RED-S: what I wish all athletes knew.

Share this Blog Post


I’ve been around athletes my entire life. From competing as a junior athlete and then as a young adult on the national athletic circuit in Australia, to now as a clinical nutritionist assisting athletes to achieve optimal performance: I’m all too familiar with health and peak performance. A common issue I’ve seen many clients and training partners battle with over the years is RED-S or restricted energy deficit in sport.

According to the IOC Consensus, the most common performance and health repercussions of RED-S include:

  • Increased injury risk
  • Decreased muscle strength
  • Decreased endurance performance
  • Irritability
  • Depression
  • Lack of concentration and/or coordination
  • Impaired judgement
  • Reduced thyroid function 
  • Reduced metabolism
  • Low testosterone
  • Reduced immunity


Awareness and investigation often present after the diagnosis of a stress fracture or loss of periods (in female athletes). It’s important to note, that being placed on the oral contraceptive pill doesn’t solve this problem: it simply masks the fact that it exists (to a degree). In female athletes, despite the loss of menstrual function being a key indicator of the female athlete triad and insufficient energy intake, it has become evident that disordered eating patterns can be present with or without alteration to menstrual function. Hence using this as a clinical diagnostic can be missing a huge subset of the population needing assistance. For male athletes, RED-S can go undiagnosed for years. But changes to mental health are often the first sign.

Furthermore, whilst stress fractures are a key indicator of low bone density, they are not always a sign of poor nutrition. Some athletes are not biomechanically robust, nor are their training programs designed to effectively allow for adaptation. We mustn’t assume any one factor to blame without properly assessing the full picture.

So why is RED-S so common?

Ever heard the sayings “All or nothing”? “No pain, no gain”? These phrases are all too common in the sporting context. And yet, both mislead many athletes into an unnecessary pursuit of pain, suffering & restriction. Quite often, this mindset transfers out of the training arena, and into the kitchen. Athletes are at a higher risk than the general population to develop disordered eating patterns.  As a result, an athlete can very quickly spiral into a host of health and performance obstacles, including the female athlete triad, psychological disturbances, injury and illnesses.

The saddest part about this story, is whilst it is extremely common, total restriction is by no means the catalyst for high performance. In fact, what I’ve seen many a time in both clinical practice, and through training partners: is that once you properly nourish and support your body, true performance gains are acquired. Even when you think you need to drop or ‘make’ weight, ensuring your body is consistently well fed is one of the keys to sustainable, healthy weight management for athletes. My goal as a health practitioner is for you to shift focus from quantity of calories to quality of foods consumed. This is not only going to support a healthier mindset around food, but also assist performance and long-term health.

If you feel you or one of your athletes may be at risk of having the female athlete triad, be sure to reach out to your team of health practitioners. Working collaboratively with your nutritionist, GP, psychologist or counsellor and musculoskeletal practitioner (such as a physio) is important for both optimal health and performance outcomes.

Start Your better

Health Journey

Want more personalised advice on what to eat to support YOUR health? Get in touch with us today and book a nutritional medicine appointment.

LSS Nutrition Blogs

Continue Reading