in 58.65% of the women, that is periods stopped for three consecutive months or longer (amenorrhea). This situation occurred before the research was conducted in 43.27% of athletes and during the research in 15.38%. The physique athletes claimed that menstruation changes occurred when there was an increased exercise intensity, frequency or duration. Absence from training due to injury was reported by 27.88% of the women. The LEAF-Q identified 46.15% of the physique athletes as at risk (score ≥ 8) of low energy availability and the physiological consequences related to RED-S. Women who had menstrual cycle disorders were younger and did more training per week. Among women with menstrual disorders, cramps or stomach ache which cannot be related to menstruation occurred more frequently (p = 0.004). Absence from training or lack of participation in competition due to injuries occurred more frequently in the score ≥ 8 group (p = 0.024) thank the ≤ score 8 group. In the score ≥ 8 group menstruation changes, that is less bleeding or cessation of menstruation (p = 0.035), occurred more frequently when there was an increase in exercise intensity, frequency or duration (p = 0.002).

Total fermentable oligo-, di-, monosaccharides and polyols intake, carbohydrate malabsorption and gastrointestinal symptoms during a 56 km trail ultramarathon event

AIMS

To explore the relationship between nutritional intake, fermentable oligo-, di, monosaccharides and polyols, and carbohydrate malabsorption, with gastrointestinal symptoms during a 56 km trail ultramarathon event and identify differences in nutritional intake between runners with severe and non-severe gastrointestinal symptoms.

METHODS

Forty-four ultramarathoners recorded and self-reported dietary intake 3 days before, morning of, and during the ultramarathon with gastrointestinal symptoms obtained retrospectively and nutrient analysis via FoodWorks. Carbohydrate malabsorption was determined via breath hydrogen content pre- and post-race. Spearman's rank-order and Mann-Whitney U-tests were used to identify relationships and differences between groups.

RESULTS

Total fermentable oligo-, di, monosaccharides and polyols intake were not associated with gastrointestinal symptoms, but weak associations were observed for lower energy (rs = -0.302, p = 0.044) and fat intake (rs = -0.340, p = 0.024) 3 days before with upper gastrointestinal symptoms and higher caffeine intake 3 days before with overall gastrointestinal symptoms (rs = 0.314, p = 0.038). Total fermentable oligo-, di-, monosaccharides and polyols intake and breath hydrogen were not different between those with severe versus non-severe symptoms (p > 0.05). Although those with severe symptoms had higher caffeine (p = 0.032), and total polyols intake (p = 0.031) 3 days before, and higher % energy from fat (p = 0.043) and sorbitol intake (p = 0.026) during the race, and slower ultramarathon finish times (p = 0.042).

CONCLUSION

Total fermentable oligo-, di-, and monosaccharides intake and carbohydrate malabsorption were not associated with gastrointestinal symptoms. Additional research on the effect of fat, caffeine, and polyol intake on exercise-associated gastrointestinal symptoms is warranted and presents new nutritional areas for consideration when planning nutritional intake for ultramarathoners.

The impact of 48 h high carbohydrate diets with high and low FODMAP content on gastrointestinal status and symptoms in response to endurance exercise, and subsequent endurance performance

This study investigated the effects of a high carbohydrate diet, with varied fermentable oligo-, di-, and mono-saccharide and polyol (FODMAP) content, before endurance exercise on gastrointestinal integrity, motility, and symptoms; and subsequent exercise performance. Twelve endurance athletes were provided with a 48 h high carbohydrate (mean ± SD: 12.1 ± 1.8 g kg day-1) diet on two separate occasions, composed of high (54.8 ± 10.5 g day-1) and low FODMAP (3.0 ± 0.2 g day-1) content. Thereafter, participants completed a 2 h steady-state running exercise at 60% of V ˙ O 2 max (22.9 ± 1.2 °C, 46.4 ± 7.9% RH), followed by a 1 h distance performance test. Pre-exercise and every 20 min during steady-state exercise, 100 mL maltodextrin (10% w/v) solution was consumed. A 150 mL lactulose (20 g) solution was consumed 30 min into the distance performance test to determine orocecal transit time (OCTT) during exercise. Blood was collected pre- and post exercise to determine gastrointestinal integrity biomarkers (i.e., I-FABP, sCD14, and CRP). Breath hydrogen (H2) and gastrointestinal symptoms (GIS) were determined pre-exercise, every 15 min, during and throughout recovery. No differences in gastrointestinal integrity biomarkers, OCTT, or distance completed were observed between trials. Pre-exercise total-GIS (1.3 ± 2.9 vs. 4.3 ± 4.4), gut discomfort (9.9 ± 8.1 vs. 15.8 ± 9.0), and upper-GIS (2.8 ± 2.6 vs. 5.7 ± 4.8) during exercise were less severe on high carbohydrate low FODMAP (HC-LFOD) versus high carbohydrate high FODMAP (HC-HFOD) (p < 0.05). Gut discomfort (3.4 ± 4.4 vs. 0.2 ± 0.6) and total-GIS (4.9 ± 6.8 vs. 0.2 ± 0.6) were higher during recovery on HC-LFOD versus HC-HFOD (p < 0.05). The FODMAP content of a 48 h high carbohydrate diet does not impact gastrointestinal integrity or motility in response to endurance exercise. However, a high FODMAP content exacerbates GIS before and during exercise, but this does not impact performance outcomes.

Impact of a short-term nitrate and citrulline co-supplementation on sport performance in elite rowers: a randomized, double-blind, placebo-controlled crossover trial

PURPOSE

Citrulline (CIT) and beetroot extract (BR) have separately shown benefits in rowing performance-related outcomes. However, effects of combined supplementation remain to be elucidated. The main purpose of this research was to study the effects of 1 week of daily co-supplementation of 3.5 g BR (500 mg NO3-) plus 6 g CIT on aerobic performance, maximal strength, and high-intensity power and peak stroke in elite male rowers compared to a placebo and to a BR supplementation.

METHODS

20 elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1 week of supplementation in each group of study: Placebo group (PLAG); BR group (BRG); and BR + CIT group (BR-CITG). 3 main physical tests were performed: aerobic performance, Wingate test and CMJ jump, and metabolic biomarkers and physiological outcomes were collected.

RESULTS

The Wingate all-out test showed no between-condition differences in peak power, mean power, relative power, or fatigue index (P > 0.05), but clearance of lactate was better in BR-CITG (P < 0.05). In the performance test, peak power differed only between PLAG and BR-CITG (P = 0.036), while VO2peak and maximum heart rate remained similar. CMJ jumping test results showed no between-condition differences, and blood samples were consistent (P > 0.200).

CONCLUSION

Supplementation with 3.5 g of BR extract plus 6 g of CIT for 7 days improved lactate clearance after Wingate test and peak power in a performance test. No further improvements were found, suggesting longer period of supplementation might be needed to show greater benefits.

Carbohydrate beliefs and practices of ultra-endurance runners in Ireland for gastrointestinal symptom management

Purpose

This study aimed to investigate the carbohydrate beliefs and practices of ultra-endurance runners in Ireland to gain an understanding of their gastrointestinal symptom (GIS) management strategies.

Methodology

An adapted version of a previously developed and validated questionnaire was distributed online to ultra-endurance runners, recognized as those who completed a single bout of exercise lasting 4 or more hours. The questionnaire asked about carbohydrate awareness and sourcing, and dietary practices, particularly in relation to GIS management.

Results

A total of n = 68 individuals completed the adapted questionnaire. Of these, n = 1 was excluded due to their reporting of an ulcerative colitis diagnosis. The remaining participants included 46 men and 21 women. Personal previous experience was the main source directing participants' nutrition practices (n = 30), while only 3 participants quoted sourcing information from qualified professionals. Forty-two participants experienced GIS, usually equally around training and competition times. Many participants had not previously implemented any specific dietary or non-dietary strategies to alleviate exercise-induced GIS. Supplementing with nitrates (n = 9) and probiotics (n = 4) were the most common dietary practices to alleviate GIS, while other practices (n = 14) and portion control (n = 13) were the most reported non-dietary practices.

Discussion

Similar to previous studies, these findings suggest that GISs are prevalent in the ultra-endurance running community, occurring regardless of whether during training or an event. Similarly, this research highlights the vast range of GISs experienced by this population. However, the absence of both dietary and non-dietary-related practices used for GIS management alludes to a current deficit in the availability of nutrition information specific to this problem. Further research is required to understand the mechanisms behind ultra-endurance-associated GISs and its various management strategies as well as best practices for communicating these to the target audience to reduce individuals' risks of developing long-term, chronic health complications.

Nutrition for European Elite Fencers: A Practical Tool for Coaches and Athletes

The aim of this narrative review is to create a comprehensive, innovative, and pragmatic resource to guide elite fencers and coaches in making strategic nutritional choices to enhance performance and facilitate recovery. The literature review identified only 12 articles specifically addressing the topic of nutrition for fencers. Thus, the recommendations provided in this review derive also from articles dealing with similar sports, such as martial arts, and from investigations with European elite fencers and their coaches. For elite fencers, it is suggested to consume daily 7-11 g/kg of body weight (BW) of carbohydrates and 1.5-2 g/kg of BW of proteins and allocate 25% to 30% of the total energy intake to essential fats, with a specific focus on omega-3 fatty acids. The timing of meals, ideally within one hour after exertion, plays a pivotal role in restoring glycogen reserves and preventing injuries. The intake of leucine, creatine, omega-3, collagen, and vitamins C and D is proposed as a strategy for injury recovery. It is worth acknowledging that even when personalized plans are provided, implementation can be challenging, especially during competitions and training camps.

Harmony in Motion: Unraveling the Nexus of Sports, Plant-Based Nutrition, and Antioxidants for Peak Performance

The intricate interplay between plant-based nutrition, antioxidants, and their impact on athletic performance forms the cornerstone of this comprehensive review. Emphasizing the pivotal importance of dietary choices in the realm of sports, this paper sets the stage for an in-depth exploration of how stress and physical performance are interconnected through the lens of nutrition. The increasing interest among athletes in plant-based diets presents an opportunity with benefits for health, performance, and recovery. It is essential to investigate the connection between sports, plants, and antioxidants. Highlighting the impact of nutrition on recovery and well-being, this review emphasizes how antioxidants can help mitigate oxidative stress. Furthermore, it discusses the growing popularity of plant-based diets among athletes. It elaborates on the importance of antioxidants in combating radicals addressing stress levels while promoting cellular health. By identifying rich foods, it emphasizes the role of a balanced diet in ensuring sufficient intake of these beneficial compounds. Examining stress within the context of sports activities, this review provides insights into its mechanisms and its impact on athletic performance as well as recovery processes. This study explores the impact of plant-based diets on athletes including their types, potential advantages and challenges. It also addresses the drawbacks of relying on plant-based diets, concerns related to antioxidant supplementation and identifies areas where further research is needed. Furthermore, the review suggests directions for research and potential innovations in sports nutrition. Ultimately it brings together the aspects of sports, plant-based nutrition, and antioxidants to provide a perspective for athletes, researchers and practitioners. By consolidating existing knowledge, it offers insights that can pave the way for advancements in the ever-evolving field of sports nutrition.

Use of dietary supplements by children and adolescents

OBJECTIVES

Narrative review evaluating the use of dietary supplements by children and adolescents.

DATA SOURCE

The terms "dietary supplements", "children" and "adolescents" were used in combination in the PubMed, MEDLINE, and SciELO databases, between 2000 and 2023, evaluating studies in humans, published in Portuguese, English, French and Spanish.

DATA SYNTHESIS

The use of dietary supplements by children and adolescents has increased in recent decades. The most commonly used supplements are vitamins, minerals, trace elements, proteins, amino acids, melatonin, fatty acids, probiotics and energy drinks.

CONCLUSION

Despite having specific indications, most of the time they are not prescribed by a healthcare professional. The reasons for use are varied. In children, the main reasons are protection against infections, stimulating growth, and poor food intake, with multivitamins and minerals being the most commonly used supplements. In adolescents, they are used to improve athletic performance and attain the "ideal body", with proteins and amino acids being the most often used nutrients. As they are not regulated by health agencies and are sold without a prescription, their unsupervised use can lead to inadequate doses, with inefficiency or overdose risk. As for compounding formulations, or when available in preparations with multiple nutrients, the chance of errors increases. It is essential that pediatricians advise parents and patients about the indications, risks and benefits, prescribing them when necessary.

Functional nutrition for the health of exercising individuals and elite sportspersons

INTRODUCTION

Elite sportspersons who are involved in high-intensity physical sports indulge in severe training and competition schedules, which exposes them to high levels of inflammatory and oxidative stress, hence it may hamper their health sometimes. Disturbance in the health of sportspersons also induces compromised performances.

THE PREMISE FOR FUNCTIONAL NUTRITION

Functional nutrition is essential for elite sportspersons training for securing both rest and recovery to have proper health and anticipated performance. Apart from serving the energy needs of the sportspersons, the nutrition strategies should provide them with certain metabolic advantages, which provide greater health and immunity, to ensure proper training and competition. The diet of the sportspersons needs to contain appropriate anti-inflammatory and antioxidative nutrients, to ensure to reduction and control of the physiological stress of tissues during high-intensity physical sports, especially during marathon running. Preserving anabolic valence among sportspersons for muscle myokine optimization is an essential aspect of sports nutrition, which secures health and provides excellent performance potential. Preservation and optimization of gut microbiome among sportspersons enhance immune health and performance, through proper gut integrity and enhanced metabolic cascades. As the genes are to be properly expressed for excellent manifestation in protein synthesis and other metabolic signaling, achieving genetic valance through proper nutrition ensures the health of the sportspersons.

CONCLUSION

Functional nutrition seems a very necessary and potent factor in the training and competition aspects of elite sportspersons since nutrition not only provides recovery but also ensures proper health for elite sportspersons.

Measuring the Success of Global Sports Governance: A Deep Trust Network Model Approach

With the development of the economy and the improvement of living standards, people's needs have gradually changed, and sports has received increasing attention. At the same time, due to the significant efforts of all countries in sports, sports governance has also attracted considerable attention from scholars. However, the evaluation of global sports governance has rarely been discussed. This paper analyzes the principles for selecting indicators of global sports governance and develops a global sports governance evaluation indicator system consisting of 3 first-level indicators, 6 s-level indicators, and 14 third-level indicators. Additionally, this paper conducted an empirical study of the indicator system using the deep trust network model, and the results showed that the research on the evaluation index system of global sports governance based on the deep trust network model is feasible. Compared with the actual scores, the evaluation gaps for sports facility satisfaction, sports information satisfaction, and sports activity satisfaction were only 0.05, 0.09, and 0.05, respectively. Overall, this method is more accurate in analyzing the evaluation index system of global sports governance and can more directly and objectively reflect the shortcomings of current global sports governance, providing specific analysis of particular problems. The paper suggests that current global sports governance should focus on the coverage of sports facilities, attention to mass sports, satisfaction of sports activities, and promote in-depth development through both hard and soft governance measures.

Physical Exercise After Solid Organ Transplantation: A Cautionary Tale

An increasing body of randomized controlled trials suggests the safety of engaging in moderate to vigorous intensity exercise training following solid organ transplantation. Fueled by emerging sport events designed for transplant recipients and the ever-growing body of research highlighting the diverse health benefits of physical activity, transplant recipients are now increasingly participating in strenuous and occasionally competitive physical endeavors that largely surpass those evaluated in controlled research settings. This viewpoint article adopts a cautionary stance to counterbalance the prevalent one-sided optimistic perspective regarding posttransplant physical activity. While discussing methodological limitations, we explore plausible adverse impacts on the cardiovascular, immunological, and musculoskeletal systems. We also examine the physiological consequences of exercising in the heat, at high altitude, and in areas with high air pollution. Risks associated with employing performance-enhancing strategies and the conceivable psychological implications regarding physical activity as a tribute to the 'gift of life' are discussed. With a deliberate focus on the potential adverse outcomes of strenuous posttransplant physical activity, this viewpoint aims to restore a balanced dialogue on our comprehension of both beneficial and potentially detrimental outcomes of physical activity that ultimately underscores the imperative of well-informed decision-making and tailored exercise regimens in the realm of posttransplant care.

What if gastrointestinal complications in endurance athletes were gut injuries in response to a high consumption of ultra-processed foods? Please take care of your bugs if you want to improve endurance performance: a narrative review

To improve performance and recovery faster, athletes are advised to eat more often than usual and consume higher doses of simple carbohydrates, during and after exercise. Sports energetic supplements contain food additives, such as artificial sweeteners, emulsifiers, acidity regulators, preservatives, and salts, which could be harmful to the gut microbiota and impair the intestinal barrier function. The intestinal barrier plays a critical function in bidirectionally regulation of the selective transfer of nutrients, water, and electrolytes, while preventing at the same time, the entrance of harmful substances (selective permeability). The gut microbiota helps to the host to regulate intestinal homeostasis through metabolic, protective, and immune functions. Globally, the gut health is essential to maintain systemic homeostasis in athletes, and to ensure proper digestion, metabolization, and substrate absorption. Gastrointestinal complaints are an important cause of underperformance and dropout during endurance events. These complications are directly related to the loss of gut equilibrium, mainly linked to microbiota dysbiosis and leaky gut. In summary, athletes must be cautious with the elevated intake of ultra-processed foods and specifically those contained on sports nutrition supplements. This review points out the specific nutritional interventions that should be implemented and/or discontinued depending on individual gut functionality.

Nutrition knowledge, weight loss practices, and supplement use in senior competition climbers

Introduction

Sport climbing has gained increased scientific attention, including studies investigating the dietary habits and nutritional requirements of climbers; however, significant gaps in the literature remain. An assessment of nutritional knowledge, weight loss for competition, and supplement use has not been previously reported in senior competition climbing athletes.

Methods

Fifty climbers (26 male, 24 female; BMI 21.6 ± 1.9; 23.7 ± 5.2 years) participated in the study. Participants answered a 72-item questionnaire, comprised of demographic data and three main sections to assess general and sports nutrition knowledge, weight loss strategies, and supplement use.

Results

The mean nutrition knowledge score was 'average', with considerable individual variation (53.5 ± 11.1 %). There were no significant sex differences in the general (GNK) or sport (SNK) nutrition knowledge scores, or effect of age. Significantly higher knowledge was demonstrated by national vs. international athletes for the GNK scores (11.09 ± 1.58 vs. 9.58 ± 1.75; p = 0.028). Participants scored well in questions concerning protein, carbohydrates, alcohol, and supplements, and conversely, performed poorly in hydration and micronutrient related questions. Less than one-fifth of respondents had access to a dietitian. Forty-six percent of males and 38% of female climbers reported intentional weight loss for competition on at least one occasion. Of those, ~76% reported utilizing concerning practices, including methods that conform with disordered eating and/or eating disorders, dehydration, vomiting, and misuse of laxatives. Approximately 65% of athletes reported using at least one nutritional supplement in the previous 6 months, with 44% reporting multiple supplement use. There was no significant difference in supplement use between sexes or competition level.

Discussion

Due to the established importance of nutritional intake on athlete health and performance, educational support should be employed to improve knowledge in climbers and address shortcomings. Moreover, intentional weight loss for climbing competition is common, with most athletes achieving ~3-8% body weight loss over ≥2 weeks. It is crucial that professionals working with competitive climbers are vigilant in identifying athletes at risk of concerning weight management and establish referral pathways to the appropriate specialist services. High quality intervention trials to assess the efficacy of ergogenic aids in climbing remains inadequate.

Energy and Macronutrient Intakes in Young Athletes: A Systematic Review and Meta-analysis

The aim of this study was to conduct a systematic review and meta-analysis of differences in energy and macronutrient intakes between young athletes and non-athletes, considering age, gender and sport characteristics. The study included original research articles that compared energy and macronutrient intakes of 8 to 18-year-old athletes to non-athletes. Mean difference (MD) meta-analyses were performed to quantify energy and macronutrient intake differences between athletes and non-athletes. Eighteen observational studies were included. Results revealed that the energy and carbohydrate consumption of athletes was higher than that of non-athletes (MD=4.65kcal/kg/d, p<0.01 and MD=1.65% of total energy intake, p<0.01, respectively). Subgroup analyses revealed a significant effect of total training time on the observed mean differences between athletes and non-athletes. As practice time increased, the differences between athletes and non-athletes increased for carbohydrate and decreased for protein. Sport type analysis revealed a higher protein intake by mixed sport athletes compared to endurance and power sports. Analyses also indicated an age effect: the older the athletes, the smaller the differences between athletes and non-athletes for energy intake. However, the methods used to match groups and estimate dietary intakes forced us to moderate the results. More rigorous research methods are needed to define the dietary intakes of athletes and non-athletes.

Dietary habits in adolescent male and female handball players: the Swedish Handball Cohort

Objectives

This cross-sectional study aimed to describe dietary habits in Swedish adolescent handball players and differences with respect to sex and school grade.

Methods

Participants in the Swedish Handball Cohort answered a web-survey assessing adherence to sports nutrition recommendations for meal frequency and meal timing, and the Nordic Nutrition Recommendations (NNR) for fruits/vegetables and fish/seafood, food exclusions and use of dietary supplements. Differences with respect to sex and school grade were estimated with generalised linear models, generating prevalence ratios (PR) with 95% CIs.

Results

A total of 1040 participants (16.6±0.9 years, 51% males) were included. Overall, 70% and 90%, respectively, met recommendations for meal frequency and meal timing, whereas adherence to recommended carbohydrate intake during training/game was met by 17%. Adherence to the NNR for fruits/vegetables and fish/seafood was met by 16% and 37%, respectively. Twenty-eight per cent reported using dietary supplements. Females reported lower frequency of meals, especially morning snacks (-0.6 days/week (95% CI -0.3 to -0.9)) and evening snacks (-0.8 days/week (95% CI -0.5 to -1.1)), higher prevalence of exclusions due to intolerances (PR 1.66 (95% CI 1.31 to 2.01)) and other reasons (PR 1.36 (95% CI 1.08 to 1.64)), higher adherence to the NNR for fruits/vegetables (PR 2.30 (95% CI 1.98 to 2.62)) and use of micronutrient supplements (PR 1.72 (95% CI 1.43 to 2.00)) compared with males. Only small differences were observed between school grades.

Conclusions

Swedish adolescent handball players' dietary habits are fairly in accordance with sports nutrition recommendations but not the NNR. Females appear to display more restrictive habits than males.

Sports Nutrition Knowledge Questionnaires Developed for the Athletic Population: a Systematic Review

PURPOSE OF REVIEW

Sports nutrition (SN) is pivotal in aiding athletes to reach peak performance, minimize sport-related injuries, enhance career longevity, and improve general health. An accurate assessment of athletes' sports nutrition knowledge (SNK) is required to design targeted nutrition education programs aimed at enhancing both nutritional knowledge and dietary practices. This review systematically evaluates studies that use questionnaires to assess the SNK of athletes engaged in athletics.

RECENT FINDINGS

The literature search was conducted in PubMed®, Web of Science®, and Scopus®, and 375 potentially relevant articles were identified. The total number of articles included in the present review is 11, with eight studies involving only athletic disciplines and three involving athletics and other sports. The majority (n = 8) of the questionnaires included general and SN aspects, with SN covering endurance athletes' knowledge of competition carbohydrate guidelines, gastrointestinal symptoms associated with exercise, and ultra-endurance athletes' sodium beliefs and practices. Questionnaires were either delivered online (n = 7) or self-administered in hard copy (n = 1). The three major strategies identified for developing questionnaires were based on previous literature and recent SN guidelines (n = 6), consultation with a panel of experts (n = 7), and the use of a previously developed sports nutrition knowledge questionnaires (SNKQ) (n = 4), with more than one approach used in five studies. Similarly, up to three validation approaches were used, including content, face, and construct validity. Seven studies used a test-retest procedure to ensure external reliability, and eight used Cronbach's alpha or kappa coefficient to assess internal consistency. Endurance and ultra-endurance athletes are the populations of interest for the majority of questionnaires developed for athletics, with most questionnaires incorporating general and SNK topics.

The Physiological Requirements of and Nutritional Recommendations for Equestrian Riders

Equestrian sport is under-researched within the sport science literature, creating a possible knowledge vacuum for athletes and support personnel wishing to train and perform in an evidence-based manner. This review aims to synthesise available evidence from equitation, sport, and veterinary sciences to describe the pertinent rider physiology of equestrian disciplines. Estimates of energy expenditure and the contribution of underpinning energy systems to equestrian performance are used to provide nutrition and hydration recommendations for competition and training in equestrian disciplines. Relative energy deficiency and disordered eating are also considered. The practical challenges of the equestrian environment, including competitive, personal, and professional factors, injury and concussion, and female participation, are discussed to better highlight novelty within equestrian disciplines compared to more commonly studied sports. The evidence and recommendations are supported by example scenarios, and future research directions are outlined.

Evaluation of Validity and Reliability of a German General and Sports Nutrition Knowledge Questionnaire for Athletes and Coaches (GSNKQ-AC)

Despite the availability of nutritional recommendations, studies have reported inadequate nutrition in athletes. The existing literature highlights the importance of the nutritional knowledge of both athletes and coaches in influencing athletes' food choices and behavior, as well as its direct and indirect impact on athletes' performance and health. To adequately assess nutritional knowledge, monitoring via valid and reliable questionnaires is required. As no questionnaire tailored to German-speaking athletes and coaches exists, this study aimed at developing a new General and Sports Nutritional Knowledge Questionnaire for Athletes and Coaches (GSNKQ-AC). The development followed a literature-based, ten-step validation approach. The initial questionnaire (63 items) was revised and reduced to 29 items in the final version after conducting construct verification in the target group (n = 84 athletes and coaches), evaluating content validity by a panel of nutrition experts (n = 8), verifying face validity by think-out-loud interviews in the target group (n = 7), and conducting classical test theory for item reduction analysis (n = 53). For the final GSNKQ-AC, internal consistency, calculated as Cronbach's alpha, was 0.87. Students with a focus on sports nutrition (n = 31) scored significantly higher than athletes and coaches (n = 53), revealing good construct validity (77% vs. 62%, p < 0.001). Test-retest reliability (n = 42, matched pairs) showed a Spearman's correlation coefficient of r = 0.61 (p < 0.01). The brief GSNKQ-AC can be used for status quo or longitudinal assessment of nutritional knowledge among athletes and coaches to reveal gaps and ensure purposeful planning of educational interventions.

Exploring the Nutrition Strategies Employed by Ultra-Endurance Athletes to Alleviate Exercise-Induced Gastrointestinal Symptoms-A Systematic Review

(1) Background: Participation in ultra-endurance sports, particularly ultra-running, has increased over the previous three decades. These are accompanied by high energetic demands, which may be further exacerbated by extreme environmental conditions. Preparation is long-term, comprising of sufficient exercise management, supportive dietary habits, and nutritional intakes for optimal adaptations. Gastrointestinal symptoms are often cited as causing underperformance and incompletion of events. Though the majority do not pose serious long-term health risks, they may still arise. It has been suggested that the nutritional interventions employed by such athletes prior to, during, and after exercise have the potential to alter symptom incidence, severity, and duration. A summary of such interventions does not yet exist, making it difficult for relevant personnel to develop recommendations that simultaneously improve athletic performance by attenuating gastrointestinal symptoms. The aim of this research is to systematically review the literature investigating the effects of a nutrition intervention on ultra-endurance athletes exercise-induced gastrointestinal symptom incidence, severity, or duration. (2) Methods: A systematic review of the literature was conducted (PubMed, CINAHL, Web of Science, and Sports Discus) in January 2023 to investigate the effects of various nutrition interventions on ultra-endurance athletes' (regardless of irritable bowel syndrome diagnosis) exercise-induced gastrointestinal symptoms. Variations of key words such as "ultra-endurance", "gastrointestinal", and "nutrition" were searched. The risk of bias in each paper was assessed using the ADA quality criteria checklist. (3) Results: Of the seven eligible studies, one was a single field-based case study, while the majority employed a crossover intervention design. A total of n = 105 participants (n = 50 male; n = 55 female) were included in this review. Practicing a diet low in short-chain, poorly absorbed carbohydrates, known as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), as well as employing repetitive gut challenges of carbohydrates, remain the most promising of strategies for exercise-induced gastrointestinal symptom management. (4) Conclusion: Avoiding high-FODMAP foods and practicing repetitive gut challenges are promising methods to manage gastrointestinal symptoms. However, sample sizes are often small and lack supportive power calculations.

Authentication of protein, fat, carbohydrates, and total energy in commercialized high protein sports foods with their labeling data

The popularity of high-protein sports food items among athletes and the bodybuilding community has risen dramatically. This study aimed to authenticate the reported per serving food label content of protein, fat, carbohydrate, and total energy in commercially available high-protein sports foods available in Egyptian markets. A cross-sectional study was performed on a total of forty-five samples of nine products that included protein bars, cookies, vegan bars, puffs, whey protein, protein drinks, peanut butter, pancake mix, and Greek yogurt. Protein and fat analysis were done according to Kheldahl and Folich methods, respectively, while carbohydrate was calculated by difference. Total energy was calculated according to their content. A significant (p < 0.001) difference was found between the laboratory-assessed content and the reported food label values in protein, carbohydrate, and energy. Protein sport food products had significantly lower protein content (11.6 ± 4.67) obtained from laboratory measurement than the label reported value (17.17 ± 7.22). The fat content in vegan protein was 149.3% higher than the label values (1.67 vs. 0.67 g/serving). The mean fat content per serving of 30 out of 45 samples was significantly higher than the food label values in the bar (37.8%), puffs (32.7%), vegan protein (149.3%), and protein drinks (28.6%). These differences may result in compromised performance and undesired fat gain, as opposed to a desired increase in muscle mass, which could compromise the desired impact of the consumed sports foods.

Continuous Glucose Monitoring (CGM) in Sports-A Comparison between a CGM Device and Lab-Based Glucose Analyser under Resting and Exercising Conditions in Athletes

The objective of this pilot study was to compare glucose concentrations in capillary blood (CB) samples analysed in a laboratory by a validated method and glucose concentrations measured in the interstitial fluid (ISF) by continuous glucose monitoring (CGM) under different physical activity levels in a postprandial state in healthy athletes without diabetes. As a physiological shift occurs between glucose concentration from the CB into the ISF, the applicability of CGM in sports, especially during exercise, as well as the comparability of CB and ISF data necessitate an in-depth assessment. Ten subjects (26 ± 4 years, 67 ± 11 kg bodyweight (BW), 11 ± 3 h) were included in the study. Within 14 days, they underwent six tests consisting of (a) two tests resting fasted (HC_Rest/Fast and LC_Rest/Fast), (b) two tests resting with intake of 1 g glucose/kg BW (HC_Rest/Glc and LC_Rest/Glc), (c) running for 60 min at moderate (ModExerc/Glc), and (d) high intensity after intake of 1 g glucose/kg BW (IntExerc/Glc). Data were collected in the morning, following a standardised dinner before test day. Sensor-based glucose concentrations were compared to those determined from capillary blood samples collected at the time of sensor-based analyses and subjected to laboratory glucose measurements. Pearson's r correlation coefficient was highest for Rest/Glc (0.92, p < 0.001) compared to Rest/Fast (0.45, p < 0.001), ModExerc/Glc (0.60, p < 0.001) and IntExerc/Glc (0.70, p < 0.001). Mean absolute relative deviation (MARD) and standard deviation (SD) was smallest for resting fasted and similar between all other conditions (Rest/Fast: 8 ± 6%, Rest/Glc: 17 ± 12%, ModExerc/Glc: 22 ± 24%, IntExerc/Glc: 18 ± 17%). However, Bland-Altman plot analysis showed a higher range between lower and upper limits of agreement (95% confidence interval) of paired data under exercising compared to resting conditions. Under resting fasted conditions, both methods produce similar outcomes. Under resting postprandial and exercising conditions, respectively, there are differences between both methods. Based on the results of this study, the application of CGM in healthy athletes is not recommended without concomitant nutritional or medical advice.

Development of an Instrument to Evaluate the Intake of Liquids, Food and Supplements in Endurance Competitions: Nutritional Intake Questionnaire for Endurance Competitions-NIQEC

BACKGROUND

In the last few years endurance sports have experienced a great increase in the number of competitions and participants. Dietary-nutritional planning is key for performing well during such competitions. To date, there is no questionnaire expressly developed to be able to analyze the consumption of liquids, foods, and supplements, as well as gastrointestinal problems in these events. This study describes the development of the Nutritional Intake Questionnaire for Endurance Competitions (NIQEC).

METHODS

The study was composed in the following phases: (1) Bibliographic search for the most important nutrients, (2) focus groups (17 dietitian-nutritionists and 15 experienced athletes) and generation of items, (3) Delphi surveys, and (4) cognitive interviews.

RESULTS

After an initial shaping of the questionnaire with the items that emerged in the focus groups, their relevance was evaluated by means of the Delphi survey, which showed more than 80% approval for most items. Finally, the cognitive interviews indicated that the questionnaire was simple and complete for its purpose. The final NIQEC (n = 50 items) was divided in 5 sections: Demographic data; sports data; consumption of liquids, food and supplements before, during, and after the competition; gastrointestinal complaints, and dietary-nutritional planning for the competition.

CONCLUSIONS

The NICEQ is a useful tool that allows collecting information from participants on sociodemographic factors and gastrointestinal complaints, and estimating the intake of liquid, food, and supplements, for endurance competitions.

The Effect of Gut-Training and Feeding-Challenge on Markers of Gastrointestinal Status in Response to Endurance Exercise: A Systematic Literature Review

BACKGROUND

Nutrition during exercise is vital in sustaining prolonged activity and enhancing athletic performance; however, exercise-induced gastrointestinal syndrome (EIGS) and exercise-associated gastrointestinal symptoms (Ex-GIS) are common issues among endurance athletes. Despite this, there has been no systematic assessment of existing trials that examine the impact of repetitive exposure of the gastrointestinal tract to nutrients before and/or during exercise on gastrointestinal integrity, function, and/or symptoms.

OBJECTIVE

This systematic literature review aimed to identify and synthesize research that has investigated the impact of 'gut-training' or 'feeding-challenge' before and/or during exercise on markers of gastrointestinal integrity, function, and symptoms.

METHODS

Five databases (Ovid MEDLINE, EMBASE, CINAHL Plus, Web of Science Core Collection, and SPORTDiscus) were searched for literature that focused on gut-training or feeding-challenge before and/or during exercise that included EIGS and Ex-GIS variables. Quality assessment was conducted in duplicate and independently using the Cochrane Collaboration's risk-of-bias (RoB 2) tool.

RESULTS

Overall, 304 studies were identified, and eight studies were included after screening. Gut-training or feeding-challenge interventions included provision of carbohydrates only (n = 7) in various forms (e.g., gels or liquid solutions) during cycling or running, or carbohydrate with protein (n = 1) during intermittent exercise, over a varied duration (4-28 days). Gut discomfort decreased by an average of 47% and 26% with a 2-week repetitive carbohydrate feeding protocol (n = 2) and through repeated fluid ingestion over five trials (n = 1), respectively. Repetitive carbohydrate feeding during exercise for 2 weeks resulted in the reduction of carbohydrate malabsorption by 45-54% (n = 2), but also led to no significant change (n = 1). The effect of gut-training and feeding-challenges on the incidence and severity of Ex-GIS were assessed using different tools (n = 6). Significant improvements in total, upper, and lower gastrointestinal symptoms were observed (n = 2), as well as unclear results (n = 4). No significant changes in gastric emptying rate (n = 2), or markers of intestinal injury and permeability were found (n = 3). Inconclusive results were found in studies that investigated plasma inflammatory cytokine concentration in response to exercise with increased carbohydrate feeding (n = 2).

CONCLUSIONS

Overall, gut-training or feeding-challenge around exercise may provide advantages in reducing gut discomfort, and potentially improve carbohydrate malabsorption and Ex-GIS, which may have exercise performance implications.

Training Behaviors and Periodization Outline of Omnivorous, Vegetarian, and Vegan Recreational Runners (Part A)-Results from the NURMI Study (Step 2)

Runners train for long-distance competitions based on underlying motivations, which may be similar to individual dietary motivations (e.g., well-being and performance). Fundamental training differences may arise in recreational runners following different diet types (omnivore, vegetarian, vegan) considering possible motive variations. Following a cross-sectional design, distance runners completed a survey (online), including a thorough assessment of training behaviors with generic training details and periodization specifics in three phases: 1. an intermediary and rebound stage, 2. a main preparatory stage, and 3. a main event stage (tapering or interim event level/s). Kruskal-Wallis and chi-squared tests were used in the statistical analysis. A total of 245 fit recreational runners following omnivore (n = 109), vegetarian (n = 45), and vegan diets (n = 91) were included. Significant differences in the initial running motivation were found across dietary subgroups (p = 0.033) as well as for current motivations (p = 0.038), with vegetarians being the least health motivated (27% and 9%, respectively). No differences in each of the specific periods were found between diet types across the outline (p > 0.05). The present evidence shows that there is a lack of fundamental training differences based on recreational runners following different generic types of diets. The results of the present investigation may be especially relevant for future studies on safety, sustainability, and performance-enhancing dietary practices among athletes.

Bridging the gap: Evidence-based practice guidelines for sports nutritionists

Evidence-based practice is a systematic approach to decision-making developed in the 1990s to help healthcare professionals identify and use the best available evidence to guide clinical practice and patient outcomes amid a plethora of information in often challenging, time-constrained circumstances. Today’s sports nutrition practitioners face similar challenges, as they must assess and judge the quality of evidence and its appropriateness to their athlete, in the often chaotic, time-pressed environment of professional sport. To this end, we present an adapted version of the evidence-based framework to support practitioners in navigating their way through the deluge of available information and guide their recommendations to athletes whilst also reflecting on their practice experience and skills as evidence-based practitioners, thus, helping to bridge the gap between science and practice in sport and exercise nutrition.

Effects of a 16-Week Digital Intervention on Sports Nutrition Knowledge and Behavior in Female Endurance Athletes with Risk of Relative Energy Deficiency in Sport (REDs)

Female endurance athletes are considered a high-risk group for developing Relative Energy Deficiency in Sport (REDs). Due to the lack of educational and behavioral intervention studies, targeting and evaluating the effects of the practical daily management of REDs, we developed the Food and nUtrition for Endurance athletes-a Learning (FUEL) program, consisting of 16 weekly online lectures and individual athlete-centered nutrition counseling every other week. We recruited female endurance athletes from Norway (n = 60), Sweden (n = 84), Ireland (n = 17), and Germany (n = 47). Fifty athletes with symptoms of REDs and with low risk of eating disorders, with no use of hormonal contraceptives and no chronic diseases, were allocated to either the FUEL intervention (n = 32) (FUEL) or a 16-week control period (n = 18) (CON). All but one completed FUEL, while 15 completed CON. We found strong evidence for improvements in sports nutrition knowledge, assessed via interviews, and moderate to strong evidence in the ratings concerning self-perceived sports nutrition knowledge in FUEL versus CON. Analyses of the seven-day prospective weighed food record and questions related to sports nutrition habits, suggested weak evidence for improvements in FUEL versus CON. The FUEL intervention improved sports nutrition knowledge and suggested weak evidence for improved sports nutrition behavior in female endurance athletes with symptoms of REDs.

Athletes' Opinions on Food Provision at European Athletics Championships: Implications for the Future

In competitive events, athletes' performances can be affected by their food choices. In addition, nutrition labels are essential to sustain informed decisions and to allow athletes to comply with their dietary planning. Knowing what influences athletes' food choices will help to improve the food provision in future championships. Therefore, we aimed to study the factors influencing athletes' choices, their knowledge on nutrition labels, and their opinion on the food service at two European Athletics Championships. Questionnaires were completed by 339 athletes (57% males, 19.6 ± 1.3 years) competing at the 2019 European Athletics Under 20 and Under 23 Championships. Factors that may impact performance (time of the day and nutrient composition) were rated as important and very important by a higher percentage of athletes (78% and 74%, respectively) compared to the presence of teammates (32%) and the coach (23%). Among the athletes who knew what nutrition labels are (49%), 72% would like to have additional nutritional information in future championships. Furthermore, our study revealed that for most athletes (72%), food temperature is important or very important for food choices. Overall, food provision had positive results, but further research is needed to help organizers better tailor food provision to athletes' needs.

Carbohydrate knowledge, beliefs, and intended practices, of endurance athletes who report exercise-associated gastrointestinal symptoms

This study aimed to explore carbohydrate (CHO) knowledge, beliefs, and intended practices of endurance athletes who experience exercise-associated gastrointestinal symptoms (Ex-GIS) compared to those without Ex-GIS. A validated online questionnaire was completed by endurance athletes (n = 201) participating in >60 min of exercise that present with Ex-GIS (n = 137) or without (n = 64). Descriptive statistics were used for parametric and non-parametric data with appropriate significance tests. Associations between categorical data were assessed by Chi-square analysis, and post-hoc Bonferroni tests were applied when significant. A content analysis of open-ended responses was grouped into themes, and quantitative statistics were applied. Participants included runners (n = 114, 57%), triathletes (n = 43, 21%) and non-running sports (n = 44, 21%) who participate in recreational competitive (n = 74, 37%), recreational non-competitive (n = 64, 32%), or competitive regional, national, or international levels (n = 63, 31%). Athletes correctly categorized CHO (x̄ = 92-95%) and non-CHO (x̄ = 88-90%) food and drink sources. On a Likert scale of 1 (strongly disagree) to 5 (strongly agree) athletes typically agree or strongly agree that consuming CHO around key training sessions and competitions enhances athletic performance [median = 4 (IQR, 4-5)], and they intend to consume more CHO around exercise [median = 3 (IQR, 2-3)]. No differences in beliefs and intentions were found among athletes with or without Ex-GIS. To enhance athletic performance, most endurance athletes intend to consume more CHO around exercise. Adequate knowledge of CHO-containing food sources was apparent; however, specific CHO ingestion practices remain to be verified.

Evaluation of Supplement Use in Sport Climbers at Different Climbing Levels

The lack of specific recommendations on the use of supplements for sport climbers may be the reason for their misuse by athletes of this discipline. This study aimed to evaluate choices of dietary supplementation, the reasons for taking them, and the source of information on supplementation among sport climbers at different levels. In addition, how climbers subjectively evaluated the impact of their diets in supporting selected aspects of climbing training was evaluated. We enrolled 110 regular sport climbers (40 women and 70 men) from Wroclaw, Poland, who completed a validated questionnaire, assessing their use of dietary supplements, attitudes towards the influence of diet on sports performance, and climbing level. Their anthropometric measurements were also collected. Participants regarded diet as an important element of sports performance. Sport climbers indicated the Internet to be the main source of information on supplements. Health maintenance and improvement of recovery were the most frequently chosen reasons for taking dietary supplements. The most common supplements were isolated protein, vitamin C, vitamin D, magnesium, and amino acid blends. However, participants rarely used supplements suggested as beneficial for sport climbing performance. Therefore, developing recommendations for supplementation in sport climbing and promoting this should be an elementary part of the preparation for climbing training.

Nutritional Practices and Body Composition of South African National-Level Spinal Cord-Injured Endurance Hand Cyclists

Nutritional practices and body composition of para-athletes can impact their health and athletic performance. There is a paucity of research on the nutritional practices, including dietary and supplement intake, body composition and bone health of spinal cord-injured (SCI) endurance hand cyclists. This study assessed the body composition and dietary and supplement intake of 12 national-level SCI endurance hand cyclists (age: 44.0 ± 9.3 years). Bone mineral density (BMD) was assessed in a sub-sample of participants (n = 4) using dual-energy x-ray absorptiometry (DXA). Estimated body fat percentage was healthy (18.4 ± 5.1%) and lumbar spine BMD for the sub-sample was adequate, however hip BMD was low (Z-score and/or T-scores < −2). Carbohydrate intake for male and female participants was below the recommended intake (3.8 (2.9−4.1) and 2.4 (2.0−2.7) g/kg BW, respectively). Overall protein intake was adequate, whilst fat intake was high for both males and females (39.7 (37.7−41.6) and 42.1 (39.0−45.3)% of total energy, respectively). The reported intakes for a few key micronutrients were also below the recommended dietary allowance (RDA) and/or adequate intake (AI) for males (vitamin D, calcium). The prevalence of supplement use before, during, and after training was 40%, 100%, and 60%, respectively. In conclusion, the hand cyclists could benefit from nutritional guidance to match their daily carbohydrate intake with exercise requirements and optimise their fat intake. Optimal vitamin D and calcium intake is also important especially in the light of poor bone health below the lesion level.

An exploratory study of the management strategies reported by endurance athletes with exercise-associated gastrointestinal symptoms

This exploratory study investigated endurance athletes self-reported exercise-associated gastrointestinal symptoms (Ex-GIS) and associated strategies to manage symptomology. Adult endurance athletes with a history of Ex-GIS (n = 137) participating in events ≥ 60 min completed an online validated questionnaire. Respondents included runners (55%, n = 75), triathletes (22%, n = 30), and non-running sports (23%, n = 32), participating at a recreationally competitive (37%, n = 51), recreationally non-competitive (32%, n = 44), and competitive regional/national/international (31%, n = 42) levels. Athletes identified when Ex-GIS developed most frequently either around training (AT), around competitions (AC), or equally around both training (ET) and competitions (EC). Athletes reported the severity of each symptom before, during, and after exercise. Athletes predominantly categorized Ex-GIS severity as mild (< 5/10) on a 0 (no symptoms) to 10 (extremely severe symptoms) visual analog symptomology scale. The Friedman test and post hoc analysis with Wilcoxon signed rank test was conducted with a Bonferroni correction applied to determine differences between repeated measures. The only severe symptom of significance was the urge to defecate during training in the ET group (Z = –0.536, p = 0.01). Ex-GIS incidence was significantly higher during training and competitions in all categories. A content review of self-reported strategies (n = 277) to reduce Ex-GIS indicated popular dietary strategies were dietary fiber reduction (15.2%, n = 42), dairy avoidance (5.8%, n = 16), and a low fermentable oligosaccharides, monosaccharides, and polyols (FODMAP) diet (5.4%, n = 15). In contrast, non-dietary strategies included the use of medications (4.7%, n = 13) and relaxation/meditation (4.0%, n = 11). On a Likert scale of 1–5, the most successful dietary strategies implemented were dietary fiber reduction (median = 4, IQR = 4, 5), low FODMAP diets (median = 4, IQR = 4, 5), dairy-free diets (median = 4, IQR = 4, 5), and increasing carbohydrates (median = 4, IQR = 3, 4). Accredited practicing dietitians were rated as the most important sources of information for Ex-GIS management (n = 29). Endurance athletes use a variety of strategies to manage their Ex-GIS, with dietary manipulation being the most common.

Prevalence of Dietary Supplement Use among Athletes Worldwide: A Scoping Review

Athletes represent a major part of dietary supplement users. This scoping review aims to explore the prevalence of dietary supplement use among athletes worldwide, most commonly used supplements, sources of information on dietary supplements and their reasons for use of these supplements. PubMed, CINAHL, MEDLINE, and PsycInfo were searched for original research articles. Studies were included if they involved athletes, identified the prevalence of dietary supplement use, and were published after 2017. A total of 26 articles were reviewed. Prevalence of dietary supplement use varied among articles, but sex-based differences related to the types of used dietary supplements existed. Generally, the findings were consistent in terms of reasons for use and sources of information. Unfortunately, the lack of homogeneity regarding the definition of dietary supplements, definition of use, reporting timeframes, and data collection methods complicates the attempt to compare the findings among studies.

Assessment of Exercise-Associated Gastrointestinal Perturbations in Research and Practical Settings: Methodological Concerns and Recommendations for Best Practice

Strenuous exercise is synonymous with disturbing gastrointestinal integrity and function, subsequently prompting systemic immune responses and exercise-associated gastrointestinal symptoms, a condition established as "exercise-induced gastrointestinal syndrome." When exercise stress and aligned exacerbation factors (i.e., extrinsic and intrinsic) are of substantial magnitude, these exercise-associated gastrointestinal perturbations can cause performance decrements and health implications of clinical significance. This potentially explains the exponential growth in exploratory, mechanistic, and interventional research in exercise gastroenterology to understand, accurately measure and interpret, and prevent or attenuate the performance debilitating and health consequences of exercise-induced gastrointestinal syndrome. Considering the recent advancement in exercise gastroenterology research, it has been highlighted that published literature in the area is consistently affected by substantial experimental limitations that may affect the accuracy of translating study outcomes into practical application/s and/or design of future research. This perspective methodological review attempts to highlight these concerns and provides guidance to improve the validity, reliability, and robustness of the next generation of exercise gastroenterology research. These methodological concerns include participant screening and description, exertional and exertional heat stress load, dietary control, hydration status, food and fluid provisions, circadian variation, biological sex differences, comprehensive assessment of established markers of exercise-induced gastrointestinal syndrome, validity of gastrointestinal symptoms assessment tool, and data reporting and presentation. Standardized experimental procedures are needed for the accurate interpretation of research findings, avoiding misinterpreted (e.g., pathological relevance of response magnitude) and overstated conclusions (e.g., clinical and practical relevance of intervention research outcomes), which will support more accurate translation into safe practice guidelines.

How Do Male Football Players Meet Dietary Recommendations? A Systematic Literature Review

The aim of this review was to determine whether male football players meet dietary recommendations according to a UEFA expert group statement and to identify priority areas for dietetic intervention, including training periodization and field position. A database search of PubMed, Web of Science, EBSCO and Scopus was performed. To be included within the final review, articles were required to provide a dietary intake assessment of professional and semi-professional football players. A total of 17 studies met the full eligibility criteria. Several studies showed insufficient energy and carbohydrate intake compared to the recommendations. A majority of athletes consume adequate protein and fat intakes compared to the recommendations. In addition, several studies showed the insufficient intake of vitamins and minerals. This systematic review showed that football players do not meet the nutritional recommendations according to the UEFA expert group statement. Future research should be focused on how to apply nutritional recommendations specific for athletes in accordance with training periodization and positions on the field.

Acute caffeine supplementation enhances several aspects of shot put performance in trained athletes

The aim of this investigation was to determine the effect of a moderate dose of caffeine (3 mg/kg/b.m.) on muscular power and strength and shot put performance in trained athletes. Methods. Thirteen shot putters (eight men and five women) participated in a double-blind, placebo-controlled, randomized experiment. In two different trials, participants ingested either 3 mg/kg/b.m. of caffeine or a placebo. Forty-five min after substance ingestion, athletes performed a handgrip dynamometry test, a countermovement jump (CMJ), a squat jump (SJ), and a maximum-velocity push-up. The athletes also performed three types of throws: a backwards throw, a standing shot put and a complete shot put. Results. In comparison with the placebo, caffeine ingestion increased CMJ height (32.25 ± 7.26 vs. 33.83 ± 7.72 cm, respectively; effect size (ES) = 0.82, p = 0.012; +5.0%;) and SJ height (29.93 ± 7.88 vs. 31.40 ± 7.16 cm; ES = 0.63, p = 0.042; +6.4%) and distance in the standing shot put (10.27 ± 1.77 m vs. 10.55 ± 1.94 m; ES = 0.87, p = 0.009; +2.6%). However, caffeine ingestion did not increase strength in the handgrip test, power in the ballistic push-up, or distance in the backwards throw (all p > 0.05). Shot put performance changed from 11.24 ± 2.54 to 11.35 ± . 2.57 m (ES = 0.33, p = 0.26; +1.0%), although the difference did not reach statistically significant differences. Caffeine ingestion did not increase the prevalence of side effects (nervousness, gastrointestinal problems, activeness, irritability, muscular pain, headache, and diuresis) in comparison with the placebo (p > 0.05). Conclusion. In summary, caffeine ingestion with a dose equivalent to 3 mg/kg/b.m. elicited moderate improvements in several aspects of physical performance in trained shot putters but with a small effect on distance in a complete shot put.

Effects of the ketogenic diet on performance and body composition in athletes and trained adults: a systematic review and Bayesian multivariate multilevel meta-analysis and meta-regression

This systematic review with meta-analysis aimed to determine the effects of the ketogenic diet (KD) against carbohydrate (CHO)-rich diets on physical performance and body composition in trained individuals. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and The Cochrane Library were searched. Randomized and non-randomized controlled trials in athletes/trained adults were included. Meta-analytic models were carried out using Bayesian multilevel models. Eighteen studies were included providing estimates on cyclic exercise modes and strength one-maximum repetition (1-RM) performances and for total, fat, and free-fat masses. There were more favorable effects for CHO-rich than KD on time-trial performance (mode [95% credible interval]; -3.3% [-8.5%, 1.7%]), 1-RM (-5.7% [-14.9%, 2.6%]), and free-fat mass (-0.8 [-3.4, 1.9] kg); effects were more favorable to KD on total (-2.4 [-6.2, 1.8] kg) and fat mass losses (-2.4 [-5.4, 0.2] kg). Likely modifying effects on cyclic performance were the subject's sex and VO2max, intervention and performance durations, and mode of exercise. The intervention duration and subjects' sex were likely to modify effects on total body mass. KD can be a useful strategy for total and fat body losses, but a small negative effect on free-fat mass was observed. KD was not suitable for enhancing strength 1-RM or high-intensity cyclic performances.

The Key Role of Nutritional Elements on Sport Rehabilitation and the Effects of Nutrients Intake

Adequate nutrition is of utmost importance for athletes, especially during rehabilitation after injury in order to achieve fast healing and return to sports. The aim of this narrative review is to define the proper nutritional elements for athletes to meet their needs and facilitate their fast return to sports after surgery or injury, as well as determine the effects of specific nutrients intake. Studies on antioxidants, which are substances that protect against free radicals, for the injured athlete are few and unclear, yet poly-phenols and especially flavonoids might improve healing and inflammation following an injury. Benefits of vitamin C or E on muscle damage are disputable in relevant studies, while optimal levels of vitamin D and calcium contribute to bone healing. Minerals are also essential for athletes. Other supplements suggested for muscle damage treatment and protein synthesis include leucine, creatine, and hydroxymethylbutyrate. Diets that include high-quality products, rich in micronutrients (like vitamins, minerals, etc.) bio-active compounds and other nutritional elements (like creatine) are suggested, while an individualized nutrition program prescribed by a trained dietitian is important. Further studies are needed to clarify the underlying mechanisms of these nutritional elements, especially regarding injury treatment.