Blog

Disordered Eating in Ultra Endurance Cycling and Running

Written by Clare Pearson | Feb 10, 2026 10:24:10 AM

In an earlier blog on RED-S I wrote about how under eating can be intentional or unintentional i.e. there could be an underlying eating disorder or not.

In this blog, I am going to explain more about the prevalence of under eating in Ultra Endurance Cycling and Running and how to make sure that you adequately fuel your body for the demands of your sport.

For anyone who thinks they might have an eating disorder please seek professional help through your doctor and a qualified dietitian.

What is an Eating Disorder?

An eating disorder is a generalised term to describe a range of symptoms in relation to how much food someone eats, how frequently and what they do to themselves once they have eaten food.

It’s very simplistic to say there are two main types of eating disorder when in reality the expression of disordered eating is numerous and varied. However, in the interest of focus, broadly speaking there are two types of expressions:

  • Over-eating (which may or may not include purging).
  • Under-fuelling/low energy availability (which may or may not include purging)

For this blog we are talking particularly about under-fuelling and restrictive eating patterns, which can occur with or without a diagnosable eating disorder such as anorexia nervosa. Other types of eating disorders are very serious and just as distressing, but they appear less frequently in the Ultra Endurance setting.

Restrictive eating disorders can be chronic conditions which go on for decades with several interventions, recoveries and relapses. The sufferer will be in a state of under-fuelling/low energy availability for long periods of time (from months to decades), severely restricting food intake and/or engaging in an excessive amount of exercise to burn calories.

People with this type of disorder will find it incredibly difficult to eat normally, even when they know that they are causing themselves harm which, amongst other things, can include heart failure and death. It is often accompanied by a distorted body image, where someone, despite being severely underweight, will see themselves as fat, or focus on a small amount of fat in one part of the body, and see this as evidence they are over-eating.

It is a very distressing illness for both the sufferer and for their friends and family.

Anorexia nervosa can go by unnoticed in an endurance world because:

  • Exercising a lot - often multiple times a day - is normal and accepted
  • Long training sessions can mean training over a mealtime (and therefore the meal is skipped)
  • Low body fat is seen as normal and accepted (and often encouraged)
  • Loss of menses in women can still be seen simply as a sign of hard training rather than the serious health concern it actually is
  • It is very easy to be in a state of under-fuelling/low energy availability during high volume periods of training
  • Mostly, sudden and drastic weight loss can (initially) lead to a marked improvement in performance leading people to believe that maintaining unhealthily low body mass is an acceptable way to beat the competition. Achieving ‘race weight’ is widely practised and encouraged amongst pro teams for key races.

 

Signs You May Be Under-Fuelling Or Slipping Into Disordered Eating

Often it is the people around you that will notice there is something wrong before you do. It can be very difficult for them to discuss this with you and even more difficult for you to hear what they have to say. They may notice a drastic weight loss which you may feel initially proud of and note that instead of looking good you look drawn and tired, for example. They may notice your increasingly restrictive eating habits, which you see as positive steps to maintain or improve weight loss. Intimate partners may notice a change in your mood and libido, the growth of lanugo hair on your face and other parts of your body and even a change in your smell (your breath and sweat smell differently when your body is eating into muscle tissue for energy).

If friends and family are expressing concern about your weight and eating habits, however hard it may be for you it is important to remember they are saying these things because they love and care for you and are worried. This is important feedback for you that what you see and perceive is very different from what the people who love you see and perceive.

Things to look out for in yourself which may flag an eating disorder in addition to what other people notice include many of the symptoms of RED-S such as:

  • Negative mood change - more depressed, grumpy, less motivated
  • Negative energy change - feeling more tired than usual
  • Unusual thirst especially at night
  • Waking up hungry in the middle of the night/early hours of the morning
  • Feeling stressed about eating
  • An increase in performance followed weeks later by a drop which continues despite rest.
  • Inconsistent performance 
  • Increasing injuries including stress fractures, muscle pulls/tears and tendon problems
  • For women suppressed fertility is often seen in loss of periods or significant changes in menstrual flow including very light or very heavy bleeding
  • For men signs of suppressed fertility include loss of a usual morning erection
  • Muscle weakness and frequent muscle cramping
  • Compulsion to train even when that training does not contribute to your fitness and/or you are injured/ill
  • Feeling soothed when hungry/in under-fuelling/low energy availability/going without food

This list is not exhaustive and the reality is that eating disorders have very personal expressions which may be unique to you.

What is Healthy Eating?

Healthy eating is difficult to define because it is culturally based and individual. Often people who have suffered or who are suffering from an eating disorder can be seen to have recovered because they have gained enough weight. However, relapse can often occur at another point because the psychological and/or psychiatric factors contributing to the disorder have not been (fully) addressed. Just as the illness itself is complex and unique, so your pathway to recovery will be and what works for one person will not necessarily work for another.

From a physiological point of view eating enough nutrients including macronutrients and micronutrients is often the starting point in order to prevent further deterioration and in severe cases death.

However, healthy eating requires us to have a good relationship with food and a realistic and healthy relationship with our body. When we have these things we can listen to our body’s needs and respond to them appropriately. In short eating enough is not the long-term solution, your diet needs to be backed up by healthy psychology.

Psychologically various methods have been tried over the years including Cognitive Behavioural Therapy, prescription of anti-anxiety and/or anti-depressant medication and family therapy.

For those living in a family setting, family therapy has proved popular and successful in a significant number of cases and even more successful when combined with medication and/or additional 1-1 therapy.

The latest research around neural pathways associated with anorexia has informed successful interventions. When sufferers are educated about the neural processes involved in the eating disorder and supported to create new better habits around food and eating they recover well. This is especially the case when this type of intervention is combined with family therapy where appropriate.

What are the Specific Requirements of Ultra Endurance Athletes?

For endurance athletes there are particular elements to consider.

Firstly, while stopping exercise could be a life-saving intervention, when used as a ‘punishment’ this is unlikely to have the desired effect.

In addition, for those on high volume training the amount of calories needed is difficult to calculate. Initially, with the weight gain there may be some reduction/stagnation in performance as the weight increases more quickly than the fitness gains that can ultimately be expected. This can drive the sufferer back into a default mode of ‘it’s not working, I feel bad’ and needing to feel soothed by old behaviour patterns.

For athletes it’s important to create good eating habits which fuel the body both for the demands of your sport and to maintain health and live the rest of your life with energy and vigour. The way you meet these demands is individual to you.

Here are some starting guidelines for ultra endurance athletes:

  • Aim to eat anywhere from 200-400 calories per hour of endurance exercise on any workout exceeding 90 minutes. Larger athletes or very long/hard days may need even more than 400 calories per hour. A lot of training watches/bike computers can help with this by having an eating alarm.
  • You should start all workouts well-fuelled with carbohydrates so you have enough energy to complete the session.
  • You need to fuel your body so that it can adapt to the training stimulus and recover; this means that even on easy days you should be eating well to promote this.
  • There are no exact numbers when it comes to how much you need to eat (despite what many apps suggest) but a good starting point is:
    • Carbohydrates: 5-12 g/kg of body weight
    • Protein: 1.5-2 g/kg of body weight
    • Fat: 0.5-1.5 g/kg of body weight.
    • The margins are wide because individual bodies require different amounts and everyone may vary depending on the volume and intensity of their training.

Despite what you may be hardwired to think eating a little bit more than you need is far safer, healthier and overall better than eating a little bit less than you need. Chronically eating at the lower end of the scales outlined above can still be very unhealthy and damaging to your performance.

It’s often better for people with a history of anorexia not to calorie count or become too focused on numbers but to simply develop a good eating routine with a variety of different foods. Our spreadsheet may help by guiding on meals, snacks and amounts without being overly specific.

How you achieve all the above will vary and finding habits that work for you and your family if you live in a family will help you find routines that last.

Good rules of thumb include:

  • Ensuring you have at least one cooked meal each day with grains/potatoes, protein and vegetables and two smaller meals. For many people this is Breakfast, Lunch and an Evening Meal.
  • If you struggle with large meals/helpings having more frequent smaller meals that still include grains/potatoes, protein and vegetables can help and can fit better with some training schedules.
  • Having a high carbohydrate snack 1-2 hours before harder/longer workouts.
  • Having a mixture of carbohydrates and protein within about an hour after a harder/longer workout; this can be a recovery shake or ‘real food’ or one of your meals if that fits
  • In high volume periods of training and/or if you struggle to eat large meals having high quality nutrient dense snacks throughout the day (every 2-3 hours) which include both carbohydrates and protein
  • Investing in foods that contain enough calories for you to eat regularly during those longer workouts. These can be sports-specific snacks like gels and bars, ‘real food’ or a mixture.

Staying Healthy - Psychological and Physiological Risk Factors and Protective Factors

The individual nature of eating disorders means that there is really no one clear answer, but what can be helpful and what you may work through with a therapist are some personal risk factors and some protective factors.

Risk factors can include triggers to old habits and routines, risky feelings, thoughts and behaviours.

Protective factors can include:

  • Healthy routines,
  • Helpful people to have around you
  • Mantras or counter arguments you can say to yourself when you feel risky thoughts and feelings arising
  • Daily routines that help you feel good about yourself and in a positive frame of mind

An example of how this might look for someone is:

Trigger

Bad race result

Risky feelings

Frustration, anger, disappointment

Risky thoughts

I am too fat

I need to lose weight/be thinner so I can perform well again

Helpful, protective behaviour

Accept and allow yourself to feel the frustration, anger and disappointment

Have a cry if that helps or a rant if that helps.

Allow yourself a few minutes of this before moving on to something more constructive.

Talk through the results with a coach or knowledgeable friend, including your thoughts and feelings.

Share the risky thoughts around body weight and how you have linked these to the race result with a therapist or trusted knowledgeable friend

Protective, helpful thoughts

Everyone has bad race results from time to time this is all good information that I can use to improve for next time.

I am working hard to fuel my body so that it can perform at its best but that doesn’t mean I can expect perfect results every time. Did I eat enough? If I did then there is likely another reason why I didn’t perform, I can discuss this with a coach and/or look at the data and other factors.

It’s normal to feel frustrated, angry and disappointed after a disappointing result. I can allow myself to feel these things and process them in a healthy way

Establishing good habits and changing the neural pathways takes time and as with any new skill or habit it is not easy at first. Putting in some work to do this in a way that matches you, your culture and your nature will help. This might require sitting down with family to talk about mealtimes but also providing some strong rewards when you achieve a healthy eating habit - a bit like children who get stickers and after five stickers they get a treat but for you the reward needs to really resonate with you as much as the new habit.

An example might be creating the habit of sitting down to eat breakfast at 7am every morning and having a bowl of porridge made with (plant based) milk. Once you have had your porridge you could then sit down and enjoy your favourite coffee. Or it might be that while you are eating your porridge you allow yourself the guilty pleasure of watching silly YouTube videos that you don’t normally allow yourself to waste time on.

Being realistic about what to expect as you recover and working on your own risk areas will be a good way to create a long lasting recovery plan that works for you. You may need the help of professionals whom you respect and with whom you have a good rapport for it to work.

The following sections are more in depth covering the following:

  • What to expect as you recover
  • Why relapses happen

If you are an athlete in recovery or you are supporting someone in recovery you may find the following sections helpful.

If have all the information you need without reading any further, your understanding of this blog will not be compromised if you choose to skip the next few sections.

What to expect as you recover

Weight Gain

This may initially make your sport feel harder as you are carrying more weight and the muscle may not have developed at the same time. You can feel bloated and full in a way you are not used to.

Your body has adapted to high energy output with low energy input and it needs to adapt back; it will not do this overnight. After a period of starvation your metabolism is and other bodily functions are likely to remain in an energy-conserving mode for some time. For your body to fully adapt and start behaving and responding normally you will need to be energy positive - this is not about eating ‘just enough’ but eating more than enough until your body can adapt.

This can be a psychological and physical challenge if you are continuing to train. A good strategy might be to treat your recovery period as an ‘off season’ where you are on ‘light training’ this will help you recover from latent stress injuries and make it easier to be energy positive whilst not depriving yourself of the sport you love.

Change in Size

This is of course the same as weight gain but can be a real hurdle for people with an eating disorder who may feel they should fit into a certain size of clothes or become distressed when their clothes stop fitting and they have to buy a bigger size.

Part of adapting is adapting to a new body which has fat and muscle (ultimately) and this can take time. Wearing loose fitting clothes can help during this phase.

Comments/Watchfulness from Others

As you start to eat more and gain weight you will get comments from very well-meaning friends and family which may or may not be helpful for you. You may also feel a bit like you are in a goldfish bowl at every meal where people keenly watch what you eat - this is not imagined, this is exactly what’s happening as concerned family members want to see you eating well. They may ‘over-encourage’ at these times and this can be stressful. Being open with people about what is helpful and what is not helpful for you can help everyone adapt.

You may find others outside your close social network and family also make well-meaning but unhelpful comments which are ‘triggers’ for you. You may need to have a robust plan in place to deal with these as a risky situation.

Hunger

At some point the body crosses over from energy conservation to upping demand as it realises that food is now plentiful. This can lead to feelings of hunger that you may not have experienced for a long time and can cause stress as you are not sure how and when to respond.

Eating to hunger is ultimately the best outcome for athletes as it helps them adapt energy intake to their body’s demands, but if initially this is too scary, stick to the plans you have in place.

Ultimately eating disorders are a complex range of illnesses which require carefully planned recovery protocols designed and adapted to you as the individual. Factoring in ultra endurance training requires another layer which it is important to take into account. The end result should be someone who is performing well in their sport and living a full and active life.

Prevalence of Eating Disorders in Ultra Athletes - How the Psychology of Ultra Endurance Maps to Disordered Eating

There is a well-known link between over-exercising and anorexia nervosa as sufferers will seek to burn ingested calories. Endurance sport can become a more socially acceptable pathway into this behaviour; typically there is the popular belief that high volumes of training lead to better results. This is not strictly true as you can see in my blog here.

There is some argument that Ultra Endurance Athletes share some psychological traits with sufferers of anorexia, including perfectionist tendencies and a need for high achievement, characteristics which can lead to some good results in ultra endurance sports.

A proportion of people who have suffered trauma will turn to ultra endurance sport to help with their recovery. There is also a proportion of people who will develop an eating disorder after experiencing trauma, especially in early life. There can be an overlap between these two either because someone over-exercises to soothe or because they already had a pre-existing eating disorder and are trying to follow another, healthier pathway to recovery and experience relapses into disordered eating.

In addition to this there may be a genetic disposition to disordered eating in that people with parents with an eating disorder are more likely to develop one themselves. This also has a social element in that the food behaviour modelled by the caregiver is seen and copied by the child, who then develops similar eating habits that they carry into adulthood. This is not dissimilar to the genetic pre-disposition for sport where people who have one or two parents who are good at sport often end up being proficient themselves, again with the social component - if you’re mum and dad go to races, they will likely take you to races too and/or you will model their behaviour.

Interesting studies (summarised here: https://www.sciencedirect.com/science/article/pii/S2772408524001455#sec3) are now showing that in addition to all this there are particular neural pathways that develop in people suffering from anorexia where eating low-calorie foods becomes a default choice and being in calorie deficit has a strong reward link.

When seen at this neurological level we can see that it is not that someone suffering from anorexia is ‘choosing’ to eat less. The interplay of changed/different from the norm neural pathways create habits and feelings around associated with anorexia (e.g. anxiety, lack of hunger, feeling soothed/better when hungry/not eating).

Once started the reward based neural pathways (feeling good when starving) are habit forming and can, if not addressed appropriately, lead to a ‘default setting’ which either stays on some level or reappears under times of stress. This can be changed because as we know neural plasticity exists in everyone, but it requires a different approach from what we might use if someone were choosing to behave in a particular way.

We know that endurance sports carry similar habit based and reward based neural pathways - once you start training the positive mood from the hormones produced make you want to continue the behaviour. In fact, forming an activity habit is often a very good way to get and stay fit as John has written about here.

In addition to this, exercising at a low (zone 2) level can have a calming effect thus counteracting anxiety, a feeling often experienced by people with an eating disorder like anorexia. The motive to exercise can then become confused as at times it is a healthy alternative to restricted eating, at others it becomes a way in which to burn calories. This is not necessarily consistent in one person and may change depending on your emotional well-being.

Conclusion

Humans are complex and each of us is completely unique. The reality is that there is no one pathway into an eating disorder and it is likely that clusters of risk factors come together which then create coping mechanisms for which we may already have a social and genetic disposition.

For ultra endurance athletes there are particular risk factors that can lead to disordered eating and particular nutritional guidelines which fall ‘outside the norm’ that we all need to take into account to stay healthy and perform at our best.

Ultra endurance cycling and running can be a fun, healthy pastime and, for some, an amazing sporting career. Whether you are recovering from an eating disorder or worried you might be slipping (back) into disordered eating, with the right help and commitment you can recover and enjoy the sport you love.

You can learn more about our personality-based coaching tools in other  blog articles and on our YouTube channel.