Low Energy Availability Research Articles

From semi-starvation to the stage: a case report on indicators of low energy availability in a drug-free bodybuilder during contest preparation and peak week

Natural bodybuilding competitions involve periods of low energy availability (EA) combined with resistance training and high-protein diets to achieve extreme leanness. This study tracked a drug-free bodybuilder adopting evidence-based nutrition practices during 18 weeks of contest preparation. We measured endocrine function, resting energy expenditure, respiratory exchange ratio, body composition, resting heart rate, oral temperature, mood, and strength performance. Endocrine function was remeasured after 2 days of energy repletion. From baseline to week 18, free triiodothyronine (T3) and total testosterone (TT) fell into clinically low (2.7 pmol/L−1) and sub-clinically low (9.1 nmol/L−1) ranges. Resting energy expenditure decreased by −519 kcal (REEratio 0.78), and respiratory exchange ratio decreased from 0.95 to 0.85. Body mass reduced by −5.1 kg, with a sum of eight skinfold loss of −15.7 mm. Correlations were observed between body mass and decreases in oral temperature (r = 0.674, p = 0.002) and resting heart rate (r = 0.560, p = 0.016). Mood remained stable until the final 2 weeks and relative one-repetition maximum decreased in the squat (−5.4%), bench (−2.6%), and deadlift (−3.6%). Following 2 days of modest energy repletion, free T3 increased (18.5%), returning to sub-clinically low values (3.2 pmol/L−1), whereas TT fell (−20.9%), reaching clinically low values (7.2 nmol/L−1). These results offer insight into the dynamics of T3 and TT following a short-term period of modest energy repletion and further information on indicators of low EA during chronic energy restriction.

The whole-body and skeletal muscle metabolic response to 14 days of highly controlled low energy availability in endurance-trained females.

This study investigated the effects of 14 days low energy availability (LEA) versus optimal energy availability (OEA) in endurance-trained females on substrate utilization, insulin sensitivity, and skeletal muscle mitochondrial oxidative capacity; and the impact of metabolic changes on exercise performance. Twelve endurance-trained females (V̇O2max 55.2 ± 5.1 mL × min-1 × kg-1) completed two 14-day randomized, blinded, cross-over, controlled dietary interventions: (1) OEA (51.9 ± 2.0 kcal × kg fat-free mass (FFM)-1 × day-1) and (2) LEA (22.3 ± 1.5 kcal × kg FFM-1 × day-1), followed by 3 days OEA. Participants maintained their exercise training volume during both interventions (approx. 8 h × week-1 at 79% heart rate max). Skeletal muscle mitochondrial respiratory capacity, glycogen, and maximal activity of CS, HAD, and PFK were unaltered with LEA. 20-min time trial endurance performance was impaired by 7.8% (Δ -16.8 W, 95% CI: -23.3 to -10.4, p < .001) which persisted following 3 days refueling post-LEA (p < .001). Fat utilization was increased post-LEA as evidenced by: (1) 99.4% (p < .001) increase in resting plasma free fatty acids (FFA); (2) 270% (p = .007) larger reduction in FFA in response to acute exercise; and (3) 28.2% (p = .015) increase in resting fat oxidation which persisted during submaximal exercise (p < .001). These responses were reversed with 3 days refueling. Daily glucose control (via CGM), HOMA-IR, HOMA-β, were unaffected by LEA. Skeletal muscle O2 utilization and carbohydrate availability were not limiting factors for aerobic exercise capacity and performance; therefore, whether LEA per se affects aspects of training quality/recovery requires investigation.

Boston Marathon athlete performance outcomes and intra-event medical encounter risk associated with low energy availability indicators

ObjectiveTo determine the association between survey-based self-reported problematic low energy availability indicators (LEA-I) and race performance and intra-event medical encounters during the Boston Marathon.Methods1030 runners who were registered for the...

Assessing Energy Availability and Glucose Dynamics in Adolescent Cyclists: Implications for Nutritional Interventions During the Competitive Season

Background: The risk of developing a state of low energy availability (LEA) (&lt;30 kcals/kg free-fat mass) in endurance athletes is known and recommendations for nutrition are available. However, information on male adolescent cyclists and the influence of hot temperatures is limited. Objectives: The aim of this study was to investigate the impact on energy availability of two 4-day nutritional intervention strategies: (1) supplementary carbohydrate (CHO) intake during exercise and (2) designing and implementing individual nutritional interventions. Methods: Each intervention was preceded by a 4-day basal assessment. Eight competitive male junior road cyclists (aged 16–17 years) were investigated using a 4-day diet and activity records, alongside bioelectric impedance analysis. Their real-time power output, interstitial glucose, and temperature were recorded via sensors and a bike computer. Their energy intake (EI) was estimated from daily, self-reported food diaries. Results: Overall, 100% and 71% of the cyclists were in a state of LEA during the baseline assessment of the supplementary CHO and nutritional interventions, respectively. LEA prevalence, not modified by supplementary CHO intake alone (from 100% to 87%, ns), was markedly reduced by the individual nutritional intervention (from 71% to 14%, p &lt; 0.05). When considering all the data as a whole, LEA was positively influenced by the training load (OR 1.06; 95% Cl 1.03 to 1.09) and free-fat mass (OR 1.46; 1.04 to 2.04) and was negatively affected by EI (OR 0.994; 0.991 to 0.997). A hot environment (air temperature) failed to influence the LEA or glucose dynamics. Conclusions: the nutritional intervention, but not the supplementary CHO intake, markedly reduced the prevalence of LEA in adolescents, who often fail to match their energy expenditure with their energy intake during the competitive season. Nutritional education is essential for adolescent endurance cycling teams.

La pratique du cyclisme de haut niveau impacte-t-elle la masse osseuse ?

Background : Elite cyclists may be at risk for osteopenia. Many factors can lead to bone loss in cycling, including low energy availability, low grade of inflammation, and a weak mechanical osteogenic stimulus. Thus we wanted to assess bone health in one elite team of professional cyclists, and to identify correlations between BMD and potential risks factors.Methods : Thirty-three adult male cyclists were recruited from one international team. Total body, hip femur and lumbar spine BMD had been measured by DXA and was compared to standard values for a healthy population of same age and sex. Training characteristics, morphometrics, body lean mass, fat mass, history, medication and results of recent blood and stool analysis were collected and compared between the cyclists having low BMD and those with unaltered BMD. Univariate and multivariate correlation analyses were carried out to identify predictive factors for low BMD.Results : Twenty-one (64%) out of 33 cyclists presented a Z score < -1 at one site, and five of them (15%) had densitometric osteoporosis. Lumbar spine was involved every time ‘Z score = -b 1,23 +/- 0,94). Age, history, and training characteristics were significantly and negatively linked to BMD. After multiple regression, no variable had an independent correlation with BMD. No correlation was found with biomarkers or with training characteristics.Conclusion : Our study shows a worrying proposition of low bone mass in our population of young male and otherwise healthy cyclists. Low energy availability, as the missing point of our study, might be the main causal factor. Great attention should be paid in bone status in elite cyclists of any age.

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

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

Female Athlete Triad: Understanding the Interrelationship between Energy Availability, Menstrual Function, and Bone Health

The Female Athlete Triad (FAT) is a complex medical condition characterized by three interrelated components: low energy availability (EA) with or without disordered eating, menstrual dysfunction, and decreased bone mineral density (BMD). This syndrome is particularly prevalent among female athletes who engage in sports that prioritize leanness, endurance, and aesthetic performance, such as gymnastics, dance, and long-distance running. Prolonged exposure to inadequate caloric intake relative to energy expenditure can disrupt hormonal regulation, leading to irregular or absent menstrual cycles (amenorrhea) and compromising bone health. This cross-sectional study aims to investigate the prevalence and impact of low EA on menstrual function and BMD among 180 female athletes aged 18-30 years. Participants were divided into three menstrual status categories: eumenorrhea, oligomenorrhea, and amenorrhea. The study also categorized athletes into sports groups (aesthetic, endurance, and power sports) to identify patterns across different disciplines. Data collection included dietary intake records, exercise logs, menstrual history questionnaires, and DEXA scans to measure BMD at the lumbar spine and hip. Results indicate that 67% of participants exhibited low EA (&lt; 30 kcal/kgFFM/day), which was significantly associated with menstrual dysfunction (p &lt; 0.001). Among participants, 25% reported oligomenorrhea (irregular cycles), and another 25% experienced amenorrhea (absence of menstruation for more than three months). BMD analysis revealed that 30% of the athletes had osteopenia, while 5% were diagnosed with osteoporosis, highlighting the long-term risks associated with chronic low EA and menstrual irregularities. Notably, athletes engaged in aesthetic sports had the highest prevalence of low EA (80%) and menstrual dysfunction (45%), followed closely by those in endurance sports. These findings underscore the urgent need for targeted interventions to promote energy balance, safeguard reproductive health, and prevent bone deterioration among female athletes. Educational programs focusing on nutritional counseling, regular monitoring of menstrual health, and multidisciplinary care involving coaches, sports dietitians, and healthcare providers are essential to mitigate the risks of the Female Athlete Triad. Future research should further explore psychological factors influencing energy availability, including body image concerns and disordered eating patterns, to develop comprehensive prevention strategies.

Low energy availability surrogates are associated with Relative Energy Deficiency in Sport outcomes in male athletes

ObjectivesTo determine the association between surrogates of low energy availability (EA) and proposed health and performance outcomes of Relative Energy Deficiency in Sport (REDs) in a clinical sample of adolescent...

Energy Availability and Body Composition in Professional Athletes: Two Sides of the Same Coin

Background/Objectives: Energy availability (EA) is essential for maintaining physiological functions, significantly influencing athletes’ health and performance. Nutritional behaviors, however, vary across sports. This study aims to assess EA levels in athletes from different disciplines, focusing on the relationship between EA and body composition in endurance athletes compared to rugby players. Methods: This study involved 18 endurance athletes (15 men, 3 women) and 36 rugby players (all men). Data were gathered through interviews, questionnaires, and bioimpedance analysis. Energy intake (EI) was measured with a 24 h dietary recall, and exercise energy expenditure (EEE) was calculated using the IPAQ questionnaire. EA was calculated as EA = (EI − EEE)/fat-free mass (FFM), with results categorized into clinical, subclinical, and optimal ranges. Results: The endurance group had a lower average FFM (57.81 kg) compared to the rugby players (67.61 kg). EA was also significantly lower in endurance athletes (11.72 kcal/kg FFM) than in rugby players (35.44 kcal/kg FFM). Endurance athletes showed more restrictive nutritional behavior with lower EI and higher EEE, but both groups maintained body composition within normal ranges. Conclusions: Endurance athletes exhibit greater nutritional restrictions compared to rugby players, though their body composition remains healthy. Further research is required to investigate the long-term effects of low EA on performance, injury risk, and potential impairment when EA falls below the optimal threshold of 45 kcal/kg FFM/day.

Low Energy Availability Risk Is Associated with Anxiety in Female Collegiate Athletes.

This study investigated the association between the risk of low energy availability, disordered eating, and anxiety in collegiate female athletes. Female athletes (n = 115) completed questionnaires that assessed disordered eating (Disordered Eating Screen for Athletes, DESA-6; and the Eating Disorder Examination Questionnaire Short, EDE-QS), anxiety (Generalized Anxiety Disorder-7) and the risk of low energy availability (Low Energy Availability in Females Questionnaire; LEAF-Q). The athletes were 19.9 ± 0.1 years old and presented with no anxiety (14.8%), mild (33.0%), moderate (24.3%), and severe (27.8%) anxiety. The EDE-QS scores revealed that 22.6% of the participants had a high risk of an eating disorder, while the DESA-6 scores revealed that 31.3% of the participants scored positive for a risk of disordered eating. The LEAF-Q total scores revealed that 68.7% of the participants were at risk of low energy availability. Increased GAD-7 scores were associated (p < 0.001) with measures of disordered eating (EDE-QS and DESA-6) and the risk of low energy availability (LEAF-Q total score). Non-parametric partial correlations demonstrated that anxiety (increased GAD-7 scores) correlated with the risk of low energy availability (increased LEAF-Q total scores) while controlling for eating disorder scores (EDE-QS) (r (112) = 0.353, p < 0.001), or while controlling for the risk of disordered eating (DESA-6 scores) (r (112) = 0.349, p < 0.001). In female collegiate athletes, both disordered eating and the risk of low energy availability were positively associated with increased anxiety.

Prevalence of physiological and perceptual markers of low energy availability in male academy football players: a study protocol for a cross-sectional study

Low energy availability (LEA) is a core feature of the female athlete triad and relative energy deficiency in sport (REDs). LEA underpins multiple adverse health and performance outcomes in various...

Low Energy Availability, Menstrual Status, And Skeletal Health In Sportswomen

Low Energy Availability, Menstrual Status, And Skeletal Health In Sportswomen

Bone Stress Injuries, Risk Of Low Energy Availability And Exercise Dependence In Female Trail Runners

Bone Stress Injuries, Risk Of Low Energy Availability And Exercise Dependence In Female Trail Runners

Low Energy Availability Surrogates Are Associated With Relative Energy Deficiency In Sport Outcomes In Male Athletes

Low Energy Availability Surrogates Are Associated With Relative Energy Deficiency In Sport Outcomes In Male Athletes

Proportion and Characteristics of Low Energy Availability in Elite Female Dancers at Jakarta X Dance School

Proportion and Characteristics of Low Energy Availability in Elite Female Dancers at Jakarta X Dance School

Low Energy Availability Alters Metabolome With And Without Daily Exercise

Low Energy Availability Alters Metabolome With And Without Daily Exercise

Changes In Running Economy And Substrate Utilization During Acute Low Energy Availability

Changes In Running Economy And Substrate Utilization During Acute Low Energy Availability

Multiple Stress Fractures Higher In Female Recreational Runners At Risk Of Low Energy Availability

Multiple Stress Fractures Higher In Female Recreational Runners At Risk Of Low Energy Availability

The Association Of Low Energy Availability Knowledge And Risk In Female Track And Field Athletes

The Association Of Low Energy Availability Knowledge And Risk In Female Track And Field Athletes

Examination Of Low Energy Availability And Bone Health In Endurance Trained Runners

Examination Of Low Energy Availability And Bone Health In Endurance Trained Runners