Relative Energy Deficiency in Sport (RED-S)

Are you unable to recover between training sessions? Experiencing severe wide-spread muscle ache/DOMS? As a female athlete, has your menstruation ever been affected by your training? These can all be signs of energy deficiencies and overtraining. Our blog explores what energy deficiency is, how to identify it and how to treat it.  

What is RED-S? 

Relative Energy Deficiency in Sport (or RED-S) is due to low energy availability in athletes. This means the fuel going into the body from food is less than the energy burnt during exercise. This energy balance should be at least equal and is additional to the normal calories consumed during the day. When energy input is at a deficit, RED-S can have significant impact on many body systems, affecting both injury risk and performance. 

RED-S used to be known as the ‘female athlete triad,’ terminology which is no longer used as it affects ALL athletes. The most well-known consequences of poor energy availability are bone stress injury and female athletes losing their period. These are both extreme consequences of RED-S, however there are much earlier signs and symptoms which are lesser known. 

Signs and Symptoms 

·      Poor sporting performance 

·      Inability to recovery between sessions

·      Poor wound healing 

·      Regular cold and flu sickness

·      Irregular/cessation of menstruation/periods (see below; ‘The female athlete’)

·      Poor bone health/osteopenia/bone stress response

·      Mood changes 

·      Iron deficiency 

·      Arrythmias (in severe cases)

Why does it matter? 

1.     Adverse effect on performance 

·      Quicker onset of fatigue from less energy available to skeletal muscles

·      Reduction in muscle strength/size due to impaired testosterone production and compromised neuromuscular control  

·      Impaired recovery increasing the risk of overtraining 

2.     Impact on health and wellbeing 

·      Increased the risk of chronic fatigue 

·      Low energy availability decreases the ability to heal from injury. Strains, sprains, cuts and bone injuries will take longer to heal

·      Impaired growth and development from inadequate cell turnover

The good news is most effects of RED-S are reversible if picked up early.

Athletes are often worried increasing food intake can result in weight gain. This is not the case for most athletes. Nutritionists and sports science professionals understand the energy demands of sport and ensure the balance between energy input and output is correct. 

The female athlete

1.     Menstruation 

If an athlete has low energy availability, their body is unable to produce normal levels of hormones. This can affect the menstrual cycle in female athletes. Periods may become irregular, or even cease altogether. Although the female menstrual cycle is variable between individuals, an individual’s cycle should be quite consistent. Irregularity or cessation of periods for longer than 6 months, or not getting a period by 16 years of age should be reviewed by a doctor. 

2.     Contraception 

Female athletes may be advised the oral contraceptive pill can treat symptoms and normalise their menstrual cycle. The combined pill produces a synthetic estrogen the body can not process and therefore does not assist with improving bone health. This can mask hormonal problems, without assisting in bone health. Athletes using contraception that contains estrogen may also be screened for risk factors of RED-S. Athletes using contraception that alters the normal production of a period (e.g. Mirena, Implanon) must also be monitored for RED-S symptoms.

How can physio help?

Physios can help review your training program and lifestyle to assess energy availability. If an athlete is at significant risk of RED-S, a Sports Physician should be involved to identify any hormonal/nutritional deficiencies and directly address them. This is commonly done through a blood test. 

After any nutritional deficits have been addressed, a physio can help modify training loads and aid with recovery techniques.

Who else can help? 

Sports doctor – Vital for initial diagnosis and hormonal/nutritional testing. Depending on severity, medical intervention may be needed (e.g. iron infusion)

Nutritionist – Eat the right food… and enough food, is vital for good energy availability   

Strength and conditioning coach – Clever programming results in efficient training and decreases the risk of overtraining.