Can Boys Get RED-S? Understanding Male Athlete Underfueling

December 18, 2025 •

4 min read

While traditionally associated with female athletes, research shows that between 15% and 70% of male athletes across various sports can be affected by Relative Energy Deficiency in Sport (RED-S). This syndrome, caused by a mismatch between energy intake and energy expenditure, can have severe health and performance consequences for boys and men.

Quick Summary

This article explores how Relative Energy Deficiency in Sport affects male athletes, detailing the specific symptoms like low testosterone and poor bone health. It discusses risk factors, provides information on accurate diagnosis, and outlines a comprehensive, multidisciplinary treatment approach for recovery and long-term health.

Key Points

Prevalence in Males: Yes, boys can get RED-S, a syndrome caused by insufficient calorie intake relative to energy expenditure, with prevalence rates as high as 70% in some male athlete populations.
Absence of Key Sign: RED-S is often overlooked in males because they lack the distinct symptom of amenorrhea (loss of menstruation) seen in females, leading to underdiagnosis.
Hormonal Consequences: For male athletes, low energy availability can lead to significant suppression of testosterone, impacting reproductive function, libido, and mood.
Bone Health Risks: Chronic underfueling impairs bone mineral density in adolescent boys, a critical period for bone mass accrual, increasing the risk of stress fractures and lifelong osteoporosis.
Multisystemic Effects: Beyond hormones and bones, RED-S can cause chronic fatigue, impaired immunity, mood changes (anxiety, depression), and gastrointestinal issues in male athletes.
Team-Based Treatment: Effective treatment requires a multidisciplinary team, including a sports physician, dietitian, and mental health professional, to address the physical and psychological aspects of the condition.

Yes, Boys Can Absolutely Get RED-S

The misconception that Relative Energy Deficiency in Sport (RED-S) only affects female athletes stems from its predecessor, the "Female Athlete Triad". However, the International Olympic Committee renamed the condition in 2014 to reflect its broader impact on all genders. The core issue is low energy availability (LEA), a chronic state where an athlete consumes fewer calories than their body needs for training, daily life, and normal physiological function. While the red flag symptom of menstrual dysfunction is absent, male athletes experience their own set of serious health and performance issues as a result of prolonged underfueling.

Why RED-S in Males Often Goes Undiagnosed

One of the biggest challenges for male athletes is the lack of an obvious and culturally recognized symptom like the loss of a menstrual period. Athletes, parents, and even some healthcare professionals may mistakenly attribute symptoms like fatigue or moodiness to intense training or overtraining, delaying a proper diagnosis. The 'toughen up' culture in many sports can further discourage male athletes from reporting subtle but significant health changes. Additionally, for weight-sensitive sports, the desire for a low body weight is often praised, normalizing the dangerous underfueling behavior that leads to RED-S.

Systemic Health Consequences in Male Athletes

When a boy's body is in a state of chronic energy deficit, it must conserve energy by down-regulating non-essential functions to survive. This impacts multiple systems, leading to a cascade of negative health outcomes.

Endocrine System: Low energy availability suppresses the hypothalamic-pituitary-gonadal axis in males, leading to a significant drop in testosterone levels. This can result in decreased libido, poor reproductive function, and changes in mood and energy.
Skeletal System: Testosterone is crucial for bone formation, with male athletes acquiring a large percentage of their peak bone mass during adolescence. Low testosterone levels, combined with insufficient nutrient intake, can impair this process, leading to low bone mineral density, a higher risk of stress fractures, and potentially irreversible long-term osteoporosis.
Immune System: Chronic underfueling weakens the immune system, leaving athletes more susceptible to frequent illnesses and infections like colds and flu.
Metabolic Function: The body's resting metabolic rate slows down to conserve energy, making it difficult for the athlete to meet their energy needs even at rest. This can lead to persistent fatigue and a reduced ability to adapt to training.
Psychological Health: The hormonal and metabolic disruptions caused by RED-S contribute to mood swings, anxiety, depression, and irritability. A preoccupation with food and weight, sometimes manifesting as disordered eating, is also common.

Recognizing the Symptoms

Identifying RED-S in male athletes requires a high degree of awareness from the athlete, parents, coaches, and medical professionals. Key indicators include:

Performance Decline: A drop in performance, strength, endurance, or coordination that cannot be explained by normal training variation.
Frequent Injury: An increased incidence of stress fractures, pulled muscles, or overuse injuries with slower than normal healing.
Persistent Fatigue: Chronic and unexplained tiredness, lethargy, or poor sleep quality.
Weight Changes: Unexplained weight loss or an inability to gain muscle mass despite heavy training.
Hormonal Changes: A noticeably low sex drive or, in adolescents, delayed or stunted growth and puberty.
Mood Changes: Increased irritability, anxiety, or depressive symptoms.

Treatment and Prevention Strategies for Male RED-S

Effective management of RED-S involves a comprehensive and collaborative team approach. The goal is to correct the energy deficit by increasing energy intake and, in some cases, reducing energy expenditure through a modified training plan.


Treatment Component	Focus Area	Specific Actions for Male Athletes
Nutritional Counseling	Correcting low energy availability (LEA)	Work with a sports dietitian to develop a personalized nutrition plan, emphasizing adequate caloric and nutrient intake to meet training demands. Address any disordered eating patterns.
Medical Intervention	Managing physiological consequences	A sports physician should monitor hormone levels, particularly testosterone, and bone health using DXA scans. Calcium and Vitamin D supplementation may be necessary.
Psychological Support	Addressing mental health issues	Work with a mental health professional to address any underlying anxiety, depression, or body image concerns. This is especially critical if disordered eating behaviors are present.
Adjusted Training Plan	Allowing for physical recovery	A physiotherapist or sports coach should help create a temporary, reduced training schedule to allow the body to recover and restore energy balance. Modify load to prevent further injury.

Prevention is key and centers on education for athletes, parents, and coaches about the risks of underfueling. Emphasizing health over an extremely lean body type and promoting a positive, realistic body image are crucial steps. Creating an environment where athletes feel safe discussing nutritional and body image issues can prevent RED-S from ever taking hold. It is vital to remember that prioritizing health ultimately leads to sustained, high-level athletic performance.

Conclusion

Can boys get RED-S? The definitive answer is yes. This serious condition, born from prolonged low energy availability, affects male athletes across all sports and levels. While lacking the clear warning sign of menstrual dysfunction, males still exhibit a range of physical and psychological symptoms, including low testosterone, poor bone health, and mood disturbances. Early recognition and a multidisciplinary treatment approach focusing on restoring energy balance are critical for preventing long-term, and potentially irreversible, health consequences. Promoting a culture of proper fueling and health over excessive leanness is essential for the well-being of all athletes.

Frequently Asked Questions

The main cause is a state of low energy availability (LEA), where the athlete's energy intake from food is insufficient to cover their energy expenditure from both daily life and training over a prolonged period.

In male athletes, RED-S leads to suppressed testosterone levels. This can result in reduced libido, decreased sperm count, and impaired reproductive function.

Yes, if left untreated, RED-S can cause serious long-term consequences, including irreversible low bone mineral density (osteoporosis), chronic hormonal imbalances, and potential heart problems.

Male athletes with RED-S may experience mood swings, anxiety, depression, increased irritability, difficulty concentrating, and a preoccupation with weight or eating.

Diagnosis involves a comprehensive medical and sports history, physical examination, and potentially blood tests to check hormone levels and imaging to assess bone density. It is diagnosed based on a constellation of symptoms.

RED-S is more prevalent in sports that emphasize leanness or have weight categories. This includes endurance sports (running, cycling), aesthetic sports (diving, gymnastics), and combat sports (wrestling, boxing).

RED-S is a physiological syndrome caused by low energy availability. While it is not an eating disorder itself, it can occur alongside or be caused by disordered eating behaviors. Treatment strategies depend on whether the energy deficit was intentional or unintentional.