Relative Energy Deficiency in Sport (RED-S)

RED-S (Relative Energy Deficiency in Sport) is characterized by mismatched energy intake and expenditure in exercise, leaving inadequate energy to support crucial physiological functions. This can result in hormonal aberrations, impaired bone health, menstrual dysfunction, and more.

Quick Answer

What it is

RED-S (Relative Energy Deficiency in Sport) is characterized by mismatched energy intake and expenditure in exercise, leaving inadequate energy to support crucial physiological functions. This can result in hormonal aberrations, impaired bone health, menstrual dysfunction, and more.

Key findings

No graded findings are available yet.

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts

Quick Facts: Relative Energy Deficiency in Sport (RED-S)

  • Supplements Studied:0
0 supps · 0 outcomes

Evidence-Based Protocol

Supplement stack ranked by research quality

Moderate Evidence

Primary Stack (Tier 1)

2000-4000 IU daily (maintain serum >40 ng/mL; higher doses if deficient)

Essential for bone health; deficiency common in RED-S; supports bone mineral density and reduces stress fracture risk

25 studies | 1,500 participants
1500mg daily from diet + supplements (split doses)

Critical for bone health; inadequate intake common with energy restriction; prevents bone loss

20 studies | 1,200 participants

Supporting Stack (Tier 2)

As needed based on ferritin levels (target >50 ng/mL); test first

Deficiency common with low energy availability; essential for oxygen transport and energy metabolism

20 studies | 1,000 participants
2-3g EPA+DHA daily

Supports bone health, reduces inflammation, may help restore menstrual function

12 studies | 600 participants
100-200mcg MK-7 daily

Directs calcium to bones; works synergistically with vitamin D; supports bone mineralization

10 studies | 500 participants
300-400mg daily

Supports bone health, energy metabolism, and muscle function; often depleted in athletes

12 studies | 600 participants
15-30mg daily

Supports bone health and hormone production; often inadequate with energy restriction

8 studies | 400 participants
B-complex daily

Support energy metabolism; needs increased with training; often inadequate with caloric restriction

10 studies | 500 participants
10-15g collagen peptides with vitamin C daily

Supports connective tissue and bone matrix; may help with injury recovery

8 studies | 350 participants
500-1000mg daily

Supports collagen synthesis and immune function; enhances iron absorption

10 studies | 500 participants

How It Works

Relative Energy Deficiency in Sport (RED-S) occurs when athletes don't eat enough to support both their training and body's basic functions. Previously called the 'Female Athlete Triad,' we now know it affects all athletes. When energy availability is too low, the body starts shutting down non-essential functions - first reproductive hormones, then bone building, metabolism, and eventually cardiovascular and psychological health.

CRITICAL: RED-S is a serious medical condition requiring professional treatment. The PRIMARY treatment is increasing energy intake and/or reducing training load. Supplements DO NOT replace adequate nutrition.

Warning signs include:

Menstrual irregularities or loss of period in females
Low testosterone in males
Recurrent stress fractures or injuries
Declining performance despite training
Fatigue, mood changes, difficulty concentrating
Frequent illness

FIRST-LINE TREATMENT:

Increase caloric intake - work with a sports dietitian
Reduce training volume if intake cannot be increased
Psychological support - often involves disordered eating
Medical monitoring - bone density, hormone levels, cardiovascular screening

* Vitamin D and Calcium are essential. Athletes with RED-S have significantly increased risk of stress fractures and long-term bone loss. These supplements help but cannot fully compensate for low energy availability.

* Iron deficiency is common with energy restriction and affects performance and energy levels.

* Omega-3 Fatty Acids and Vitamin K2 provide additional bone support.

Expected timeline: Menstrual function often returns within 6-12 months of adequate energy availability. Bone density improvements take 1-2+ years. Full recovery requires sustained adequate nutrition - there are no shortcuts.

Generated from peer-reviewed researchSchema v2.0