Inducing low energy availability in trained endurance male athletes results in poorer explosive power

The Temporal Effects of Altitude and Low Energy Availability Manipulation on Resting Metabolic Rate in Female Race Walkers

PURPOSE

This study aimed to investigate the temporal effects of ~1800 m altitude exposure and energy availability (EA) manipulation on resting metabolic rate (RMR).

METHODS

Twenty elite female race walkers underwent a 3-wk training camp at an altitude of ~1800 m. During the first 2 wk, athletes consumed a high EA (HEA) diet of 45 kcal·kg fat-free mass (FFM) -1 ·d -1 . During the final week, half the athletes consumed a low EA (LEA) diet of 15 kcal·kg FFM -1 ·d -1 , whereas the others continued on an HEA diet. Athletes followed individualized training plans throughout the study. To assess the effect of altitude on RMR, athletes in the HEA group had RMR measured at baseline (~580 m) before altitude exposure (Pre-alt), at 36 h (36h-alt), 2 wk (Wk2-alt), and 3 wk into altitude exposure (Wk3-alt), and at 36 h post-altitude exposure at ~580 m (36h-post). To assess the effect of LEA exposure on RMR while at altitude, athletes in the LEA group underwent RMR measurements at Pre-alt and before (Wk2-alt) and after the 7 d of LEA (Wk3-alt).

RESULTS

Compared with Pre-alt, the RMR of HEA athletes was increased at 36h-alt (+5.3% ± 3.1%; P = 0.026) and Wk2-alt (+4.9% ± 4.9%; P = 0.049), but was no longer elevated at Wk3-alt (+1.7% ± 4.2%; P = 0.850). The RMR of HEA athletes at 36h-post was lower than all timepoints at altitude ( P < 0.05) but was not different from Pre-alt (-3.9% ± 7.2%; P = 0.124). The 7-d period of LEA exposure at altitude did not affect RMR ( P = 0.347).

CONCLUSIONS

RMR was transiently increased with ~1800-m altitude exposure in female athletes and was unaffected by short-term LEA. However, the altitude-induced increase was small (~25-75 kcal·d -1 ) and was unlikely to have clinically significant implications for daily energy requirements.

Low Energy Availability and Relative Energy Deficiency in Sport: A Systematic Review and Meta-analysis

INTRODUCTION

Low energy availability (LEA) occurs when energy expenditure from athletic training and bodily functions exceeds caloric intake. This imbalance results in declines in athletic performance and increases the risk of injury. Relative energy deficiency in sport (REDs) is a condition that occurs when the energy deficit is severe enough to cause alterations to metabolic rate, menstrual function, immune function, bone health, protein synthesis, and cardiovascular function. Many athletes, particularly those competing in endurance, aesthetic, or weight-class sports, are adversely impacted by this condition.

OBJECTIVES

This study aims to determine the prevalence of LEA and REDs among athletes and present the first secondary analysis of the impacts of these phenomena on sports performance and risk of injury.

METHODS

This systematic review was registered on PROSPERO (CRD42023469253). Literature searches were performed following PRISMA guidelines using PubMed, Embase, and Cochrane online databases. Inclusion criteria were articles discussing the prevalence of LEA or REDs, the impact of LEA or REDs on athletic performance, or the impact of LEA or REDs EA on injury.

RESULTS

A total of 59 studies met the inclusion criteria for this meta-analysis, and 2737 of 6118 athletes (44.7%) in 46 different studies were determined to have LEA, including 44.2% of female athletes and 49.4% of male athletes. In addition, 460 of 730 athletes (63.0%) in eight different studies were determined to be at risk of REDs. Athletes with LEA were found to have decreased run performance, training response, endurance performance, coordination, concentration, judgment, explosive power, and agility relative to athletes with normal energy availability, as well as an increased likelihood of absence from training due to illness. Studies had mixed results as to whether LEA increased the risk of injury in general. However, most studies concluded that athletes with LEA have impaired bone health and a higher risk of bone stress injuries.

DISCUSSION

To our knowledge, this is the first systematic review analyzing the impacts of LEA and REDs on athletic performance and risk of injury. Due to the high estimated prevalence of LEA among athletes, coaches may want to consider employing surveys such as the low energy availability in females questionnaire (LEAF-Q) to identify athletes at risk for LEA, as early identification and correction of LEA can prevent the development of symptoms of REDs, reduce the risk of impaired bone health and bone stress injuries, and help athletes optimize the performance benefits from their training.

Effects of low energy availability on performance in male athletes: A scoping review

OBJECTIVES

The primary aim of this study was to investigate the effects of low energy availability on different performance outcomes in male athletes. Secondary aims were to examine an assumed dose-response relationship and identify knowledge gaps.

DESIGN

Scoping review.

METHODS

The electronic database PubMed was searched until the end of June 2023. Additionally, we used reference tracking and hand-searching for related articles. Six studies with a total of 103 male athletes met the inclusion criteria.

RESULTS

Four of the included studies had an interventional study design, including one case study, and the remaining two were cross-sectional studies. Different performance outcomes (i.e., strength, endurance, speed) were either positively, negatively, or unaffected by low energy availability. The length and magnitude of the low energy availability, as well as the baseline status of the athletes could have influenced the results. Additionally, there are methodological considerations that might limit the validity of the results.

CONCLUSIONS

Current evidence shows heterogeneous results, as some studies suggested improvements in certain performance parameters, whilst other studies showed neutral or detrimental effects of low energy availability. Due to the limitations mentioned; additional research is warranted for a more comprehensive understanding.

Dietary intake, energy availability, and power in men collegiate gymnasts

Introduction

The purpose was to examine the prevalence of low energy availability (LEA), explore dietary behaviors in men collegiate gymnasts (n = 14), and investigate the relationships between energy availability (EA), body composition, and plyometric performance.

Methods

Body composition was measured using air displacement plethysmography. Lower- and upper-body peak power (PWRpeak) and modified reactive strength index (RSImod) were calculated from countermovement jump (CMJ) and plyometric push-up (PP) assessments. Energy expenditure was tracked over 3 days, while daily energy and macronutrient intake were recorded. EA was calculated and used to categorize athletes into LEA and non-LEA groups. Pearson correlation coefficients were used to examine relationships between EA, body composition, and performance metrics.

Results

85.7% of athletes (n = 12) exhibited LEA (20.98 ± 5.2 kcals/kg FFM), with non-LEA athletes (n = 2) marginally surpassing the <30 kcal/kg of fat-free mass (FFM) threshold (30.58 ± 0.2 kcals/kg FFM). The cohort (n = 14) consumed insufficient energy (30.5 ± 4.5 kcal/kg/day) and carbohydrates (3.7 ± 1.1 g/kg/day), resulting in LEA (22.36 ± 5.9 kcal/kg/FFM). EA was not correlated with body composition or performance metrics.

Discussion

A high prevalence of LEA may exist in men gymnasts, largely due to a low relative energy and carbohydrate intake.

Relative Energy Deficiency in Sport (REDs): Endocrine Manifestations, Pathophysiology and Treatments

Research on lean, energy-deficient athletic and military cohorts has broadened the concept of the Female Athlete Triad into the Relative Energy Deficiency in Sport (REDs) syndrome. REDs represents a spectrum of abnormalities induced by low energy availability (LEA), which serves as the underlying cause of all symptoms described within the REDs concept, affecting exercising populations of either biological sex. Both short- and long-term LEA, in conjunction with other moderating factors, may produce a multitude of maladaptive changes that impair various physiological systems and adversely affect health, well-being, and sport performance. Consequently, the comprehensive definition of REDs encompasses a broad spectrum of physiological sequelae and adverse clinical outcomes related to LEA, such as neuroendocrine, bone, immune, and hematological effects, ultimately resulting in compromised health and performance. In this review, we discuss the pathophysiology of REDs and associated disorders. We briefly examine current treatment recommendations for REDs, primarily focusing on nonpharmacological, behavioral, and lifestyle modifications that target its underlying cause-energy deficit. We also discuss treatment approaches aimed at managing symptoms, such as menstrual dysfunction and bone stress injuries, and explore potential novel treatments that target the underlying physiology, emphasizing the roles of leptin and the activin-follistatin-inhibin axis, the roles of which remain to be fully elucidated, in the pathophysiology and management of REDs. In the near future, novel therapies leveraging our emerging understanding of molecules and physiological axes underlying energy availability or lack thereof may restore LEA-related abnormalities, thus preventing and/or treating REDs-related health complications, such as stress fractures, and improving performance.

Identifying and Analyzing Low Energy Availability in Athletes: The Role of Biomarkers and Red Blood Cell Turnover

Low energy availability (LEA) is a growing concern that can lead to several problems for athletes. However, adaptation to LEA occurs to maintain balance over time, making diagnosis difficult. In this review, we categorize LEA into two phases: the initial phase leading to adaptation and the phase in which adaptation is achieved and maintained. We review the influence of LEA on sports performance and health and discuss biomarkers for diagnosing LEA in each phase. This review also proposes future research topics for diagnosing LEA, with an emphasis on the recently discovered association between red blood cell turnover and LEA.

Impact of Equation Choice on Resting Metabolic Rate Ratio in High-Level Men and Women Athletes

OBJECTIVE

To examine the impact of the RMR ratio cutoff point selected on the categorization of prevalence/absence of low energy availability among predictive equations in high-level athletes (n = 241 [99 women]; 52% competed at the World Championship and Olympic Games), and whether this categorization is influenced by sex and the predictive equation used.

METHODS

We assessed RMR using indirect calorimetry, predicted the RMR using the equations proposed by Harris-Benedict, FAO/WHO/UNU, de Lorenzo, ten Haaf and Wejis, Wong, Jagim, Cunningham, and Freire, and computed the RMR ratio for each equation.

RESULTS

We observed that the cumulative percentage of RMR ratio values increased at a faster rate using Jagim, ten Haaf and Wejis, and Cunningham equations compared to the other equations. At the 0.90 value (the most used cutoff point in literature), the Jagim equation categorized ≥ 50% of the athletes into "low energy availability". No Sex × Equation × Sport interaction effect was observed (F = 0.10, p = 1.0). There was a significant main effect to Sex (F = 11.7, p < 0.001, ES = 0.05), Sport (F = 16.4, p < 0.001, ES = 0.01), and Equation (F = 64.1, p < 0.001, ES = 0.19). Wong and FAO/WHO/UNU equations yielded the largest errors (assessed vs. predicted RMR) in men and women, respectively.

CONCLUSION

The selected RMR ratio cutoff point influences the prevalence/absence of low energy availability characterization in high-level athletes and suggests that certain equations could bias its assessment.

A real-life snapshot: Evaluating exposures to low energy availability in male athletes from various sports

Problematic low energy availability (LEA) is the underlying cause of relative energy deficiency in sport (REDs). Male specific etiology, as well as the duration and degree of LEA exposures resulting in REDs remain to be adequately described. The present study aimed to assess occurrences of LEA (energy availability [EA] <25 kcal/kg fat-free mass/day) in male athletes from various sports over 7 days. Associations between number of LEA days, physiological measures, and body image concerns were subsequently evaluated. The athletes recorded their weighed food intakes and training via photo-assisted mobile application. Body composition and resting metabolic rates were measured, and venous blood samples collected for assessments of hormonal and nutrition status. Participants also answered the Low Energy Availability in Males Questionnaire (LEAM-Q), Eating Disorder Examination-Questionnaire Short (EDE-QS), Exercise Addiction Inventory (EAI), and Muscle Dysmorphic Disorder Inventory (MDDI). Of 19 participants, 13 had 0-2, 6 had 3-5, and none had 6-7 LEA days. No associations were found between the number of LEA days with the physiological and body image outcomes, although those with greatest number of LEA days had highest EEE but relatively low dietary intakes. In conclusion, this group displayed considerable day-to-day EA fluctuations but no indication of problematic LEA.

The risk of low energy availability among athlete females in Saudi Arabia: a cross-sectional study

Introduction

Low energy availability (LEA) is a state of inadequate energy reserves that results from a negative energy balance. This condition can lead to severe health risks such as amenorrhea and osteoporosis. Various causes for LEA, such as eating disorders and exercise addiction, have been reported in the literature. However, data in Saudi Arabia are lacking. This cross-sectional study measures the prevalence of LEA, eating disorders, and exercise addiction among adult females in Saudi Arabia and identifies possible associated risk factors.

Methods

The sample comprised 119 female athletes who filled out an online survey adapted from the LEA in Females Questionnaire, the Eating Disorder Examination Questionnaire, and the Exercise Addiction Inventory.

Results

Participants showed a high prevalence of LEA (66.4%), eating disorder (33.6%), and exercise addiction (10.1%), confirming the association between normal weight and LEA in females living in Saudi Arabia (p < 0.00).

Discussion and conclusion

With an increasing number of females in the country interested in following a healthy lifestyle, there is a need to raise the awareness of the population on the issues of LEA, eating disorders, and exercise addiction and their effects on the body by developing educational programs about energy intake and healthy physical activity routines.

Patterns of energy availability and carbohydrate intake differentiate between adaptable and problematic low energy availability in female athletes

Background

Problematic low energy availability (EA) is the underlying culprit of relative energy deficiency in sport (REDs), and its consequences have been suggested to be exacerbated when accompanied by low carbohydrate (CHO) intakes.

Objectives

This study compared dietary intake, nutrition status and occurrence of REDs symptoms in groups of female athletes, displaying different patterns of EA and CHO intake.

Methods

Female athletes (n = 41, median age 20.4 years) from various sports weighed and recorded their food intake and training for 7 consecutive days via a photo-assisted mobile application. Participants were divided into four groups based on patterns of EA and CHO intakes: sufficient to optimal EA and sufficient to optimal CHO intake (SEA + SCHO), SEA and low CHO intake (SEA + LCHO), low energy availability and SCHO (LEA + SCHO), and LEA and LCHO (LEA + LCHO). SEA patterns were characterised by EA ≥30 and LEA by EA <30 kcal/kg fat free mass, and SCHO patterns characterised by CHO intake ≥3.0 and LCHO <3.0 g/kg body weight for most of the registered days. Body composition was measured with dual energy x-ray absorptiometry, resting metabolic rate with indirect calorimetry and serum blood samples were collected for evaluation of nutrition status. Behavioural risk factors and self-reported symptoms of REDs were assessed with the Low Energy Availability in Females Questionnaire, Eating Disorder Examination Questionnaire Short (EDE-QS), Exercise Addiction Inventory, and Muscle Dysmorphic Disorder Inventory.

Results

In total, 36.6% were categorised as SEA + SCHO, of which 5/16 were ball sport, 7/10 endurance, 1/7 aesthetic, 2/5 weight-class, and 0/3 weight-class athletes. Of LEA + LCHO athletes (19.5% of all), 50% came from ball sports. Aesthetic and endurance athletes reported the greatest training demands, with weekly training hours higher for aesthetic compared to ball sports (13.1 ± 5.7 vs. 6.7 ± 3.4 h, p = 0.012). Two LEA + LCHO and one SEA + LCHO athlete exceeded the EDE-QS cutoff. LEA + LCHO evaluated their sleep and energy levels as worse, and both LEA groups rated their recovery as worse compared to SEA + SCHO.

Conclusion

Repeated exposures to LEA and LCHO are associated with a cluster of negative implications in female athletes. In terms of nutrition strategies, sufficient EA and CHO intakes appear to be pivotal in preventing REDs.

Association between Low Energy Availability (LEA) and Impaired Sleep Quality in Young Rugby Players

Low energy availability (LEA) has been associated with several physiological consequences, but its impact on sleep has not been sufficiently investigated, especially in the context of young athletes. This study examined the potential association between energy availability (EA) status and objective sleep quality in 42 male rugby players (mean age: 16.2 ± 0.8 years) during a 7-day follow-up with fixed sleep schedules in the midst of an intensive training phase. Participants' energy intake was weighed and recorded. Exercise expenditure was estimated using accelerometry. Portable polysomnography devices captured sleep on the last night of the follow-up. Mean EA was 29.3 ± 9.14 kcal·kg FFM-1·day-1, with 47.6% of athletes presenting LEA, 35.7% Reduced Energy Availability (REA), and 16.7% Optimal Energy Availability (OEA). Lower sleep efficiency (SE) and N3 stage proportion, along with higher wake after sleep onset (WASO), were found in participants with LEA compared to those with OEA (p = 0.04, p = 0.03 and p = 0.005, respectively, with large effect sizes). Segmented regression models of the EA-sleep outcomes (SE, sleep onset latency [SOL]), WASO and N3) relationships displayed two separate linear regions and produced a best fit with a breakpoint between 21-33 kcal·kg FFM-1·day-1. Below these thresholds, sleep quality declines considerably. It is imperative for athletic administrators, nutritionists, and coaches to conscientiously consider the potential impact of LEA on young athletes' sleep, especially during periods of heavy training.

2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs)

Relative Energy Deficiency in Sport (REDs) was first introduced in 2014 by the International Olympic Committee's expert writing panel, identifying a syndrome of deleterious health and performance outcomes experienced by female and male athletes exposed to low energy availability (LEA; inadequate energy intake in relation to exercise energy expenditure). Since the 2018 REDs consensus, there have been >170 original research publications advancing the field of REDs science, including emerging data demonstrating the growing role of low carbohydrate availability, further evidence of the interplay between mental health and REDs and more data elucidating the impact of LEA in males. Our knowledge of REDs signs and symptoms has resulted in updated Health and Performance Conceptual Models and the development of a novel Physiological Model. This Physiological Model is designed to demonstrate the complexity of either problematic or adaptable LEA exposure, coupled with individual moderating factors, leading to changes in health and performance outcomes. Guidelines for safe and effective body composition assessment to help prevent REDs are also outlined. A new REDs Clinical Assessment Tool-Version 2 is introduced to facilitate the detection and clinical diagnosis of REDs based on accumulated severity and risk stratification, with associated training and competition recommendations. Prevention and treatment principles of REDs are presented to encourage best practices for sports organisations and clinicians. Finally, methodological best practices for REDs research are outlined to stimulate future high-quality research to address important knowledge gaps.

Mapping the complexities of Relative Energy Deficiency in Sport (REDs): development of a physiological model by a subgroup of the International Olympic Committee (IOC) Consensus on REDs

The 2023 International Olympic Committee (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs) notes that exposure to low energy availability (LEA) exists on a continuum between adaptable and problematic LEA, with a range of potential effects on both health and performance. However, there is variability in the outcomes of LEA exposure between and among individuals as well as the specific manifestations of REDs. We outline a framework for a 'systems biology' examination of the effect of LEA on individual body systems, with the eventual goal of creating an integrated map of body system interactions. We provide a template that systematically identifies characteristics of LEA exposure (eg, magnitude, duration, origin) and a variety of moderating factors (eg, medical history, diet and training characteristics) that could exacerbate or attenuate the type and severity of impairments to health and performance faced by an individual athlete. The REDs Physiological Model may assist the diagnosis of underlying causes of problems associated with LEA, with a personalised and nuanced treatment plan promoting compliance and treatment efficacy. It could also be used in the strategic prevention of REDs by drawing attention to scenarios of LEA in which impairments of health and performance are most likely, based on knowledge of the characteristics of the LEA exposure or moderating factors that may increase the risk of harmful outcomes. We challenge researchers and practitioners to create a unifying and dynamic physiological model for each body system that can be continuously updated and mapped as knowledge is gained.

Intersection of mental health issues and Relative Energy Deficiency in Sport (REDs): a narrative review by a subgroup of the IOC consensus on REDs

Overall athlete health is a stated priority by the International Olympic Committee (IOC), yet it can be difficult for athletes to safely balance nutritional needs, training load, recovery, social interactions, expectations and other demands. The effect of energy intake and, especially, low energy availability (LEA) on athlete mental health, is understudied. In this narrative review, we examine research that has included psychological factors and mental health variables when investigating the effect of LEA, dieting/restrictive eating and Relative Energy Deficiency in Sport (REDs), since the 2018 IOC consensus statement on REDs. Based on currently available data, early psychological indicators associated with problematic LEA are mood changes, fatigue and psychological conflict. More severe mental health outcomes associated with REDs are reduced well-being, elevated anxiety, depressive symptoms and eating disorders. We propose a psychological model that helps structure how possible risk factors (eg, body dissatisfaction, environmental demands or increased training load) and moderating (eg, gender, sport) and/or potential mediating (eg, social climate, self-esteem) factors are associated with LEA and ultimately REDs. The current scientific literature underscores the importance of including mental health factors when screening for REDs and for developing a clinical approach to address the psychological sequelae of REDs once diagnosed. An interdisciplinary perspective is recommended. Lastly, and importantly, the athlete perspective urges clinicians to not underestimate the drive for success and denial of health consequences that athletes demonstrate when pursuing their sport goals.

Methodology for studying Relative Energy Deficiency in Sport (REDs): a narrative review by a subgroup of the International Olympic Committee (IOC) consensus on REDs

In the past decade, the study of relationships among nutrition, exercise and the effects on health and athletic performance, has substantially increased. The 2014 introduction of Relative Energy Deficiency in Sport (REDs) prompted sports scientists and clinicians to investigate these relationships in more populations and with more outcomes than had been previously pursued in mostly white, adolescent or young adult, female athletes. Much of the existing physiology and concepts, however, are either based on or extrapolated from limited studies, and the comparison of studies is hindered by the lack of standardised protocols. In this review, we have evaluated and outlined current best practice methodologies to study REDs in an attempt to guide future research.This includes an agreement on the definition of key terms, a summary of study designs with appropriate applications, descriptions of best practices for blood collection and assessment and a description of methods used to assess specific REDs sequelae, stratified as either Preferred, Used and Recommended or Potential Researchers can use the compiled information herein when planning studies to more consistently select the proper tools to investigate their domain of interest. Thus, the goal of this review is to standardise REDs research methods to strengthen future studies and improve REDs prevention, diagnosis and care.

The Influence of Energy Balance and Availability on Resting Metabolic Rate: Implications for Assessment and Future Research Directions

Resting metabolic rate (RMR) is a significant contributor to an individual's total energy expenditure. As such, RMR plays an important role in body weight regulation across populations ranging from inactive individuals to athletes. In addition, RMR may also be used to screen for low energy availability and energy deficiency in athletes, and thus may be useful in identifying individuals at risk for the deleterious consequences of chronic energy deficiency. Given its importance in both clinical and research settings within the fields of exercise physiology, dietetics, and sports medicine, the valid assessment of RMR is critical. However, factors including varying states of energy balance (both short- and long-term energy deficit or surplus), energy availability, and prior food intake or exercise may influence resulting RMR measures, potentially introducing error into observed values. The purpose of this review is to summarize the relationships between short- and long-term changes in energetic status and resulting RMR measures, consider these findings in the context of relevant recommendations for RMR assessment, and provide suggestions for future research.

Exogenous glucose oxidation during endurance exercise under low energy availability

The present study was conducted to determine the effect of endurance exercise under low energy availability (EA) on exogenous glucose oxidation during endurance exercise. Ten active males (21.4 ± 0.6 years, 170.4 ± 1.4 cm, 62.4 ± 1.5 kg, 21.5 ± 0.4 kg/m²) completed two trials, consisting of two consecutive days (days 1 and 2) of endurance training under low EA (19.9 ± 0.2 kcal/kg fat free mass [FFM]/day, LEA trial) or normal EA (46.4 ± 0.1 kcal/kg FFM/day, NEA trial). The order of these two trials was randomized with at least a 1-week interval between trials. As an endurance training, participants performed 60 min of treadmill running at 70% of maximal oxygen uptake (V˙O2max) during two consecutive days (on days 1 and 2). On day 1, the endurance training was performed with consumed individually manipulated meals. During the endurance exercise on day 2, exogenous glucose oxidation was evaluated using ¹³C-labeled glucose, and respiratory gas samples were collected. In addition, blood glucose and lactate concentrations were measured immediately after exercise on day 2. Body composition, blood parameters, and resting respiratory gas variables were evaluated under overnight fasting on days 1 and 2. Body weight was significantly reduced in the LEA trial on day2 (day1: 61.8 ± 1.4 kg, day 2: 61.3 ± 1.4 kg, P < 0.001). There were no significant differences between trials in ¹³C excretion (P = 0.33) and area under the curve during the 60 min of exercise (LEA trial: 40.4 ± 3.1 mmol•60min, NEA trial: 40.4 ± 3.1 mmol•60min, P = 0.99). However, the respiratory exchange ratio (RER, LEA trial: 0.88 ± 0.01, NEA trial: 0.90 ± 0.01) and carbohydrate oxidation (LEA trial: 120.1 ± 8.8 g, NEA trial: 136.8 ± 8.6 g) during endurance exercise showed significantly lower values in the LEA trial than in the NEA trial (P = 0.01 for RER and carbohydrate oxidation). Serum insulin and total ketone body concentrations were significantly changed after a day of endurance training under low EA (P = 0.04 for insulin, P < 0.01 for total ketone). In conclusion, low EA during endurance exercise reduced systemic carbohydrate oxidation; however, exogenous glucose oxidation (evaluated by ¹³C excretion) remained unchanged during exercise under low EA.

Energy availability and RED-S risk assessment among Kho-Kho players in India

Purpose

Energy availability (EA) is considered an important measure for athletes, particularly due to the possible health and performance outcomes defined under the RED-S. Low EA is reported to have far-reaching health consequences among female athletes, especially in weight-sensitive sport. However, it is less explored among male athletes, particularly in the traditional Indian tag sport called Kho-Kho. This cross-sectional observational study aimed to determine the prevalence of LEA and associated RED-S health and performance outcomes among Kho-Kho players.

Methods

Fifty-two male national-level Kho-Kho players aged 16-31 years were assessed for energy availability, bone mineral density (BMD), sleep quality, disordered eating, selected metabolic (hemoglobin, blood glucose, etc.) and performance outcomes (agility, speed, and power) as per RED-S risk assessment tool. Differences across the low EA (≤ 25 kcal/ kg fat-free mass) and Optimal EA (> 25 kcal/ kg fat-free mass) groups were evaluated using the Independent Samples t test and the chi-square test.

Results

Low EA among athletes was associated with lower z-scores for BMD, sleep quality and agility, compared to athletes with optimal EA. At least one moderate-to-high RED-S risk outcome was prevalent among 98% of the Kho-Kho players, irrespective of EA. Most athletes exhibited a lower EAT score and disordered eating outcomes, with no significant differences across groups.

Conclusion

The male Kho-Kho players showed a prevalence of low EA that can be due to higher training loads and unintentional under-eating, not related to an eating disorder. The players also exhibited higher RED-S risk outcomes; however, it was irrespective of low EA.