International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update

Survey of nutritional intake status in college baseball players

BACKGROUND

Diet is closely related to exercise performance. To improve athletes' performance and manage their condition, it is important to get sufficient energy and various nutrients. Thus, it is necessary that athletes understand their nutritional intake status to improve performance and maintain health. This study aimed to explore the nutritional intake status of college baseball players using the Food Frequency Questionnaire (FFQ). Furthermore, the characteristics of their nutritional intake status with respect to athletic performance were evaluated. The result of this studyprovide an opportunity for many under-developed college athletes with irregular lifestyles to recognize and improve their nutritional problems.

METHODS

In October 2022, a questionnaire survey of 116 male members of a college baseball club was conducted. Of whom, 100 (94.3%) members responded to the survey and 92 (92.0%) provided valid responses. The survey items included basic characteristics such as college grade and type of living arrangement, and information on living conditions, e.g. whether the participant ate breakfast. Nutritional intake was evaluated using the FFQ. Players were divided into the first (regular players in official games), second (bench players in official games), third (players who may join the second or higher team in the future), and fourth teams (players who do not belong to the first to third teams); these categories were used as a marker of performance level. The Kruskal-Wallis test was used to analyze the association between the performance levels of baseball players and the intake of each nutrient and food group obtained by the FFQ. For items that showed a significant association, inter-group comparison was performed using the Dunn-Bonferroni method.

RESULTS

Carbohydrate intake was greater in the second team compared with the third and fourth teams; saturated and monounsaturated fatty acid intake was higher in the third team compared with the fourth team. Calcium, zinc, copper, manganese, insoluble dietary fiber, iodine, and molybdenum intake was higher in the second team compared with the fourth team. Intake of grains, sugar, dairy, and total energy was significantly higher in the second team compared with the fourth team. However, the protein intake ratio was significantly lower in the second team compared with the fourth team. Overall, energy deficiency and associated deficiencies in protein, fat, and carbohydrate were observed, in addition to dietary fiber and calcium deficiencies. The intake of several food groups appeared inadequate, such as potatoes, beans, vegetables, fruits, eggs, milk, and fats.

CONCLUSIONS

The study showed deficiencies in the amount of energy and nutrients such as protein, fat, and carbohydrate in college baseball players. Differences in the intake of carbohydrate, calcium, and insoluble dietary fiber among different performance levels were observed, with significantly higher intake of carbohydrate, calcium, and insoluble dietary fiber in the second team. Implementing organized and strategic remedial measures and athletes' identification of nutritional problems are vital to overcome nutritional and energy deficiencies. This study provides useful information for the development of strategies to support nutritional intake in college baseball players.

Diving Into the Health Problems of Competitive Divers: A Systematic Review of Injuries and Illnesses in Pre-elite and Elite Diving Athletes

CONTEXT

The Olympic sport of diving involves the competitive disciplines of 3 m springboard and 10 m platform. Although it is generally accepted that lumbar spine injuries are common in diving athletes, the existing literature of health problems in diving athletes remains scarce.

OBJECTIVE

To identify the incidence, prevalence, and type of health problems that occur in competitive diving athletes.

DATA SOURCES

Medline, EMBASE, SportsDiscus, PsycINFO, and Google Scholar.

STUDY SELECTION

Studies written in English investigating elite or pre-elite competitive diving (springboard, platform) injuries and/or illnesses were eligible. Two independent reviewers screened for inclusion by title, abstract, and full text in accordance with the eligibility criteria.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Data extraction was completed by 1 author using a structured form. A second author then independently reviewed and verified the extracted data, any discrepancies were resolved through consensus.

RESULTS

The search identified 2554 potential articles, with 28 studies meeting eligibility criteria. The surveillance setting of most studies was restricted to competition-based events, with the reported injury incidence proportion ranging from 2.1% to 22.2%. The reported injury incidence rate ranged from 1.9 to 15.5 per 1000 athlete-exposures. Injuries to the shoulder, lower back/lumbar spine, trunk, and wrist/hand were reported most frequently. The prevalence of low back pain was reported as high as 89% (lifetime), 43.1% (period), and 37.3% (point). The illness incidence proportion ranged from 0.0% to 22.2%, with respiratory and gastrointestinal illness reported most frequently.

CONCLUSION

Up to 1 in 5 diving athletes sustain an injury and/or illness during periods of competition. A reporting bias was observed, with most cohort studies limiting surveillance to short competition-based periods only. This limits the current understanding of the health problems experienced by diving athletes to competition periods only and requires expansion to whole-of-year surveillance.

Barriers and enablers encountered by elite athletes during preconception and pregnancy: a mixed-methods systematic review

OBJECTIVE

To synthesise the existing literature relating to barriers and enablers encountered by elite athletes during preconception and pregnancy for the purpose of identifying key recommendations and actionable steps to inform the development of pregnancy guidelines to support preconception and pregnancy in national sporting organisations.

DESIGN

Mixed-methods systematic review with thematic analysis.

DATA SOURCES

Four databases (Medline, SPORTDiscus, PsycINFO and CINAHL) were systematically searched to identify relevant studies, along with reference lists of included studies until 3 April 2023.

ELIGIBILITY CRITERIA

Peer-reviewed primary studies from any date, language and location which identify at least one barrier and/or enabler encountered by elite female athletes during preconception and/or pregnancy were included. Grey literature, books, conference papers and other reviews were excluded.

RESULTS

A total of 29 studies met the eligibility criteria for inclusion. The most common barriers identified were attitudes, perceptions and beliefs of the athlete and society, lack of support provided by sports organisations and lack of evidence-based information available. The most common enablers were specific strategies used by athletes (eg, modified training) to manage the demands of preconception and pregnancy, attitudes, perceptions and beliefs of the athlete, and support of family.

CONCLUSION

Key recommendations developed from the results are for sporting organisations to (1) develop clear, transparent and multifaceted policies to support preconception and pregnancy; (2) foster supportive environments which offer flexible training, social support and positive promotion of pregnant athletes and (3) provide clear, evidence-based education and information about preconception and pregnancy to athletes, coaches, support staff and organisational staff.

Pre-Participation Evaluation of Recreational and Competitive Athletes - A Systematic Review of Guidelines and Consensus Statements

BACKGROUND

Pre-participation evaluation (PPE) aims to support safe participation in sports. The goal of this systematic review was to aggregate evidence- and consensus-based recommendations for the PPE of recreational or competitive athletes as preparation for developing a German guideline on this subject.

METHODS

Five databases, including MEDLINE, were searched in August 2022, complemented by searches on the websites of relevant guideline organisations and specialty medical associations and citation screening. We included guidelines/consensus statements with recommendations for PPE of adult recreational athletes or competitive athletes of any age, excluding those with certain chronic illnesses. We extracted and synthesised data in a structured manner and appraised quality using selected domains of the AGREE-II tool.

RESULTS

From the 6611 records found, we included 35 documents. Overall, the quality of the included documents was low. Seven documents (20%) made recommendations on the entire PPE process, while the remainder focussed on cardiovascular screening (16/35, 45.7%) or other topics. We extracted 305 recommendations. Of these, 11.8% (36/305) applied to recreational athletes and 88.2% (269/305) applied to athletes in organised or competitive sports. A total of 12.8% (39/305) of recommendations were directly linked to evidence from primary studies.

CONCLUSION

Many recommendations exist for PPE, but only a few are evidence based. The lack of primary studies evaluating the effects of screening on health outcomes may have led to this lack of evidence-based guidelines and contributed to poor rigour in guideline development. Future guidelines/consensus statements require a more robust evidence base, and reporting should improve.

REGISTRATION

PROSPERO CRD42022355112.

Influence of Body Weight Measurement Frequency on the Bone Health of Female Athletes

Purpose: Athletes struggle with bone stress injuries despite the many risk factors reported in previous studies. However, the relationship between body weight measurement frequency and risk of stress fractures has yet to be investigated. Thus, the purpose of this study is to seek the link between body weight measurement frequency and the occurrence of stress fractures. Method: This cross-sectional study included female athletes who were requested to fill out an anonymous online survey regarding their personal background, including the history of amenorrhea and stress fractures. In addition, the frequency at which they measured their body weight and composition and whether they had to report the same to their coaches and seniors were asked. Results: A total of 172 collegiate female athletes for 28 different types of sports participated in this study. Among the included athletes, 35.7% had a history of amenorrhea, whereas 29.7% had a history of stress fractures. A total of 57.0% of the athletes answered that in their team, they measure their body weight on a regular basis, and 33.1% of the athletes answered that they reported the data to their coaches. Logistic regression analysis revealed that those who measured their body weight at least once a day had a higher risk of sustaining stress fractures than did those who measured their body weight less than once a day (OR = 2.36, 95% CI 1.06-5.27, p = .04). Conclusion: Body weight measurement frequency was associated with the risk of stress fractures in female collegiate athletes.

The barriers and facilitators of improving energy availability amongst females clinically diagnosed with Relative Energy Deficiency in Sport (REDs)

BACKGROUND

Relative Energy Deficiency in Sport (REDs) is a serious clinical condition. However, there is little research in athletes with a clinical diagnosis and limited evidence on the recovery of REDs.

METHODS

This is a cross-sectional retrospective study whereby 55 (25.62±6.33 years) female patients with a prior diagnosis of REDs by an experienced medical specialist participated in an online questionnaire designed to capture their experience of a sports dietitian consultation and subsequent implementation of a personalized energy availability (EA) plan.

RESULTS

A 31% increase (N.=4 vs. N.=16, P=0.002) in normal menstruation, a 22% reduction (N.=39 vs. N.=27, P=0.032) in gastrointestinal symptoms, and a 94% reduction (N.=16 to N.=1) in a very poor/poor appetite were reported following the consultation and plan implementation. Required energy intake (EI) was under-estimated by 93% of participants. Intake pre-exercise was implemented most frequently (69%, N.=38), and least likely to elicit feelings of stress and anxiety (69%, N.=38). Weight gain/shape change was the most frequently reported barrier to implementation (62%, N.=34). Eating to a planned regime (35%, N.=19) and following a timing of intake (33%, N.=18) gave the most confidence.

CONCLUSIONS

Providing an athlete with an education of their current and required EA, alongside an illustrated personalized EI plan structured around exercise, may provide the "lightbulb" moment needed to overcome the associated anxiety when increasing their EI when recovering from REDs.

Nutrition educational interventions for athletes related to low energy availability: A systematic review

Low energy availability (LEA) is a prevalent concern among athletes, often attributed to intentional or unintentional under-fueling behaviors. Nutritional and energy availability educational interventions are poised for successful LEA prevention, with a robust body of literature examining intervention effectiveness. Thus, this systematic review aimed to synthesize the available evidence on nutritional education interventions to address gaps in nutritional knowledge and combat LEA among athletes. Medical databases (MEDLINE, Web of Science) were systematically searched on July 11, 2023, and an updated search was conducted on July 26, 2024. Studies conducted among adult athletes who underwent nutritional education interventions with assessed effects on dietary knowledge, behaviors, and/or LEA outcomes were included. Study quality was assessed using the Physiotherapy Evidence Database (PEDro) scale by two blinded assessors. Intervention methodology and primary outcomes related to nutritional interventions were extracted by a single assessor. Twelve articles were included (mean PEDro score: 5). Interventions ranged from 1 to 20 sessions, and 10- to 120-minute durations. Most studies employed in-person educational sessions on fueling and macro- and micro-nutrient intake for athletic performance. Half of included studies included LEA education. Intervention approaches were largely heterogeneous, although most programs had favorable outcomes for nutrition knowledge and fueling behaviors. Nutrition interventions appear to be beneficial for athletes in the context of LEA, though current approaches are largely heterogenous. Future research should seek to develop a translational nutritional education plan for broad application in athletes designed to increase nutritional knowledge and combat LEA.

A formative investigation assessing menstrual health literacy in professional women's football

The aim of this study was to assess and compare menstrual health literacy in professional women's football. A three-section questionnaire was completed by professional players (n = 25), development players (n = 22) and staff (n = 19). The mean total knowledge score (out of 19) was lower for development players (5.4 ± 2.9) than professional players (7.8 ± 3.2) and staff (9.1 ± 4.8) (p < 0.001). No group achieved >50% correct answers. For each group, knowledge of the menstrual cycle (MC) was greater than knowledge of hormonal contraceptives (HC) (p < 0.001). Previous MC and HC education did not correspond to higher knowledge scores in professional players (p = 0.823) or development players (p = 0.274). In professional and development players, comfort of communication was influenced by the sex of whom they were communicating with (p < 0.001), with a preference for females. In conclusion, results from the present study suggest refined education strategies and new approaches are required for both players and staff to improve menstrual health literacy in professional women's football.

The health promoting sports coach: theoretical background and practical guidance

The sports club setting is a key context for health promotion, but it can also be associated with risky behaviours. Sports coaches play a crucial role in supporting the physical, mental and social health of sport participants but often lack the resources and support to do so. This paper proposes a guide to help coaches become health promoters by aligning their actions with the Health Promoting Sports Club model, which represents the setting-based approach applied to sports clubs. An embedded mixed-method study with a QUAL (qual) design was used, where 15 experts took part in 5 meetings and 299 coaches provided input through an online survey. Four steps were carried out: (1) defining the health-promoting sports coach and key action principles, (2) co-constructing progression stages using the settings-based approach, (3) identifying key actions for promoting health in different moments of coaching (i.e., before, during, and after training and competition, and outside of coaching), and (4) developing long-term intervention components. A definition of the health-promoting sports coach was produced, and eight key action principles have been identified, divided into three dimensions: connection with the system, adoption of a coaching philosophy, and focus on participants. Five stages of progression for integrating health promotion into coaching have been established, ranging from risk prevention to a global approach involving the entire sports system. Specific actions for each moment of coaching (before, during, and after training and competition, and outside of coaching) have been identified, such as monitoring the physical, mental, and social health of participants or plan the coaching session to ensure safety, inclusion, and well-being for all sports participants, staying open for last-minute changes. Finally, long-term intervention components to support the implementation of these actions in practice have been developed, based on what coaches are already doing, the skills they possess and the five stages of progression. This paper enables the development of a guide to help sports coaches promote health by identifying concrete actions and short- and long-term interventions, whilst making links with the health promoting sports club model. It broadens the scope of coaching by incorporating health principles, while emphasising the need to adapt to the environment and context of the club. This work calls for future research to test the effectiveness and feasibility of these approaches in various sporting environments.

Physiology and Pathophysiology of Marathon Running: A narrative Review

BACKGROUND

Marathon training and running have many beneficial effects on human health and physical fitness; however, they also pose risks. To date, no comprehensive review regarding both the benefits and risks of marathon running on different organ systems has been published.

MAIN BODY

The aim of this review was to provide a comprehensive review of the benefits and risks of marathon training and racing on different organ systems. A predefined search strategy including keywords (e.g., marathon, cardiovascular system, etc.) and free text search was used. Articles covering running regardless of sex, age, performance level, and event type (e.g., road races, mountain marathons) were considered, whereas articles examining only cycling, triathlon, stress-tests or other sports were excluded. In total, we found 1021 articles in PubMed, Scopus, and Google Scholar, of which 329 studies were included in this review. Overall, marathon training offers several benefits for different organ systems and reduces all-cause mortality. As such, it improves cardiovascular risk factors, leads to favorable cardiac adaptations, enhances lung function, and improves quality of life in chronic kidney disease patients. It also enhances gastrointestinal mobility and reduces the risk of specific tumors such as colorectal cancer and hepatocellular carcinoma. Marathon training enhances bone health and skeletal muscle metabolism. It further positively affects hematopoiesis and cytotoxic abilities of natural killer cells, and may act neuroprotective on a long-term basis. After a marathon, changes in biomarkers suggesting pathological events in certain organ systems such as cardiovascular, renal, gastrointestinal, liver, hematological, immune, musculoskeletal, central nervous, and endocrine systems can often be observed. Mostly, these changes are limited to 1-3 days post-race and usually normalize within a week. Moreover, marathon running poses the risk of serious adverse events such as sudden cardiac death or acute liver failure. Concerning lung function, a decrease after a marathon race was observed. Acute kidney injury, as well as electrolyte imbalances, are relatively common amongst marathon finishers. Many runners complain of gastrointestinal symptoms during or after long-distance running. Many runners suffer from running-related musculoskeletal injuries often impairing performance. A marathon is often accompanied by an acute inflammatory response with transient immunosuppression, making runners susceptible to infections. Also, hormonal alterations such as increased cortisol levels or decreased testosterone levels immediately after a race are observed. Disturbances in sleep patterns are commonly found in marathon runners leading up to or directly after the race.

CONCLUSION

All in all, marathon training is generally safe for human health and individual organ systems. Considering the high popularity of marathon running, these findings supply athletes, coaches, sports scientists, and sports medicine practitioners with practical applications. Further large-scale studies examining long-term effects on the cardiovascular, renal, and other system are needed.

Examination of the Clinical Utility of Eating Disorder and Disordered Eating Screening Tools in Young Athletes: A Scoping Review

Background and Purpose

Many screening tools are used to identify eating disorders (ED) and disordered eating (DE) in individuals. The purpose of this scoping review was to identify the most commonly used ED/DE screening tools for young male and female athletes.

Study Design

Scoping Review.

Methods

Following the Johanna Briggs Institute scoping review guidelines, PubMed, CINAHL Complete, PsycInfo, SPORTdiscus, and Web of Science Core Collection databases were searched using keywords related to eating disorder, disordered eating, athletes, and screening. Included articles were randomized controlled trials, cohort studies, or cross-sectional studies published in English between 2011-2023; included primarily non-aesthetic athletes aged 14-24 years; and utilized an ED/DE screening tool for diagnostic purposes. Articles were excluded if analysis of ED/DE was a secondary purpose or < 20 athletes participated. Tools utilized and demographic and outcomes data were extracted and qualitatively analyzed.

Results

Thirty articles were included. The Eating Attitudes Test-26 (EAT-26), the Sick, Control, One, Fat, Food (SCOFF) questionnaire, and the Eating Disorder Inventory (EDI) were most used among all included articles. Three articles examined only males and used a variety of tools. Five articles utilized a tool specifically designed for athletes: the Eating Disorder Screen for Athletes (EDSA), Brief Eating Disorder in Athletes Questionnaire (BEDA-Q) or the ATHLETE questionnaire.

Discussion

While the EAT-26 is most used for diagnosing ED/DE risk within young athletes, clinical utility of screening tools for male athletes is varied. Combinations of tools utilized for examining ED/DE risk in athletes are not agreed upon. Continued research is needed to assess the clinical utility of screening tools that identify ED/DE risk specifically in athletes. Tool adjustment or development for male athletes may be necessary.

Level of Evidence

2a.

Beyond knowledge: Unveiling the hidden link between body image and dietary intake in elite race walkers at risk of relative energy deficiency in sport

Background: Nutritional knowledge and body image concerns are key factors influencing dietary intake and health among athletes, particularly in lean-type sports. This study investigates these variables among elite race walkers from the United Kingdom and Ireland, a cohort selected for the prominence of race walking in their national sports programmes and unique cultural contexts. Aim: The study aims to assess the relationship between nutritional knowledge, body image, and dietary intake in elite race walkers, and explore the potential risk of relative energy deficiency in sport (RED-S). Methods: Eight elite race walkers (seven males, one female) were assessed using the Body Image Avoidance Questionnaire (BIAQ) and the Abridged Nutrition for Sport Knowledge Questionnaire. Dietary intake was evaluated through detailed food diaries and analysed against established nutritional guidelines. The Goldberg cut-off method was employed to identify dietary misreporters. Results: Despite moderate nutritional knowledge (58.93 ± 8.68%), athletes displayed suboptimal dietary habits with prevalent over-reporting. Carbohydrate intake was below recommended levels (5.4 ± 1.0 g/kg/day), while protein intake exceeded guidelines (2.0 g/kg/day). Body image dissatisfaction was common, particularly in the single female athlete, who scored highest on both nutritional knowledge and body image avoidance (BIAQ score: 62). The findings suggest a possible link between body image concerns and inappropriate dietary behaviours, increasing the risk of RED-S. Conclusion: While the study highlights the complex interplay between nutritional knowledge, body image dissatisfaction, and dietary intake, the small sample size (N = 8), particularly the inclusion of only one female athlete, limits the generalizability of the findings and introduces a potential bias in sex-specific interpretations. Future research should include larger, more diverse populations.

Nutritional Considerations in Exercise-Based Heat Acclimation: A Narrative Review

In addition to its established thermoregulatory and cardiovascular effects, heat stress provokes alterations in macronutrient metabolism, gastrointestinal integrity, and appetite. Inadequate energy, carbohydrate, and protein intake have been implicated in reduced exercise and heat tolerance. Classic exercise heat acclimation (HA) protocols employ low-to-moderate-intensity exercise for 5-14 days, while recent studies have evolved the practice by implementing high-intensity and task-specific exercise during HA, which potentially results in impaired post-HA physical performance despite adequate heat adaptations. While there is robust literature demonstrating the performance benefit of various nutritional interventions during intensive training and competition, most HA studies implement few nutritional controls. This review summarizes the relationships between heat stress, HA, and intense exercise in connection with substrate metabolism, gastrointestinal function, and the potential consequences of reduced energy availability. We discuss the potential influence of macronutrient manipulations on HA study outcomes and suggest best practices to implement nutritional controls.

Examination of Energy Needs and Low Energy Availability Among Historically Black College and University Female Student-Athletes

Low energy availability (LEA) is common among female student-athletes and contributes to reduced bone mineral density and hormonal dysfunction. However, limited research exists on student-athletes of color, making it difficult to generalize results across populations, particularly Historically Black Colleges and Universities (HBCUs) student-athletes.

OBJECTIVES

This study examined the energy needs and LEA prevalence, with or without eating disorder (ED) risk, among HBCU female student-athletes.

METHODS

Twenty-seven female student-athletes (age = 19 ± 1 year; height = 166.9 ± 7.6 cm; weight = 68.8 ± 11.3 kg) completed baseline measures, including the Eating Disorder Inventory-3 (EDI-3), EDI-3 symptom checklist (EDI-SC), anthropometric measures, and resting metabolic rate (RMR). Participants maintained a dietary log to measure energy intake and wore a heart rate monitor to estimate exercise energy expenditures for 7 days. LEA was defined as <30 kcal/kg of fat-free mass (FFM)/day.

RESULTS

The mean energy availability (15.9 ± 10.1 kcal/kg FFM/day) indicated 92.6% of participants (n = 25) displayed LEA; of those, 60% (n = 15) had LEA with ED risk. ED risk was identified in 59.3% of student-athletes (n = 13; EDI-3: n = 2; SC: n = 3; Both: n = 11). Interestingly, of the two student-athletes without LEA, one was identified at risk for EDs using both the EDI-3 and SC.

CONCLUSIONS

HBCU female student-athletes face high risks of LEA and EDs, with most showing signs of both. This underscores the need for culturally sensitive interventions to improve EA and support mental health in this underserved group. Clinicians should focus on nutrition education and early ED identification to enhance long-term health and athletic performance.

How Does Physical Activity Modulate Hormone Responses?

Physical activity highly impacts the neuroendocrine system and hormonal secretion. Numerous variables, both those related to the individual, including genetics, age, sex, biological rhythms, nutritional status, level of training, intake of drugs or supplements, and previous or current pathologies, and those related to the physical activity in terms of type, intensity, and duration of exercise, or environmental conditions can shape the hormonal response to physical exercise. The aim of this review is to provide an overview of the effects of physical exercise on hormonal levels in the human body, focusing on changes in concentrations of hormones such as cortisol, testosterone, and insulin in response to different types and intensities of physical activity. Regular monitoring of hormonal responses in athletes could be a potential tool to design individual training programs and prevent overtraining syndrome.

Women in space: A review of known physiological adaptations and health perspectives

Exposure to the spaceflight environment causes adaptations in most human physiological systems, many of which are thought to affect women differently from men. Since only 11.5% of astronauts worldwide have been female, these issues are largely understudied. The physiological nuances affecting the female body in the spaceflight environment remain inadequately defined since the last thorough published review on the subject. A PubMed literature search yielded over 2200 publications. Using NASA's 2014 review series 'The effects of sex and gender on adaptation to space' as a benchmark, we identified substantive advancements and persistent knowledge gaps in need of further study from the nearly 600 related articles that have been published since the initial review. This review highlights the most critical issues to mitigate medical risk and promote the success of missions to the Moon and Mars. Salient sex-linked differences observed terrestrially should be studied during upcoming missions, including increased levels of inflammatory markers, coagulation factors and leptin levels following sleep deprivation; correlation between body mass and the severity of spaceflight-associated neuro-ocular syndrome; increased incidence of orthostatic intolerance; increased severity of muscle atrophy and bone loss; differences in the incidence of urinary tract infections; and susceptibility to specific cancers after exposure to ionizing radiation. To optimize health and well-being among all astronauts, it is imperative to prioritize research that considers the physiological nuances of the female body. A more robust understanding of female physiology in the spaceflight environment will support crew readiness for Artemis missions and beyond.

Does Relative Energy Deficiency in Sport (REDs) Syndrome Exist?

Relative energy deficiency in sport (REDs) is a widely adopted model, originally proposed by an International Olympic Committee (IOC) expert panel in 2014 and recently updated in an IOC 2023 consensus statement. The model describes how low energy availability (LEA) causes a wide range of deleterious health and performance outcomes in athletes. With increasing frequency, sports practitioners are diagnosing athletes with "REDs," or "REDs syndrome," based largely upon symptom presentation. The purpose of this review is not to "debunk" REDs but to challenge dogmas and encourage rigorous scientific processes. We critically discuss the REDs concept and existing empirical evidence available to support the model. The consensus (IOC 2023) is that energy availability, which is at the core of REDs syndrome, is impossible to measure accurately enough in the field, and therefore, the only way to diagnose an athlete with REDs appears to be by studying symptom presentation and risk factors. However, the symptoms are rather generic, and the causes likely multifactorial. Here we discuss that (1) it is very difficult to isolate the effects of LEA from other potential causes of the same symptoms (in the laboratory but even more so in the field); (2) the model is grounded in the idea that one factor causes symptoms rather than a combination of factors adding up to the etiology. For example, the model does not allow for high allostatic load (psychophysiological "wear and tear") to explain the symptoms; (3) the REDs diagnosis is by definition biased because one is trying to prove that the correct diagnosis is REDs, by excluding other potential causes (referred to as differential diagnosis, although a differential diagnosis is supposed to find the cause, not demonstrate that it is a pre-determined cause); (4) observational/cross-sectional studies have typically been short duration (< 7 days) and do not address the long term "problematic LEA," as described in the IOC 2023 consensus statement; and (5) the evidence is not as convincing as it is sometimes believed to be (i.e., many practitioners believe REDs is well established). Very few studies can demonstrate causality between LEA and symptoms, most studies demonstrate associations and there is a worrying number of (narrative) reviews on the topic, relative to original research. Here we suggest that the athlete is best served by an unbiased approach that places health at the center, leaving open all possible explanations for the presented symptoms. Practitioners could use a checklist that addresses eight categories of potential causes and involve the relevant experts if and when needed. The Athlete Health and Readiness Checklist (AHaRC) we introduce here simply consists of tools that have already been developed by various expert/consensus statements to monitor and troubleshoot aspects of athlete health and performance issues. Isolating the purported effects of LEA from the myriad of other potential causes of REDs symptoms is experimentally challenging. This renders the REDs model somewhat immune to falsification and we may never definitively answer the question, "does REDs syndrome exist?" From a practical point of view, it is not necessary to isolate LEA as a cause because all potential areas of health and performance improvement should be identified and tackled.

Male Endurance Athletes: Examination of Energy and Carbohydrate Availability and Hormone Responses

BACKGROUND

This study investigated the effects of decreased energy availability (EA) and carbohydrate availability (CA) on reproductive and metabolic hormones in male endurance-trained athletes.

METHODS

Thirteen athletes (age: 26.08 ± 4.3 years; weight: 70.9 ± 6.5 kg; height: 179.9 ± 4.2 cm) participated in two training weeks with varying training volumes (low [LV] and high [HV]). The participants logged their diet and exercise for seven days and provided blood samples to measure hormone levels (Testosterone [T], insulin, leptin, cortisol, and interleukin-6 [IL-6]).

RESULTS

Results showed that 46.2% (HV) and 38.5% (LV) of participants were at risk for low EA (≤25 kcal/kg FFM·d-1), while 53.8% (HV) and 69.2% (LV) had low CA (<6 g/kg). Strong positive correlations were found between leptin and body fat percentage (DXABFP) in both weeks (HV: r(11) = 0.88, p < 0.001; LV: r(11) = 0.93, p < 0.001). Moderate correlations were observed between T and DXABFP (r(11) = 0.56, p = 0.05) and negative correlations between leptin and fat intake (r(11) = -0.60, p = 0.03). Regression analyses indicated significant relationships between DXABFP and T (F(1,11) = 4.91, p = 0.049), leptin (HV: F(1,11) = 40.56, p < 0.001; LV: F(1,11) = 74.67, p < 0.001), and cortisol (F(1,11) = 6.69, p = 0.025).

CONCLUSIONS

These findings suggest that monitoring body composition and macronutrients can be clinically useful for male athletes, especially those without access to blood testing. Ultimately, a greater understanding of health and performance outcomes for male athletes is needed.

Can Trabecular Bone Score Enhance Fracture Risk Assessment in Long-Distance Runners With Bone Stress Injuries?

OBJECTIVE

To evaluate the trabecular bone score (TBS) Z scores in long-distance runners with bone stress injuries (BSIs) in whom the bone mineral density (BMD) Z score is more than -1.0 (Aim 1) and whether the number of runners with abnormal TBS Z scores would be higher in those with BSI in trabecular-rich sites as compared with cortical-rich sites (Aim 2).

DESIGN

Retrospective cohort study.

SETTING

Institutional sports medicine center.

PATIENTS

We analyzed Z scores derived from the TBS and BMD in 44 long-distance runners aged 18 to 40 years who had sustained BSIs between 2017 and 2023 and undergone a dual-energy x-ray absorptiometry scan with reported TBS measurements within 1 year before or 2 years after their injuries.

INDEPENDENT VARIABLES

Bone mineral density and TBS Z scores.

MAIN OUTCOME MEASURES

Evaluation of BMD and TBS Z scores in long-distance runners with BSIs, further stratified according to cortical-rich and trabecular-rich BSIs.

RESULTS

Bone mineral density assessments revealed an average Z score of -0.96 ± 0.99. In this cohort of 44 runners, 55% (n = 24) of runners were reported to have BMD Z score more than -1.0. Within this subgroup, 54% (n = 13) displayed abnormal TBS. Stratifying BSIs by trabecular- (n = 23) and cortical-rich (n = 19) sites, we found no significant difference in sex, mean BMD, or the number of runners with abnormal TBS between the 2 groups.

CONCLUSIONS

Trabecular bone score Z scores in sports medicine may provide complementary information to BMD in long-distance runners with BSI, particularly when the BMD Z scores are more than -1.0. However, further research is needed to validate the usefulness of TBS Z scores in this context.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Retrospective Case Series, IV.

Periodic health evaluation in Para athletes: a position statement based on expert consensus

Para athletes present a broad range of sports-related injuries and illnesses, frequently encountering barriers when accessing healthcare services. The periodic health evaluation (PHE) is a valuable tool for continuously monitoring athletes' health, screening for health conditions, assisting in the surveillance of health problems by establishing baseline information and identifying barriers to athlete's performance. This position statement aims to guide sports healthcare providers in the PHE for Para athletes across key impairment categories: intellectual, musculoskeletal, neurological and vision. A panel of 15 international experts, including epidemiologists, physiotherapists, optometrists and physicians with expertise in Para athlete health, convened via videoconferences to discuss the position statement's purpose, methods and themes. They formed working groups to address clinical, cardiorespiratory, neuromusculoskeletal, nutritional status, mental and sleep health, concussion and female Para athlete health assessment considerations. The PHE's effectiveness lies in its comprehensive approach. Health history review can provide insights into factors impacting Para athlete health, inform physical assessments and help healthcare providers understand each athlete's needs. During the PHE, considerations should encompass the specific requirements of the sport modality and the impairment itself. These evaluations can help mitigate the common tendency of Para athletes to under-report health issues. They also enable early interventions tailored to the athlete's health history. Moreover, the PHE serves as an opportunity to educate Para athletes on preventive strategies that can be integrated into their training routines, enhancing their performance and overall health. This position statement can potentially enhance clinical translation into practice and improve the healthcare quality for Para athletes.

Energy expenditure of international female rugby union players during a major international tournament: a doubly labelled water study

The purpose of this study was to quantify the total energy expenditure (TEE) of international female rugby union players. Fifteen players were assessed over 14 days throughout an international multi-game tournament, which represented two consecutive one-match microcycles. Resting metabolic rate (RMR) and TEE were assessed by indirect calorimetry and doubly labelled water, respectively. Physical activity level (PAL) was estimated (TEE:RMR). Mean RMR, TEE, and PAL were 6.60 ± 0.93 MJ·day-1 (1578 ± 223 kcal·day-1), 13.51 ± 2.28 MJ·day-1 (3229 ± 545 kcal·day-1), and 2.0 ± 0.3 AU, respectively. There was no difference in TEE (13.74 ± 2.31 (3284 ± 554 kcal·day-1) vs. 13.92 ± 2.10 MJ·day-1 (3327 ± 502 kcal·day-1); p = 0.754), or PAL (2.06 ± 0.26 AU vs. 2.09 ± 0.23 AU; p = 0.735) across microcycles, despite substantial decreases in training load (total distance: -8088 m, collisions: -20 n, training duration: -252 min). After correcting for body composition, there was no difference in TEE (13.80 ± 1.74 (3298 ± 416 adj. kcal·day-1) vs. 13.16 ± 1.97 (3145 ± 471 adj. kcal·day-1) adj. MJ·day-1, p = 0.190), RMR (6.49 ± 0.81 (1551 ± 194 adj. kcal·day-1) vs. 6.73 ± 0.83 (1609 ± 198 adj. kcal·day-1) adj. MJ·day-1, p = 0.633) or PAL (2.15 ± 0.14 vs. 1.87 ± 0.26 AU, p = 0.090) between forwards and backs. For an injured participant (n = 1), TEE reduced by 1.7 MJ·day-1 (-401 kcal·day-1) from pre-injury. For participants with illness (n = 3), TEE was similar to pre-illness (+0.49 MJ·day-1 (+117 kcal·day-1)). The energy requirements of international female rugby players were consistent across one-match microcycles. Forwards and backs had similar adjusted energy requirements. These findings are critical to inform the dietary guidance provided to female rugby players.

Measurement of energy availability in highly trained male endurance athletes and examination of its associations with bone health and endocrine function

PURPOSE

Despite the introduction of Relative Energy Deficiency in Sport (RED-s) in 2014, there is evidence to suggest that male endurance athletes still present with a high prevalence of low energy availability (LEA). Previous findings suggest that energy availability (EA) status is strongly correlated with impairments in endocrine function such as reduced leptin, triiodothyronine (T3), and insulin, and elevated bone loss. This study aimed to report the current EA status, endocrine function and bone health of highly trained Irish male endurance athletes.

METHODS

In this cross-sectional study, participants (n = 3 triathletes; n = 10 runners) completed a 7-day testing period during the competition season using lab-based measures, to ascertain EA status, hormone level and rates of bone metabolism. Serum blood samples were obtained to assess hormone levels and markers of bone metabolism.

RESULTS

Mean EA was < 30 kcal/kg lean body mass (LBM)/day in 76.9% of athletes. There was a strong association between LEA and low carbohydrate intake, and lower LBM. Mean levels of insulin, IGF-1 and leptin were significantly lower than their reference ranges. Elevated mean concentrations of β-CTX and a mean P1NP: β-CTX ratio < 100, indicated a state of bone resorption.

CONCLUSION

The EA level, carbohydrate intake, hormone status and bone metabolism status of highly trained male endurance athletes are a concern. Based on the findings of this study, more frequent assessment of EA across a season is recommended to monitor the status of male endurance athletes, in conjunction with nutritional education specific to EA and the associated risks.

Multi-organ transcriptome atlas of a mouse model of relative energy deficiency in sport

Insufficient energy intake to meet energy expenditure demands of physical activity can result in systemic neuroendocrine and metabolic abnormalities in activity-dependent anorexia and relative energy deficiency in sport (REDs). REDs affects >40% of athletes, yet the lack of underlying molecular changes has been a hurdle to have a better understanding of REDs and its treatment. To assess the molecular changes in response to energy deficiency, we implemented the "exercise-for-food" paradigm, in which food reward size is determined by wheel-running activity. By using this paradigm, we replicated several aspects of REDs in female and male mice with high physical activity and gradually reduced food intake, which results in weight loss, compromised bone health, organ-specific mass changes, and altered rest-activity patterns. By integrating transcriptomics of 19 different organs, we provide a comprehensive dataset that will guide future understanding of REDs and may provide important implications for metabolic health and (athletic) performance.

Criteria and Guidelines for Returning to Running Following a Tibial Bone Stress Injury: A Scoping Review

Tibial bone stress injuries (BSIs) are common among long-distance runners. They have a high recurrence rate, and complexity emerges in the wider management and successful return to running. Following a tibial BSI, a critical component of complete rehabilitation is the successful return to running, and there is a lack of consistency or strong evidence to guide this process. The objectives of this review were to outline the criteria used in clinical decision-making prior to resuming running, and to establish evidence-based guidelines for the return to running process following a tibial BSI. Electronic databases including MEDLINE, CINAHL, Scopus, SPORTDiscus and AMED were searched for studies that stated criteria or provided guidelines on the objectives above. Fifty studies met the inclusion criteria and were included. Thirty-nine were reviews or clinical commentaries, three were retrospective cohort studies, two were randomised controlled trials, two were pilot studies, one was a prospective observational study, and three were case studies. Therefore, the recommendations that have been surmised are based on level IV evidence. Decisions on when an athlete should return to running should be shared between clinicians, coaches and the athlete. There are five important components to address prior to introducing running, which are: the resolution of bony tenderness, pain-free walking, evidence of radiological healing in high-risk BSIs, strength, functional and loading tests, and the identification of contributing factors. Effective return to running planning should address the athlete's risk profile and manage the risk by balancing the athlete's interests and reinjury prevention. An individualised graduated return to running programme should be initiated, often starting with walk-run intervals, progressing running distance ahead of speed and intensity, with symptom provocation a key consideration. Contributing factors to the initial injury should be addressed throughout the return to run process.

Gender differences in foot and ankle sporting injuries: A systematic literature review

BACKGROUND

In response to the all-time high of female sports participation, there has been increasing scientific discourse and media interest in women's sporting injuries in recent years. In gender comparable sports the rate of foot and ankle injury for women is higher than for men. There are intrinsic and extrinsic factors which may explain this difference.

METHODS

A systematic literature search was performed according to the PRISMA guidelines of PubMed, Ovid EMBASE and OVID MEDLINE. Relevant key terms were used to narrow the scope of the search prior to screening. Case reports, review articles, paediatric patients, non foot and ankle injuries and combat sports were excluded. We used dual author, two pass screening to arrive at final included studies.

RESULTS

2510 articles were screened after duplicate exclusion. 104 were included in this literature review. We identified lack of reporting gender difference in the literature.We identified that females have higher frequency and severity of injury. We provide an overview of our current understanding of ankle ligament complex injuries, stress fractures, ostochondral lesions of the talus and Achilles tendon rupture. We expand on the evidence of two codes of football, soccer and Australian rules, as a "case study" of how injury patterns differ between genders in the same sport. We identify gender specific characteristics including severity, types of injury, predisposing risk factors, anatomy, endocrinology and biomechanics associated with injuries. Finally, we examine the effect of level of competition on female injury patterns.

CONCLUSIONS

There is a lack of scientific reporting of gender differences of foot and ankle injuries. Female athletes suffer foot and ankle injuries at higher rates and with greater severity compared to males. This is an under-reported, yet important area of orthopaedics and sports medicine to understand, and hence reduce the injury burden for female athletes.

The interplay between gut microbiome and physical exercise in athletes

PURPOSE OF REVIEW

The gut microbiome regulates several health and disease-related processes. However, the potential bidirectional relationship between the gut microbiome and physical exercise remains uncertain. Here, we review the evidence related to the gut microbiome in athletes.

RECENT FINDINGS

The effect of physical exercise on the intestinal microbiome and intestinal epithelial cells depends on the type, volume, and intensity of the activity. Strenuous exercise negatively impacts the intestinal microbiome, but adequate training and dietary planning could mitigate these effects. An increase in short-chain fatty acids (SCFAs) concentrations can modulate signaling pathways in skeletal muscle, contributing to greater metabolic efficiency, preserving muscle glycogen, and consequently optimizing physical performance and recovery. Furthermore, higher SCFAs concentrations appear to lower inflammatory response, consequently preventing an exacerbated immune response and reducing the risk of infections among athletes. Regarding dietary interventions, the optimal diet composition for targeting the athlete's microbiome is not yet known. Likewise, the benefits or harms of using probiotics, synbiotics, and postbiotics are not well established, whereas prebiotics appear to optimize SCFAs production.

SUMMARY

The intestinal microbiome plays an important role in modulating health, performance, and recovery in athletes. SCFAs appear to be the main intestinal metabolite related to these effects. Nutritional strategies focusing on the intestinal microbiome need to be developed and tested in well controlled clinical trials.

Acute and Chronic Weight-Making Practice in Professional Mixed Martial Arts Athletes: An Analysis of 33 Athletes Across 80 Fights

Mixed martial arts' popularity has increased in recent years, alongside descriptive research and evidence-based performance recommendations. Guidelines for (both chronic and acute) weight making exist; however, how these translate in real-life scenarios and detailed investigations on practices in larger groups deserve attention. The present study examined the body mass (BM) and composition of 33 professional mixed martial arts athletes preparing for 80 fights. Athletes were supported by on-site dietitians, who encouraged evidence-based practices. Fasted BM was measured throughout the last ∼10 days before all bouts (acute weight management phase). A subset of athletes had body composition assessed before and after the chronic weight loss phase for 40 fights. Most athletes engaged in chronic BM loss, and all engaged in acute weight loss. Many lost fat-free mass (FFM) during the chronic phase, with rates of BM loss <0.5% best preserving FFM. Regardless of losses, the present athletes possessed greater FFM than other combat sport athletes and engaged in greater acute weight loss. Dehydration in the 24-48 hr before the weigh-in was not reflective of weight regain after the weigh-in, rather BM 7-10 days before the weigh-in was most reflective. These findings suggest that many mixed martial arts athletes could increase FFM at the time of competition by maintaining leaner physiques outside of competition and/or allowing increased time to reduce BM chronically. Acutely, athletes can utilize evidence-based protocols, eliminating carbohydrates, fiber, sodium, and finally fluid in a staged approach, before the weigh-in, reducing the amount of sweating required, thus theoretically better protecting health and preserving performance.

Exploring the relationship between low energy availability, depression and eating disorders in female athletes: a cross-sectional study

Objective

This cross-sectional study aimed to investigate the role of low energy availability (LEA) in the interplay between depression and disordered eating/eating disorders (DE/EDs) among female athletes. The International Olympic Committee consensus statement on Relative Energy Deficiency in Sport (REDs) identified depression as both an outcome of LEA and a secondary risk factor for REDs. However, the direct link between LEA and depression has yet to be fully established.

Methods

We assessed 57 female athletes participating in weight-sensitive sports at different levels of competition training at least four times a week. Assessment was conducted using laboratory analyses, clinical interviews and the Patient Health Questionnaire-9 questionnaire. Participants were recruited through various channels, including German sports clubs, Olympic training centres, social media platforms and the distribution of flyers at competitions. Indicators of LEA were defined if at least two of the following three physiological indicators were present: menstrual disturbances, suppressed resting metabolic rate and suppressed thyroid hormones. Logistic and linear regression analysis were used to examine the relationship between LEA, depression and DE/ED.

Results

The lifetime prevalence of depressive disorders was 29.6%. 19% of the participants were diagnosed with an ED, and an additional 22.6% exhibited DE.LEA was not significantly associated with either lifetime prevalence of depressive disorders or current depressive symptoms. However, a significant association was found between depression and DE/ED in terms of both lifetime prevalence and current depressive symptoms. DE/ED increased the probability of lifetime prevalence of depressive disorders by 34% (19%-49%) compared with normal eating behaviour.

Conclusion

We found no evidence that LEA is an independent factor for depression in female athletes. Its association with LEA and REDs appears to occur primarily in the presence of DE/ED.

Dietary Supplementation on Physical Performance and Recovery in Active-Duty Military Personnel: A Systematic Review of Randomized and Quasi-Experimental Controlled Trials

BACKGROUND

Warfighters, often called tactical athletes, seek dietary supplementation to enhance training and recovery. Roughly 69% of active-duty US military personnel have reported consuming dietary supplements. The objective of this systematic review was to examine the impact of dietary supplements on muscle-related physical performance and recovery in active-duty military personnel.

METHODS

Randomized controlled trials and quasi-experimental controlled trials of oral dietary supplementation in active-duty military members were examined. A protocol was registered (PROSPERO CRD42023401472), and a systematic search of MEDLINE and CINAHL was undertaken. Inclusion criteria consisted of studies published between 1990-2023 with outcomes of muscle performance and recovery among active-duty military populations. The risk of bias was assessed with the McMaster University Guidelines and Critical Review Form for Quantitative Studies.

RESULTS

Sixteen studies were included. Four were conducted on protein or carbohydrate; four on beta-alanine alone, creatine alone, or in combination; two on mixed nutritional supplements; two on probiotics alone or in combination with beta hydroxy-beta methylbutyrate calcium; and four on phytonutrient extracts including oregano, beetroot juice, quercetin, and resveratrol. Ten examined outcomes related to physical performance, and six on outcomes of injury or recovery. Overall, protein, carbohydrate, beta-alanine, creatine, and beetroot juice modestly improved performance, while quercetin did not. Protein, carbohydrates, beta-alanine, probiotics, and oregano reduced markers of inflammation, while resveratrol did not.

CONCLUSIONS

Nutrition supplementation may have small benefits on muscle performance and recovery in warfighters. However, there are significant limitations in interpretation due to the largely inconsistent evidence of ingredients and comparable outcomes. Thus, there is inadequate practical evidence to suggest how dietary supplementation may affect field performance.

Differences in bone mineral density and associated factors in dancers and other female athletes

Dancers are susceptible to relative energy deficiency in sport (RED-S), specifically low bone mineral density (BMD). Little is known about how dancers' BMD compares to other athletic populations. The objective of this study was to examine the association between participant characteristics and total body areal BMD (aBMD) among female pre-professional dancers compared to other female athletes. Two hundred sixty-nine females (132 pre-professional dancers (17.6 (3.2) years) and 137 sport participants (22.8 (2.6) years) were included in this study. aBMD (g/cm2) was estimated using dual X-ray absorptiometry. Multivariable linear regression was used to examine the association between height-adjusted z-scores of total body aBMD (aBMD-Z) and age (years), body mass index (BMI) (z-score), supplement intake, history of stress fracture, irregular menses, MRI/bone scan, 1-year injury history, oral contraceptives, and activity (dance/sport). Total body aBMD and aBMD-Z were lower in dancers than athletes (dancers: aBMD = 1.03 g/cm2 (95% CI: 1.01, 1.05); aBMD-Z = -0.28 (-0.43, -0.12) (p < 0.001); athletes: aBMD = 1.14 g/cm2 (95% CI: 1.12, 1.16); aBMD-Z = 0.41 (0.25, 0.57) (p < 0.001)). aBMD-Z increased with age (β = 0.054, 95% CI: 0.017, 0.092; p = 0.004) and BMI (β = 0.221, 95% CI: 0.006, 0.415; p = 0.043). Activity type modified the relationship between BMI and aBMD-Z (β = 0.323, 95% CI: 0.025, 0.621; p < 0.033) with a stronger positive association in dancers, compared to other female athletes. Dancers had lower total body aBMD and aBMD-Z than other female athletes. aBMD-Z increases with age in female pre-professional dancers and other female athletes. A stronger association exists between aBMD-Z and BMI in dancers than athletes. Future studies should consider changes in aBMD-Z during adolescence and associations with increased risk of bone injury.

Risk of low energy availability, eating disorders and food insecurity amongst development female rugby league players

BACKGROUND

There have been several published studies on the prevalence of low energy availability (LEA) risk amongst North American and European endurance athletes. Yet the prevalence and risk factors amongst rugby league players are less well understood. This study assessed the prevalence of low energy availability risk, eating disorder risk, and food security amongst players from a female National Rugby League squad in Australia.

METHODS

Players from one Australian professional rugby league club volunteered to participate in the study. An online questionnaire was conducted to determine the prevalence of low energy availability (Low Energy Availability in Females Questionnaire [LEAF-Q]), eating disorder risk (Eating Disorders Inventory [EDI-3]), and food security.

RESULTS

Differences between those "at risk" and "not at risk" based on their total LEAF-Q score were determined. Of the 28 players, 64% (N.=18) were at risk of LEA. Raw scores for the EDI-3 subscales, body dissatisfaction (P=0.043), bulimia (P=0.002), composite score (P=0.038), were significantly higher for those at risk and not at risk of LEA. Forty percent of players had some level of food insecurity.

CONCLUSIONS

The results suggest LEA risk is similar to other populations and those at risk of LEA are more likely to have an elevated clinical risk of eating disorders. Food security is also an issue in this population and could contribute to LEA risk for some. Future research is needed amongst team sports athletes to understand interplay between eating disorder risk and food insecurity with LEA risk.

Prevalence of anemia and iron deficiency and its association with body mass index in elite Japanese high school long-distance runners

OBJECTIVES

Anemia is a common condition in long-distance runners (LDRs). Recently, not only iron deficiency (ID) but also energy deficiency has been considered as a risk factor for anemia in athletes but no evidence has yet been established. The aim of this study was to investigate the prevalence of anemia and ID and the influence of body mass index (BMI) on anemia in high-school LDRs.

METHODS

The participants were 406 male and 235 female elite Japanese LDRs who competed in the All-Japan High-School Ekiden Championship 2019. They submitted their anthropometric data and results of a blood test within five days after the competition. The prevalence of anemia and ID and the influence of BMI on anemia were assessed retrospectively.

RESULTS

Mean hemoglobin concentrations (Hb) were 14.8 ± 0.9 g/dl in males and 13.2 ± 0.9 g/dl in females. The prevalence of anemia (Hb < 14 g/dl in males and < 12 g/dl in females) was significantly higher in males (16.3%) than females (6.4%), but males also showed higher prevalence of non-iron deficiency anemia (NIDA) than females (11.6% and 3.0%, respectively). No significant gender difference was found in the prevalence of iron deficiency anemia (IDA) (4.7% in males and 3.4% in females). ID (serum ferritin level < 25 ng/ml) was significantly more prevalent in females (37.4%) than males (18.5%). A binary logistic regression analysis revealed that low BMI was a contributor to anemia in females (odds ratios: 0.577 (95% CI: 0.369-0.901), p = 0.012).

CONCLUSION

In Japanese high-school LDRs, one in six males was anemic, but most males did not have ID. Conversely, one-third of females were diagnosed with ID. Lower BMI was identified as a risk for anemia in females, suggesting that leanness may also lead to anemia in females.

Impact of symptoms, experiences, and perceptions of the menstrual cycle on recreational physical activity of cyclically menstruating individuals: A systematic review

OBJECTIVE

The menstrual cycle often presents barriers to participation in daily life activities, including physical activity (PA), which is a cornerstone of health and well-being. The purpose of this systematic review was to explore and summarize the impact of symptoms, experiences, and perceptions of the menstrual cycle on recreational PA (RPA), including sports, exercise and active recreation, in the general population.

METHODS

Six databases were searched for studies that investigated the impact of the menstrual cycle on PA among individuals who were cyclically menstruating, healthy, and not involved in professional sports training.

RESULTS

The search yielded 3025 studies that were screened for relevance and eligibility, resulting in 25 eligible studies, which were found to be of moderate-to-high quality following a quality and risk-of-bias assessment. Thematic synthesis of qualitative and quantitative data from the selected studies, constituting 16,557 adults and 3715 adolescents, identified the impact of menstrual symptoms on the physical and psychological capability to participate in RPA, social opportunity barriers to RPA (e.g., social pressure due to the sociocultural taboo against menstruation), as well reflective (knowledge) and automatic (habit) motivation on RPA behaviours.

CONCLUSION

The variability in menstrual symptoms and corresponding experiences suggested the need for an individualized approach to RPA promotion. Furthermore, this review highlighted the need to address the sociocultural taboo against menstruation, as well as improve the provision of knowledge and resources related to the menstrual cycle and RPA, in order to promote and facilitate RPA for cyclically menstruating individuals throughout the menstrual cycle.

The relationship between low energy availability, injuries, and bone health in recreational female athletes

Background

Low energy availability (LEA) causes pathophysiology of the female athlete's body affecting the bone and reproductive health and was observed to have a high prevalence in recreational female athletes previously. The aim of this study was to analyse the relationship between low energy availability in females questionnaire (LEAF-Q), bone mineral density (BMD), and postural stability in recreational athletes.

Methods

Recreational female athletes (n = 24, age: 23.71 ± 2.94, Tier I) completed LEAF-Q, postural stability measurement during quiet stance (Zebris platform FDM; GmbH) and their BMD was measured using DXA (Hologic QDR Horizon A). Non-parametric statistical tests were used to analyse the relationships between LEAF-Q, BMD, and postural stability and to compare differences between participants divided by the LEAF-Q score and its subscales.

Results

Risk of LEA was observed in 50% of recreational athletes participating in this study. Up to 46% of participants perceived menstrual bleeding changes related to training and 37.50% experienced menstrual dysfunction. Body composition and body weight fluctuations were observed to affect postural stability and BMD. With the risk score for LEA, the BMD and postural stability were not negatively affected in recreational athletes. However, the high number of recreational athletes in the risk score for LEA and menstrual dysfunctions highlights the need for public health programs aimed to increase awareness of LEA and its health consequences and for open communication about the menstrual cycle. Future longitudinal studies observing LEA, BMD, menstrual function, postural stability, and their interrelationship in female athletes are needed to increase the knowledge of this topic.

Comparison of Australian Football League Women's athletes match day energy and nutrient intake to recommendations

AIMS

This cross-sectional observational study quantified Australian Football League Women's athletes' match volume, and compared match-day dietary intakes against recommendations.

METHODS

Self-report, direct observation, and fluid measurements determined dietary intake (n = 17, 25 ± 4.5 years, 22.8 ± 1.8 kg/m2) on five home match days (early or late starting). Global positioning system software captured match volume. Linear mixed effects models evaluated differences in early versus late match volume and nutrient intakes. Data are presented as mean ± standard deviation.

RESULTS

Athletes covered 6712 ± 622 m during matches, with similar numbers of very high-intensity running efforts over equal distances in early and late matches (early vs. late efforts [no.]: 8.5 ± 4.9 vs. 9.5 ± 5.5; distance [m]: 203 ± 127 vs. 212 ± 113). Across all match days, 71% (n = 12) of athletes met their predicted daily energy requirements. However, 82% (n = 14) failed to meet minimum daily carbohydrate recommendations; intake was lower on early compared with late match days (4.7 g/day vs. 5.4 g/kg/day, p = 0.027). On average, no athletes met carbohydrate recommendations in the 2 h prior to a match and only 24% (n = 4) met recommendations during matches. All athletes met post-match carbohydrate and protein requirements.

CONCLUSION

Athletes cover large distances during games with frequent bursts of high-intensity running. However, they do not adjust their intake to meet the energy demands of competition, with inadequate fuelling prior to and during matches. These findings emphasise the need for greater athlete education and dietary support to maximise strategic fuelling to optimise athletic performance.

Epidemiology of Bone-Stress Injuries and Health Care Use in Pac-12 Cross-Country Athletes

CONTEXT

Bone-stress injury (BSI) is common in collegiate athletes. Injury rates and health care use in running athletes are not well documented.

OBJECTIVE

To describe the rate and classification of injury and associated health care use in collegiate cross-country runners with BSI.

DESIGN

Descriptive epidemiology study.

SETTING

Sports medicine facilities participating in the Pac-12 Health Analytics Program.

PATIENTS OR OTHER PARTICIPANTS

Pac-12 Conference collegiate cross-country athletes.

MAIN OUTCOME MEASURE(S)

Counts of injury and health care resources used for each injury. Injury rates were calculated based on athlete-seasons.

RESULTS

A total of 168 BSIs were reported over 4 seasons from 80 team-seasons (34 men's and 46 women's team-seasons) and 1220 athlete-seasons, resulting in 1764 athletic training services and 117 physician encounters. Bone-stress injuries represented 20% of all injuries reported by cross-country athletes. The average BSI rate was 0.14 per athlete-season. Injury rates were higher in female (0.16) than male (0.10) athletes and higher in the 2019-2020 season (0.20) than the 2020-2021 (0.14), 2018-2019 (0.12), and 2021-2022 (0.10) seasons. Most BSIs occurred in the lower leg (23.8%) and the foot (23.8%). The majority of injuries were classified as overuse and time loss (72.6%) and accounted for most of the athletic training services (75.3%) and physician encounters (72.6%). We found a mean of 10.89 athletic training services per overuse and time-loss injury and 12.20 athletic training services per overuse and non-time-loss injury. Mean occurrence was lower for physician encounters (0.70), prescription medications (0.04), tests (0.75), procedures (0.01), and surgery (0.02) than for athletic training services (10.50).

CONCLUSIONS

Bone-stress injuries are common in collegiate cross-country runners and require considerable athletic training resources. Athletic trainers should be appropriately staffed for this population, and suspected BSIs should be confirmed with a medical diagnosis. Future investigators should track treatment codes associated with BSI to determine best-practice patterns.

Monitoring training, performance, biomarkers, and psychological state throughout a competitive season: a case study of a triathlete

INTRODUCTION

Ironman triathletes undergo high workloads during competition preparation which can result in nonfunctional overreaching or overtraining syndrome if not matched with adequate recovery.

PURPOSE

The purpose of this case study was to observe changes in physiological and psychological status over the course of a competitive season in a free-living triathlete.

METHODS

The subject was a 41-year-old triathlete competing in three 113.1-km events. Over the course of a 40-week period, the participant arrived at the laboratory every 4 weeks and underwent body composition testing via air displacement plethysmography, a blood draw for analysis of various biomarkers, and a treadmill-based lactate threshold test. Workload during training and competitions was monitored via a wearable heart rate-monitoring device.

RESULTS

Throughout the season, training volume remained high (12.5 ± 3.4 h/week) and body mass and fat-free mass (FFM) continuously decreased, while biomarkers including cortisol, testosterone, and markers of immunological status exhibited minor changes. Laboratory performance remained relatively consistent, while competition performance continually improved. Following the completion of the competitive period, training volume decreased, FFM remained below baseline levels, free cortisol increased, and both free and total testosterone decreased.

CONCLUSIONS

Workload and recovery seem to have been properly managed throughout the season, evidenced by minimal fluctuations in endocrine and immunological markers. The reason for changes observed in testosterone, cortisol, and body composition following the last competition is unclear, though it may be attributed to changes in stressors and recovery practices outside of training. It is recommended that athletes follow a structured plan during the transition period into the offseason to ensure recovery of physiological state and to set up a productive offseason.

Do Paralympic athletes suffer from brittle bones? Prevalence and risk factors of low bone mineral density in Paralympic athletes

Background

Bone health may be a concern in Paralympic athletes, given the presence of multiple risk factors predisposing these athletes to low bone mineral density (BMD). Objective: We aimed to assess the prevalence of low BMD among Paralympic athletes participating in various sport disciplines, and to identify potential risk factors for low BMD.

Methods

Seventy Paralympic athletes, of whom 51 % were wheelchair-dependent, were included in this cross-sectional study. BMD of the whole-body, lumbar spine, total hip, and femoral neck were assessed by dual-energy x-ray absorptiometry. Comparisons between groups were conducted by one-way ANOVA, and regression analyses were conducted to identify potential risk factors for low BMD.

Results

The prevalence of low BMD (Z-score < -1.0) was highest at femoral neck (34 %), followed by total hip (31 %), whole-body (21 %), and lumbar spine (18 %). Wheelchair-dependent athletes had significantly lower BMD Z-scores compared to the non-wheelchair-dependent athletes at whole-body level (-0.5 ± 1.4 vs 0.2 ± 1.3; P = 0.04), total hip (-1.1 ± 1.2 vs 0.0 ± 1.1; P < 0.01), and femoral neck (-1.0 ± 1.3 vs -0.1 ± 1.2; P < 0.01). At the lumbar spine, low BMD was completely absent in wheelchair basketball and tennis players. Regression analyses identified body mass, wheelchair dependence, and type of sport, as the main risk factors for low BMD.

Conclusions

In this cohort of Paralympic athletes, low BMD is mainly present at the hip, and to a lesser extent at the whole-body and lumbar spine. The most prominent risk factors for low BMD in Paralympic athletes are related to mechanical loading patterns, including wheelchair use, the type of sport, and body mass.

Seasonal health tracking of Australian Football League Women's athletes

BACKGROUND

Studies evaluating the dietary intake of Australian Football League Women's (AFLW) athletes are few and limited to the preseason. This prospective observational study aims to evaluate seasonal changes in dietary intake and health parameters of professional AFLW athletes.

METHODOLOGY

Dietary intake (3-day weighed food records), body composition (bioelectrical impedance analysis, skinfolds), physical performance (global positioning system, GPS), and iron status (fasted blood sample) were assessed in 19 athletes (24 ± 5 years, 170 ± 6 cm, 22.8 ± 2.1 kg/m2) at three timepoints: start of preseason, end of preseason, and end of competition season. Sociodemographic information, sports nutrition knowledge (SNK), and risk of low energy availability (LEA) questionnaires were completed at the start of preseason.

RESULTS

Mean daily energy and carbohydrate (CHO) intakes were lower than recommendations across all seasons (p < 0.05). Mean daily CHO intake was highest at start of preseason (3.6 g/kg/day), decreased during preseason (3.1 g/day) and remained low during competition (3.2 g/day); >80% of players did not meet minimum recommendations at each timepoint (all, p < 0.05). The sum of seven skinfolds and fat mass (%) decreased during preseason (both, p < 0.05). Serum iron fell within recommended ranges for 95% of athletes at all timepoints. The total distance (m) and number of Very High Intensity (>21 km/h) efforts significantly increased across preseason and decreased during competition (all, p < 0.05). Nutrition knowledge was 'poor', and 42% of athletes were at risk of LEA.

CONCLUSIONS

AFLW athletes do not meet energy and carbohydrate requirements across the preseason and competition seasons, which may impact health and performance if deficits are sustained.

Pilot study of a health promotion intervention in sports clubs

Sports clubs (SCs) are an ideal setting for promoting health. However existing health promotion (HP) interventions in SCs mainly target a single health behavior and men who do sports, and evaluations of such interventions provides little information about their deployment. To overcome these limitations, the PROSCeSS intervention was co-constructed based on the theoretical model of the health-promoting SC and multi-level, multi-determinant health strategies. The aim of this pilot study was to evaluate the deployment of the PROSCeSS intervention and identify the factors influencing its deployment. A qualitative study, using recordings of meetings, email and telephone exchanges, and interviews with project leaders of fourteen SC, was carried out. Although a low number of SCs had completed the intervention, they all considered that they have a role to play in helping their members maintain good health. Their ability to develop HP activities and to implement the intervention was influenced by the resources available, the support they received from their sports federation, and the ability of each project leader to get involved in the intervention. The SCs that deployed the intervention implemented several strategies enabling them to integrate health into the organizational, social, economic, and environmental habits of the SCs and to develop new HP activities, such as adapted sports activity sessions and activities to teach members about first aid, nutrition, and good practices for warming up. This study highlights the importance of understanding the specificities of the contexts in which HP interventions are deployed. Having led to a reworking of the intervention steps and the development of an appropriate evaluation design, it also highlights the essential role of pilot studies in the development and evaluation of interventions.

Sex differences in energy balance, body composition, and metabolic and endocrine markers during prolonged arduous military training

This study investigated sex differences in energy balance, body composition, and metabolic and endocrine markers during prolonged military training. Twenty-three trainees (14 women) completed 44-wk military training (three terms of 14 wk with 2-wk adventurous training). Dietary intake and total energy expenditure were measured over 10 days during each term by weighed food and doubly labeled water. Body composition was measured by dual-energy X-ray absorptiometry (DXA) at baseline and at the end of each term. Circulating metabolic and endocrine markers were measured at baseline and at the end of terms 2 and 3. Absolute energy intake and total energy expenditure were higher, and energy balance was lower, for men than women (P ≤ 0.008). Absolute energy intake and balance were lower, and total energy expenditure was higher, during term 2 than terms 1 and 3 (P < 0.001). Lean mass did not change with training (P = 0.081). Fat mass and body fat increased from term 1 to terms 2 and 3 (P ≤ 0.045). Leptin increased from baseline to terms 2 and 3 in women (P ≤ 0.002) but not in men (P ≥ 0.251). Testosterone and free androgen index increased from baseline to term 3 (P ≤ 0.018). Free thyroxine (T4) decreased and thyroid-stimulating hormone (TSH) increased from baseline to term 2 and term 3 (P ≤ 0.031). Cortisol decreased from baseline to term 3 (P = 0.030). IGF-I and total triiodothyronine (T3) did not change with training (P ≥ 0.148). Men experienced greater energy deficits than women during military training due to higher total energy expenditure.NEW & NOTEWORTHY Energy deficits are common in military training and can result in endocrine and metabolic disturbances. This study provides first investigation of sex differences in energy balance, body composition, and endocrine and metabolic markers in response to prolonged and arduous military training. Men experienced greater energy deficits than women due to higher energy expenditure, which was not compensated for by increased energy intake. These energy deficits were not associated with decreases in fat or lean mass or metabolic or endocrine function.

Nutrition in Women at High Altitude: A Scoping Review-UIAA Medical Commission Recommendations

Andjelkovic, Marija, Peter Paal, Susi Kriemler, Kaste Mateikaite-Pipiriene, Alison Rosier, Beth Beidleman, Mia Derstine, Jacqueline Pichler Hefti, David Hillebrandt, Lenka Horakova, Dominique Jean, and Linda E. Keyes. Nutrition in women at high altitude: a scoping review-UIAA Medical Commission recommendations. High Alt Med Biol. 25:9-15, 2024. Background: Nutritional concerns such as food composition, energy intake, and nutrient absorption are essential for performance at high altitude and may differ between men and women. We performed a scoping review to summarize what is currently known on nutrition for women during short-term, high-altitude, physically active sojourns. Methods: The UIAA Medical Commission convened an international team to review women's health issues at high altitude and to publish updated recommendations. Pertinent literature from PubMed and Cochrane was identified by keyword search combinations (including nutrition, metabolism, energy composition, micronutrients) with additional publications found by hand search. Results: We found 7,165 articles, of which 13 original articles assessed nutritional aspects in physically active women on short-term high-altitude sojourns, with other articles found by hand search. We summarize the main findings. Conclusions: Data on women's nutrition at altitude are very limited. Reduction in energy intake plus increased energy expenditure at high altitude can lead to unbalanced nutrition, negatively influencing high-altitude adaptation and physical performance. Therefore, adequate dietary and fluid intake is essential to maintaining energy balance and hydration at high altitude in women as in men. Iron supplementation should be considered for women with iron depletion before travel.

Perspectives on Concurrent Strength and Endurance Training in Healthy Adult Females: A Systematic Review

BACKGROUND

Both strength and endurance training are included in global exercise recommendations and are the main components of training programs for competitive sports. While an abundance of research has been published regarding concurrent strength and endurance training, only a small portion of this research has been conducted in females or has addressed their unique physiological circumstances (e.g., hormonal profiles related to menstrual cycle phase, menstrual dysfunction, and hormonal contraceptive use), which may influence training responses and adaptations.

OBJECTIVE

The aim was to complete a systematic review of the scientific literature regarding training adaptations following concurrent strength and endurance training in apparently healthy adult females.

METHODS

A systematic electronic search for articles was performed in July 2021 and again in December 2022 using PubMed and Medline. This review followed, where applicable, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using a modified Downs and Black checklist. Inclusion criteria were (1) fully published peer-reviewed publications; (2) study published in English; (3) participants were healthy normal weight or overweight females of reproductive age (mean age between > 18 and < 50) or presented as a group (n > 5) in studies including both females and males and where female results were reported separately; (4) participants were randomly assigned to intervention groups, when warranted, and the study included measures of maximal strength and endurance performance; and (5) the duration of the intervention was ≥ 8 weeks to ensure a meaningful training duration.

RESULTS

Fourteen studies met the inclusion criteria (seven combined strength training with running, four with cycling, and three with rowing or cross-country skiing). These studies indicated that concurrent strength and endurance training generally increases parameters associated with strength and endurance performance in female participants, while several other health benefits such as, e.g., improved body composition and blood lipid profile were reported in individual studies. The presence of an "interference effect" in females could not be assessed from the included studies as this was not the focus of any included research and single-mode training groups were not always included alongside concurrent training groups. Importantly, the influence of concurrent training on fast-force production was limited, while the unique circumstances affecting females were not considered/reported in most studies. Overall study quality was low to moderate.

CONCLUSION

Concurrent strength and endurance training appears to be beneficial in increasing strength and endurance capacity in females; however, multiple research paradigms must be explored to better understand the influence of concurrent training modalities in females. Future research should explore the influence of concurrent strength and endurance training on fast-force production, the possible presence of an "interference effect" in athletic populations, and the influence of unique circumstances, such as hormone profile, on training responses and adaptations.

Eating Behavior Disorders and Disordered Eating Habits in Spanish High-Performance Women's Olympic Wrestling Athletes

Eating disorders (EDs) are a significant health issue in combat sports. This study investigated the differences between the different types of female wrestlers and the frequency at which EDs occur in the elite population, and it also sought to establish which factors are predictors of EDs. This study was comprised of 22 elite, female wrestlers who were selected based on the following inclusion criteria: having previously been the Spanish champion, being part of the Spanish national team, participating in at least one international championship, and having a history of ED. Data collection involved five questionnaires: demographic data, the Eating Attitudes Test-26 (EAT-26), the Bulimic Investigatory Test, the Edinburgh (BITE), the Eating Disorders Inventory (EDI-3), and the Depression, Anxiety, and Stress Scale (DASS-21). The results revealed diverse levels of depression, anxiety, and stress, with BITE scores indicating abnormal eating patterns. Group comparisons exposed significant distinctions in eating behaviors based on competition and training experience. Regression analyses showed competition and training experience as predictors of bulimia severity and symptoms. The study revealed prevalent extreme weight-control practices, including fasting, diuretic and laxative use, and binge eating. This research emphasizes the importance of EDs in Olympic wrestling, urging a comprehensive approach involving education, support, and policy implementation by coaches, health professionals, and sports organizations to prioritize athletes' well-being and discourage unhealthy weight-control practices.

A systematic review, meta-analysis, and meta-regression of the prevalence of self-reported disordered eating and associated factors among athletes worldwide

BACKGROUND

The purpose of this meta-analysis was to provide a pooled prevalence estimate of self-reported disordered eating (SRDE) in athletes based on the available literature, and to identify risk factors for their occurrence.

METHODS

Across ten academic databases, an electronic search was conducted from inception to 7th January 2024. The proportion of athletes scoring at or above predetermined cutoffs on validated self-reporting screening measures was used to identify disordered eating (DE). Subgroup analysis per country, per culture, and per research measure were also conducted. Age, body mass index (BMI), and sex were considered as associated/correlated factors.

RESULTS

The mean prevalence of SRDE among 70,957 athletes in 177 studies (132 publications) was 19.23% (17.04%; 21.62%), I2 = 97.4%, τ2 = 0.8990, Cochran's Q p value = 0. Australia had the highest percentage of SRDE athletes with a mean of 57.1% (36.0%-75.8%), while Iceland had the lowest, with a mean of 4.9% (1.2%-17.7%). The SRDE prevalence in Eastern countries was higher than in Western countries with 29.1% versus 18.5%. Anaerobic sports had almost double the prevalence of SRDE 37.9% (27.0%-50.2%) compared to aerobic sports 19.6% (15.2%-25%). Gymnastics sports had the highest SRDE prevalence rate, with 41.5% (30.4%-53.6%) while outdoor sports showed the lowest at 15.4% (11.6%-20.2%). Among various tools used to assess SRDE, the three-factor eating questionnaire yielded the highest SRDE rate 73.0% (60.1%-82.8%). Meta-regression analyses showed that female sex, older age, and higher BMI (all p < 0.01) are associated with higher prevalence rates of SRDE.

CONCLUSION

The outcome of this review suggests that factors specific to the sport affect eating behaviors throughout an athlete's life. As a result, one in five athletes run the risk of developing an eating disorder. Culture-specific and sport-specific diagnostic tools need to be developed and increased attention paid to nutritional deficiencies in athletes.

Differences in screening and treating relative energy deficiency in sport between the United States of America and Japan

BACKGROUND

The diagnosis and treatment of relative energy deficiency in sport (RED-S) are challenging owing to variations in symptoms and the absence of specific guidelines. This study aimed to investigate differences in the diagnosis and follow-up of RED-S, its consequences, and related factors among sports medicine physicians with different backgrounds in Japan and the USA and examine the differences between the two countries.

METHODS

An anonymous survey regarding the diagnosis and treatment processes of RED-S was distributed to sports medicine physicians via email. Respondents included 58 sports medicine physicians from the USA and 241 from Japan.

RESULTS

The findings showed that 77.6% of the US physicians screened athletes for RED-S, whereas 17.5% of their Japanese counterparts did so. Moreover, 98.3% and 36.7% of the US and Japanese physicians, respectively, answered that they screened athletes for eating disorders upon suspicion of low energy availability. Logistic regression analysis revealed that the number of US sports medicine physicians who screened athletes for the female athlete triad (Triad) and RED-S (odds ratio [OR] = 12.78, P<0.001) and adhered to specific criteria for athlete suspension and return-to-play (OR=33.67, P<0.01) was higher than that of their Japanese counterparts.

CONCLUSIONS

The prevalence of RED-S-related screening and treatment differed between US and Japanese sports medicine physicians. Educating sports medicine physicians about the diagnosis and treatment of athletes with possible signs of RED-S is important in treating female athletes and further investigations are required to identify why the physicians screened/not screened the athletes.

Continuous Glucose Monitoring in Endurance Athletes: Interpretation and Relevance of Measurements for Improving Performance and Health

Blood glucose regulation has been studied for well over a century as it is intimately related to metabolic health. Research in glucose transport and uptake has also been substantial within the field of exercise physiology as glucose delivery to the working muscles affects exercise capacity and athletic achievements. However, although exceptions exist, less focus has been on blood glucose as a parameter to optimize training and competition outcomes in athletes with normal glucose control. During the last years, measuring glucose has gained popularity within the sports community and successful endurance athletes have been seen with skin-mounted sensors for continuous glucose monitoring (CGM). The technique offers real-time recording of glucose concentrations in the interstitium, which is assumed to be equivalent to concentrations in the blood. Although continuous measurements of a parameter that is intimately connected to metabolism and health can seem appealing, there is no current consensus on how to interpret measurements within this context. Well-defined approaches to use glucose monitoring to improve endurance athletes' performance and health are lacking. In several studies, blood glucose regulation in endurance athletes has been shown to differ from that in healthy controls. Furthermore, endurance athletes regularly perform demanding training sessions and can be exposed to high or low energy and/or carbohydrate availability, which can affect blood glucose levels and regulation. In this current opinion, we aim to discuss blood glucose regulation in endurance athletes and highlight the existing research on glucose monitoring for performance and health in this population.

Body Composition Changes in Male and Female Elite Soccer Players: Effects of a Nutritional Program Led by a Sport Nutritionist

BACKGROUND

Soccer is a game in constant evolution and the intensity of play is increasing. Nutrition can play a role in the physical performance of elite players, maintaining their health and facilitating recovery. It is important to cover players' energy demands, and low energy availability may therefore result in impaired performance. This study aimed to evaluate alterations in body composition to determine the effects of a nutritional program led by a sport nutritionist.

METHODS

A group of 88 elite soccer players from a Serie A club in Italy (44 males aged 26.5 ± 3.0 years and 44 females aged 27.1 ± 5.2 years) were enrolled. To evaluate changes in body composition, bioimpedance and anthropometric measurements were obtained following the protocol of the International Society for the Advancement of Kinanthropometry (ISAK).

RESULTS

Compared with females, males had more muscle mass and less fat mass in both seasons evaluated. Comparing the first and last seasons, the male soccer players showed increased muscle mass and decreased fat mass while the female soccer players only showed decreased fat mass.

CONCLUSIONS

The presence of a specialist sport nutritionist on the staff of professional soccer clubs could be important to ensure energy availability and evaluate body composition during the season.

Limits of Ultra: Towards an Interdisciplinary Understanding of Ultra-Endurance Running Performance

Ultra-endurance running (UER) poses extreme mental and physical challenges that present many barriers to completion, let alone performance. Despite these challenges, participation in UER events continues to increase. With the relative paucity of research into UER training and racing compared with traditional endurance running distance (e.g., marathon), it follows that there are sizable improvements still to be made in UER if the limitations of the sport are sufficiently understood. The purpose of this review is to summarise our current understanding of the major limitations in UER. We begin with an evolutionary perspective that provides the critical background for understanding how our capacities, abilities and limitations have come to be. Although we show that humans display evolutionary adaptations that may bestow an advantage for covering large distances on a daily basis, these often far exceed the levels of our ancestors, which exposes relative limitations. From that framework, we explore the physiological and psychological systems required for running UER events. In each system, the factors that limit performance are highlighted and some guidance for practitioners and future research are shared. Examined systems include thermoregulation, oxygen delivery and utilisation, running economy and biomechanics, fatigue, the digestive system, nutritional and psychological strategies. We show that minimising the cost of running, damage to lower limb tissue and muscle fatigability may become crucial in UER events. Maintaining a sustainable core body temperature is critical to performance, and an even pacing strategy, strategic heat acclimation and individually calculated hydration all contribute to sustained performance. Gastrointestinal issues affect almost every UER participant and can be due to a variety of factors. We present nutritional strategies for different event lengths and types, such as personalised and evidence-based approaches for varying types of carbohydrate, protein and fat intake in fluid or solid form, and how to avoid flavour fatigue. Psychology plays a vital role in UER performance, and we highlight the need to be able to cope with complex situations, and that specific long and short-term goal setting improves performance. Fatigue in UER is multi-factorial, both physical and mental, and the perceived effort or level of fatigue have a major impact on the ability to continue at a given pace. Understanding the complex interplay of these limitations will help prepare UER competitors for the different scenarios they are likely to face. Therefore, this review takes an interdisciplinary approach to synthesising and illuminating limitations in UER performance to assist practitioners and scientists in making informed decisions in practice and applicable research.