When I started running, I focused on nothing but performing at my absolute best. And it was this desire for improved performance that was the initial motivation for making changes to my diet as I thought they would help me run better.

But somewhere along the way, my reason changed. It became about how those dietary changes would make me ‘look’ like a runner compared to my fellow competitors, instead of about how fast I could be.

I began to make choices that I knew deep down weren’t best for me or my performance. I stopped listening to my body’s hunger cues, and decided for myself what and when I could eat. I would refuse to give my body food when it used every physical sign that it could to tell me that it needed fuel. My 'sweet tooth' became insatiable as my body turned to desperate measures to ask for more calories. 

My running continued to improve, but behind the scenes, things began to crumble. I lost my period, couldn’t sleep, was irritable, and often angry. I was controlling around food, dictating what everyone around me could eat, and I was always tired and always cold...

RED-S warning signs

In March 2016, eight years after I first lost my period, I reached my highest goal when representing Great Britain and Northern Ireland in a World Championship. A month later, I ran another big PR at the London Marathon. Less than a year later, I quit running, not sure if I would ever run a step again. I simply couldn’t take it anymore and I hated everything about running…other than the finish line when it was all over.

I had symptoms of Relative Energy Deficiency in Sport (RED-S) during those nine years, but they were easy to dismiss. Now, I can look back and recognise those symptoms, as well as see the performance gains that I left on the table by not fueling properly. I have to live with the fact that I could have been much faster had I listened to my body instead of my comparative tendencies.

RED-S is more common than most runners think. It can either be intentional, as it was for me, or it can be unintentional. Either way, it can wreak havoc on a body, and maybe even, as in my case, leave the sport-loving person in a place where they have lost all joy and passion for the very thing they cared about.

Beyond the immediate physical setbacks, I learned that researchers weren't totally sure what the long-term effects of RED-S were, and I’m still discovering how those may have impacted me. As I prepare for surgery on my Achilles in a few weeks, I can’t help but wonder how much of the groundwork for the damage was done during those years of running under-fueled.

When I reflect on my time with RED-S, as well as the recovery period, I realise how much I have learned. I like to believe that I have helped many others to consider listening to their bodies instead of what a number on a scale says or the media bombarding us with messages of what “fast” looks like.

My 9 lessons

1. Your heart rate may be telling you the truth

One important method that experts in this area will use is to test your heart rate from rest to walking across the room. While bradycardia (low heart rate) is often celebrated in endurance sports, heart rates less than 30 beats per minute can also be an indicator of an eating disorder. The way my heart rate jumped significantly when getting up off the couch to walk across the room was a warning sign for me.

2. Don’t ignore your symptoms

Irritability, fatigue, insomnia, and regular gastrointestinal distress are things we can easily write off. It’s easy to claim that your period is missing because of stress, your testosterone levels are low because of training, and you’re feeling cold, because, well, it’s winter, right? 

But those symptoms are signs from our body that something isn’t right, and just because you have a one-day period every 40 days doesn’t mean you’re fueling well enough. Your body has its own way of letting you know that it is not okay, and if in doubt, speak to a registered dietitian to make sure you’re fueling for performance, as well as for your health.

3. Listen to your body

Deep down, I knew I wasn’t listening to my body when I started making rules like, “you can eat whatever you want if you have run more than 15 miles today” or, “I know you’re hungry, but dinner is in a few hours, so you can wait.” 

I wasn’t in a good place when I would plan my day around what I was going to have for dinner. I would save over half of what I thought my daily calories should be for the evening, restricting myself earlier knowing that I would binge later. I would look up restaurants long before I was going and decide exactly what I would order, then plan accordingly to make sure I didn’t go over what I had arbitrarily considered to be acceptable calories for the day.

4. No food is bad food

I found that when I denied myself a certain food or food group, I often craved it more. I’d tell myself that I can’t have a warm, freshly baked cookie at lunch, only to end up thinking about it all day, and then proceeding to eat an entire sleeve of Oreos later. But, it still didn’t fill the void because what I really wanted was that warm cookie. Instead, I felt shame, pain and numb.

It’s better to have those foods that you want, rather than labelling something as “bad” and making yourself miserable as you obsess about it. Of course we can say, “well, if I ate what I wanted every time, I would never touch a vegetable,” but the beautiful thing about our bodies is that it will crave those things that it needs. If we’re satisfied through allowing ourselves the things we want, it frees up the rest of our fueling choices to make decisions that take care of our health.

5. Fuel properly during your races

I only learned this one since I started working with Precision Fuel & Hydration last year. When I look back on my running performances and the fuel I was taking in during my marathons and half marathons, it was nowhere close to what I needed. 

I was leaving time on the table when I could have performed better in championships with a better race nutrition strategy. If you haven’t already, check out the Fuel & Hydration Planner. I wish I had access to it when I was running at an elite level.

6. Focus on your own work

I used to stand on the start line, looking around at the other elite athletes, wondering why my body didn’t look like theirs and what I could do to make it look that way. Now I understand that my body was never going to look like theirs because my body is exactly that, my body! 

We all have our own beautiful, perfectly imperfect genetic mix that determines what our shape is, and trying to squeeze into someone else's mold is only going to leave us at a disadvantage, mentally and physically. 

7. When to seek help

People tried to talk to me about this by telling me that I had a problem. I knew that they were concerned about my habits and health, but I refused to listen, pushing away the feelings that they might be right. 

That’s why, when I became vocal about RED-S awareness, I knew that I had to speak in a way that was not confrontational or aggressive, but gentle and understanding, led by compassion. I get it. If you read these words and felt a knot in your stomach, know that you’re not alone, and you have nothing to be ashamed of. Seeking out a registered dietitian in your area and seeing a mental health professional are hard steps to take and require bravery, but they will lead to both a better life and performance.

8. Recovery is achievable

I remember when people would say to me that they forgot to eat, my eyebrows would raise and I would have to resist the urge to respond, “yeah, right!”. It was absolutely unfathomable to me that someone wouldn’t be thinking about food all the time. Now I know that this was because my body needed more of it!

As I began my recovery journey, I found it hard to imagine a world where I wasn’t thinking about food all the time, but now I can confidently say that I’m there, and it frees up so much space to appreciate other things. Okay yes, to be fair, I still overthink other things instead, on occasion. But it is possible to have life on the other side, and it’s much more enjoyable.

Image Credit: Leadville Race Series ©

9. You can continue to exercise, it just makes it a little harder

I quit running to recover my health and my period. My body balanced back out within a few months. People often ask me if they need to stop working out to recover from RED-S. The answer is, “it depends”.

For many athletes, the idea of stopping exercise altogether isn’t possible, and that’s okay, but if you continue to run or to train for a race, it needs to be with recovery as the main focus, at least to begin with. That means consuming enough calories to balance out that additional energy expenditure. 

That might be as easy as having two extra granola bars in a day, but it’s likely to be a lot more. If consuming more calories is going to be difficult for you, it may be best to take a step back or away from your sport to get started. That way you can focus on fueling and add exercise back in when you’re ready to increase your calorie consumption. It’s not going to be easy, but you can do this.

RED-S resources

I created a RED-S educational hub on YouTube to answer all your RED-S questions and take a deep dive into whether you have it.

If you do suspect that you’ve been underfueling, check out this free RED-S Recovery resource I created for runners who are in recovery. I've gone through all of the questions that I had been asked over the years and sought out the advice of the best experts I know on this topic. 

Fueling more can be scary or it can simply be a case of needing to add a few additional calories in a day. Only you know which one of those feels true to you. Regardless of whether your underfueling is intentional or unintentional, there's a way out. Your body will feel better on the other side and your performance will improve, even if it feels as though you're going backwards at first. 

Stay patient and positive, and most importantly, trust in yourself. You know the right answer; you just have to listen.

Further reading