Are you putting enough fuel in your tank? Relative Energy Deficiency in Sport (RED-S)

Dom Ryan  / 2 Min Read / Nutrition.


When you think of the “ideal” body type for running, what do you think of?

The most common answer I get is “lean and skinny” …. And this answer drives me WILD! The “ideal” body type misconception is one of the most dangerous in our sport. In fact, the lean and skinny body type is actually unhealthy for many people (if not most, unless you are genetically gifted!). Runners attempting to achieve this physique may inflict on themselves many short and long-term health consequences.

Relative Energy Deficiency in Sport (RED-S) is the term used to describe when the body is under fuelled to perform training. RED-S not only impacts performance but also results in insufficient energy to maintain optimal health.

Think of your body as having 3 buckets of energy.

-       The Health Bucket

-       The Everyday Activities Bucket

-       The Exercise Bucket          

To thrive, the aim is to eat enough to keep all three buckets full, so you can train to your fullest while maintaining enough energy for everyday life and also maintain a state of good health. However, there are many reasons why runners might not eat enough. It may be that they are intentionally trying to achieve a certain physique by restricting calories. It may be due to a busy lifestyle and simply forgetting to eat lunch at work or skipping breakfast in the morning. Or it may be because they fail to understand the importance of fuelling adequately before, after and during training. Neglecting to fluctuate their intake based on training load.

Whatever the cause, when you don’t eat enough to fill the three buckets, your body starts to drain energy from them. When the ‘Exercise Bucket’ isn’t full, you may notice impacts on your training; such as being unable to reach peak performance, taking longer to recover between sessions and reoccurring injuries or niggles. When the ‘Everyday Activities Bucket’ isn’t full, you begin to notice your daily life being impacted; like becoming more irritable and having less energy to play with the kids, decreased concentration at work, feeling generally flat and having a low mood. And when the ‘Health Bucket’ begins to drain, this is when things can turn really nasty. A range of short and long term health issues can result…including:

●      Low bone mineral density, osteoporosis or stress fractures

●      Weight loss or low body weight

●      Periods stopping or becoming irregular

●      Fertility issues (short and long term)

●      Poor immune system and recurrent illnesses e.g. colds and flu’s

●      Mood fluctuations

●      Iron deficiency

●      Heart abnormalities

Image Via Unsplash : Anna Pelze

Image Via Unsplash : Anna Pelze

Thankfully most of the effects of RED-S are reversible if diagnosed and treated early. Treatment often comes down to two options:

1 – Increase energy intake

2 – Significantly decrease exercise

Let’s be honest though, if you’re reading this article and are an avid runner, then I don’t think you’re going to opt for becoming an overnight couch potato! So, increasing energy and protein intake to support exercise and recovery are the keys. For bone health, it’s also important to get enough calcium (such as dairy products, fortified plant-based milks and sardines/canned salmon with edible bones) and Vitamin D (hello sunshine!!!).

If you suffer from RED-S you may be thinking – “Heck, does this mean I have to put on weight?” Well, not necessarily! Research shows that below a certain body weight for height ratio, it’s difficult to achieve bone and hormonal health. So, in some cases, weight gain is an absolute must! However, as RED-S significantly reduces resting metabolic rate, increased energy availability leads to increasing the resting metabolic rate which may consequently mean that your weight doesn’t change much.

The best way to treat RED-S is ensure fuelling is targeted around training … Think of your training as being sandwiched between good nutrition. And when I say, “good nutrition”, I mean good nutrition for YOU - an athlete - the higher carbohydrate, higher protein, higher calorie stuff! Food should provide fuel for work and also nutrition for recovery. Remember that healthy eating for an athlete (professional OR recreational) is far different from the healthy eating guidelines recommended for the general population. Your diet should be personalised to your individual training and lifestyle.

Image Via Unsplash : KAFFEE MEISTER

Finally, it’s important to note that in some cases athletes may strive to achieve a specific body composition for a key competition or race. This may be done in a way that minimises risk with careful planning based on the athlete’s unique requirements, training program and periodised at specific times. However, the year-round pursuit of leanness via calorie restriction and high training volume not only impairs training gains and performance, but also increases risk of short- and long-term health complications.

So instead of focusing on eating to achieve a certain body composition, focus on fuelling for training and performance. And next time you’re pondering the question “What is the ideal body type for running?” look in the mirror. Have you got a body? Can you run?... Great! Then the ideal running body is YOURS. Celebrate it, be grateful for it, and fuel it well as your vehicle on this great adventure of life!

If you think you may be affected by RED-S or want more information on how to fuel your training correctly chat with a registered Sports Dietitian for more advice.


Author Profile

Dominque Ryan - Sunshine Coast based Ultra-runner + Dietitian.

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