RED-S in Women: Symptoms, Risks & Recovery

If you’re an active woman dealing with irregular periods, stubborn fatigue, or injuries that keep coming back, you may be facing more than simple “overtraining.”
You could be experiencing RED-S: Relative Energy Deficiency in Sport, a condition that affects thousands of women and is still widely misunderstood.

RED-S happens when your body doesn’t have enough energy to cover both your training and your basic daily functions. And it’s more common than most people realise, not just in elite athletes, but in everyday women juggling busy lives, exercise, and nutrition that simply doesn’t meet their energy needs.

Table of Contents

What Is RED-S?

RED-S occurs when your energy intake is consistently lower than your energy output. It’s not solely related to eating disorders or extreme diets, it can affect anyone who unintentionally under-fuels while training regularly.

It replaces the older concept of the Female Athlete Triad because we now know RED-S impacts multiple body systems, and it affects people of all genders, not just female athletes.

Who’s at Risk?

You don’t have to be a full-time athlete, or look underweight to develop RED-S. You may be at risk if you:

Are a recreational runner or gym-goer
Have recently increased training intensity
Balance a demanding lifestyle with regular exercise
Follow a restrictive diet while staying active
Participate in sports that emphasise leanness (dance, gymnastics, distance running)

Many women with RED-S look “healthy” from the outside, making it easy to miss.

Common Symptoms of RED-S

RED-S can affect nearly every major system in your body.

Reproductive Health

Irregular or absent periods (amenorrhoea)
Difficulty conceiving
Low libido

Performance & Injury Risk

Decreased endurance or strength
Frequent injuries or stress fractures
Slow recovery
Persistent fatigue despite rest

Metabolic Signs

Feeling unusually cold
Low resting heart rate
Dizziness or fainting
Brittle nails or hair thinning

Psychological Changes

Irritability or mood swings
Anxiety or depression
Brain fog or trouble concentrating
Obsessive thoughts about food or exercise

Why Your Period Matters

Missing periods is never a sign of peak fitness.

In RED-S, the body produces less oestrogen because it is trying to conserve energy. Low oestrogen affects:

Bone density → leading to fractures and osteoporosis
Heart health
Immune function
Fertility – which may take time to recover even once periods return

Your menstrual cycle is a vital sign. If it stops, something is wrong.

The Long-Term Consequences of RED-S

Without treatment, RED-S can lead to:

Irreversible bone loss (especially dangerous in teens and women under 30)
Premature osteoporosis
Cardiovascular complications
Chronic hormonal imbalance
Metabolic disruption that complicates future weight management

These issues can persist for years if not properly addressed.

Why RED-S Goes Unrecognised

Sport and fitness culture often praises women for:

Having “discipline” with food
Pushing through exhaustion
Training every day
Celebrating the absence of periods as a sign of being “lean” or “fit”

But missing periods, constant fatigue, or frequent injuries are not normal.
They are warning signs that your body is under severe stress.

How RED-S Is Diagnosed

A proper assessment includes:

Comprehensive hormone testing (FSH, LH, oestradiol, thyroid, cortisol)
Bone health evaluation (DEXA scan if needed)
Nutritional and energy intake review
Training load assessment

This gives a full picture of whether your energy availability is adequate.

How RED-S Is Treated

Recovery focuses on restoring energy balance and supporting hormonal recovery. This may include:

Increasing calorie intake
Adjusting training intensity or frequency
Hormone replacement therapy where clinically appropriate
Addressing mindset, anxiety, or perfectionism around training or food
Regular monitoring of menstrual cycles and bone health

Recovery isn’t instant — it often takes 6–12 months, but full recovery is possible with the right support.

How The Female Health Doctor Clinic Can Help

At The Female Health Doctor Clinic, we understand the delicate relationship between exercise, hormones, nutrition, and stress. We offer:

Specialist hormone testing and interpretation
DEXA scans for bone health
Support for menstrual recovery and fertility
Referrals to sports nutritionists, physiotherapists, or mental health professionals where needed

You do not need to “work less”, you need the right balance to support both your fitness goals and your long-term health.

Your Health Comes First

Being strong, active, and motivated is a gift, but not if it costs you your hormonal health, bone strength, or fertility.

If you recognise any symptoms of RED-S, don’t put it off. Early support leads to better outcomes.

Ready to take the first step?
Book a consultation to discuss your symptoms, arrange specialist hormone testing, and start your personalised recovery plan.

Your body is speaking, let’s listen to it together.

RED-S Overview & Definitions

IOC Consensus Statement on RED-S (2014, updated 2018) — International Olympic Committee
Mountjoy M, et al. “IOC consensus statement on relative energy deficiency in sport (REDs).” Br J Sports Med: https://bjsm.bmj.com/content/57/17/1073.abstract
BMJ Review: https://bjsm.bmj.com/content/51/21/1570
“Relative Energy Deficiency in Sport (RED-S): A Review.”