As well as being a world record-breaking endurance runner, Fiona Oakes is also known for her advocacy of a vegan diet and tireless work to champion animal rights. With a gruelling training regime currently averaging around 100 miles a week, she manages to stay well-fuelled and energised on a purely vegan diet, which she's followed from a young age.


She has competed internationally in more than 100 marathons, completed the Marathon des Sables 3 times and set five marathon course records around the globe - including The Antarctic Ice Marathon, as well as being the fastest woman to run a marathon on every continent plus the North Pole consecutively. Astonishingly, this is all despite having to undergo 17 radical knee surgeries and having her entire right kneecap removed.

A large motivating force behind her elite running performance, Fiona is also an ambassador for animal rights and is keen to promote the virtues of an ethical vegan lifestyle. She founded the Tower Hill Stables animal sanctuary in 1996, where she cares for over 600 animals and is also the co-founder of the hugely popular Vegan Runners club in 2004.

We were keen to know how effective a vegan diet is for building strength and endurance over such long distances. Here, Fiona discusses her training diet, motivations and life philosophy, along with some inspiring tips for aspiring vegan athletes and ultra runners.

For more diet and fitness tips, read our interview with vegan duathlete, Lisa Gawthorne and check out our series of Eat like an athlete guides.

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When did you decide to go vegan and why?

I went vegan when I was six years old, purely and simply because I loved animals and was both concerned and upset about the harm inflicted upon them in the meat, dairy and other related industries. At the time, I don't think I had heard of the word 'vegan' and certainly none of my family or peer group were either plant-based or vegetarian. So, more than being a decision, it was a reaction – I gravitated towards the concept and ideals of veganism as a place I felt comfortable inhabiting.

What does your typical daily diet look like when training for a big event?

Until recently, I always thought my diet was pretty unusual in that I only eat one meal a day in the evening. In fact, it wasn't until I was at a huge marathon event in Russia that I was attending as part of my world record attempt that I became aware other athletes actually follow this regime, too. The IAAF had put on a lunch for elite competitors and, in passing conversation, I explained to one of the Kenyan running coaches that I wouldn't be attending as I didn't eat lunch. Fully expecting him to be shocked, he just said 'Ah, the warrior diet.' It's also called intermittent fasting, and it apparently works on the principle of the body being at its optimal energetic, physical, mental and passionate peak when in a regime of 'under-eating' during the day and 'overeating' at night. I say 'apparently' as I just happened upon this way of managing my diet as it best fits around my hectic days running the sanctuary and I find myself more energised for my training.

Read more about intermittent fasting diets and discover the health benefits of fasting.

Do you find that a plant-based diet boosts your performance?

Since I have always been plant-based, I can only refer to my actual lifetime experience with this way of fuelling myself rather than from a 'before and after' perspective. Having said that, I will say that I have being running at an elite level for almost two decades; I have massive versatility in my running resume, ranging from 10km to ultra-stage racing successes; and believe my constant ability to recover at an accelerated rate and put in the intense and extended endurance sessions is wholly down to my long-term plant-based diet. I am always very proud to attest that I have never actually incurred a running injury. Obviously, I have injured myself in my day-to-day life, which has, at times, impacted my running – most famously perhaps fracturing two toes three days before flying off to attempt the Marathon des Sables for the first time – but nothing actually caused by the constant pounding of the body running up to 100 miles a week inflicts.

Fiona Oakes racing in the desert

Are there any nutrients that a vegan diet may lack for ultra-endurance athletes, and if so, how do you make them up?

I always say to anyone that the best way to make up your diet suitably for day-to-day life is with balance and finding out what suits you and your individual requirements – this is always a very beneficial exercise. However, if you are a person who leads a very vigorous life, you might find your body needs a little extra to keep it running at its optimum level. Potassium, magnesium, zinc and sodium are some examples, but can all be gleaned very successfully from sources such as sweet potato, brazil nuts, lentils and, as in the case of salt, just adding a little more to your food.

What are your main sources of vegan protein for muscle recovery and maintenance?

Personally, I don't actually take any supplements or commercially produced and synthesised products, and prefer to rely on natural sources such as pulses, which are an edible seed that grows in a pod. This includes all beans, peas and lentils, and I find they make a great, low-fat and affordable source of plant protein and provide plenty of variety, too. People are often surprised to find that not only can a vegan diet reduce inflammation hindering recovery time, but it can also combat oxidative stress induced by exercise.

Read more about the health benefits of a vegan diet and the best vegan protein sources.

How do you stay hydrated when training over such a long distance?

Hydration is always a key to optimum performance, not just in sport but in everyday life, but I have personally found it probably the single most important element of running in the extreme climates, terrains and distances the ultra-stage races demand. It's a tricky one, as water is limited by the races, so you have to learn to manage your intake very carefully and sensibly. A very robust electrolyte programme is imperative and should be tried, tested and tailored to your individual needs well before any event. I always find salt tablets very helpful too, as they help you retain more fluids during high-intensity exertion and physical work. It's a bit of a science to start, but you soon get the hang of it through experimentation and experience.

What are your favourite vegan snacks for boosting energy?

That's an easy one, I love dates, marzipan and salted cashew nuts.

Give yourself a boost with these tasty date & walnut cinnamon bites, and check out more vegan snacks.

Dates filled with walnuts in a circle on a plate

Is it true that ultra runners get to eat cake during races?

Yes, that is completely true – depending on which race you are doing! Some races supply lavish 'banquets' for runners at checkpoints, and I have seen all manner of luxuries and goodies on offer to tempt runners and keep them going. I have to confess the races I prefer are the ultra-stage extreme races, which are held over a week and require total self-sufficiency. The races only actually supply a limited water ration but, believe me, in the middle of a desert at temperatures often exceeding 50 degrees, a bottle of warm water tastes like nectar!

Which of your many racing achievements are you most proud of?

I don't know whether you can call it a 'racing achievement', but it is a direct result of my running so I hope it counts – it has to be co-founding Vegan Runners in 2004, affiliating it as a recognised UKA running club. At the outset, it had only a tiny number of members – watching it grow in the years since to one of the biggest running clubs in the UK and a support resource for so many new runners, vegans and all those interested in a vegan lifestyle has been amazing. It's become a real global community of people proudly showcasing the idea of running for a reason, and the green-and-black vest is now spotted on just about every start line you see anywhere you might be. I have always been proud to put on this vest and place in the top 20 of London, Berlin and the Great North Run. Wearing it has been very special to me, as the promotion of veganism is the reason I am actually out there running in the first place, demonstrating to the world that veganism is not prohibitive to any form of extreme endurance challenge.

What would your all-time favourite meal be inside or outside training?

I am always pretty much training for something, and have kept up my activity level through the pandemic even though races have been on hold, so my diet always remains pretty constant. I think my favourite vegan meal is just about anything my mum – who does all the cooking – decides to prepare. She makes everything from scratch and her soups are something to really drool over. So, I would have to say, homemade soup and bread – pearl barley hotpot followed by date cake, if I have any appetite left!

Make our nutritious and warming Danish-style yellow split pea soup with rye bread for a wholesome recovery meal.

Bowl of yellow split pea soup

What do you typically eat after a big race?

After a marathon or shorter ultra – say up to 100km – it's always just plenty of carbs, rice, pasta and pulses. After an ultra-stage race, even though you can find you shed enormous amounts of body weight, I find I have to build back up to eating normally gradually, as, for some reason, my body seems to adapt to having less very comfortably, so it will be a similar pattern but just smaller portions.

Have you come across any misconceptions or myths surrounding the diet of an vegan ultra-endurance athlete?

Yes, many, and especially relating to that of a vegan ultra-endurance runner, as many people think it just would not be possible to retain the level of physical strength and fitness required for such extreme and arduous events by basically eating plants. For me personally, people tend to think there will be some 'magic' ingredients, secrets, huge quantities or expensive supplements to fuel these events, but in my case there really isn't. I actually think the most critical key is to have a very balanced intake of food during your training and just adapt it before and after races. I find the basic foods are the best for me, and I like to keep my race food and snacks pretty much as is practically possible to that of my daily diet.

What would be your top diet and exercise tips for people considering starting on ultras – especially those who are following vegan diets?

Balance is key, and learn to know yourself and your own body. Mental strategy is imperative too, as these are very tough and demanding events that make you really question your ability and motivation, so always remaining focused on why you are out there competing.

Always remember that you are a unique being and your dietary requirements will be similarly unique, too. Listen to the messages your body is sending you, learn to interpret them and act accordingly. If you feel tired, weak or fatigued, or can't sustain longer runs or periods of training, look at what might be lacking in your diet or is maybe too abundant. Don't be afraid to experiment with eating plans as you would with your training plans, and seek information from all sources to find what best suits you as an individual.

Remember that rest and recovery is as important a part of your training as the actual running. For sure, you will make mistakes, but so long as you learn from them, they are beneficial to your progression in your chosen event. Not all runs and races are easy and many don't go to plan, but you tend to derive more information and depth of self-knowledge and awareness from the ones that are most difficult and take you to the darkest places – the important thing is learning how to get through them and to the other side.

Running, and especially the ultra runs, has been a life-changing and enhancing experience for me, full of many diverse challenges, but these have truly repaid and rewarded me with an exponential abundance of mental and physical strength, fortitude and fulfilment many times over and continue to do so, year in, year out.

For more tips, check out our 7-day vegan marathon meal plan.

Vegan falafel burgers

What next big event is coming up for you in future?

Regarding races, I have been selected to represent England in both the 10km and half-marathon at the beginning of September – something I am really proud and excited to do. Beyond that, I have run the qualifying time for an elite championship place in the London Marathon in October. I am also entered into the Marathon des Sables, tipped and hoping to do very well this year, as it is the event I have been really training hard for, running up to 100 miles a week on and off road as well as trying to work on other core strengths and skills such as climbing, dune running and the specific limited nutrition and minimalistic survival ability the event requires.

Marathon des Sables and London are held at the same time, so there will have to be a decision made nearer the time based on the logistics and regulations surrounding covid and travel. It's all a bit of an uncertain waiting game, and quite hard to work out a training programme with the speed, endurance, strength and versatility such a diverse spectrum of distances and possibilities require. However, the main thing to remember through all of this when feeling down, lacking motivation or searching for inspiration is that we are blessed to be able to get out there and train at all. It's a perfect illustration of the message I am trying to convey: health truly is wealth. So, at the moment, my mantra has been to prepare for everything, expect nothing and be truly grateful for anything.

Do you have a favourite recipe from

My mum assures me the vegan banana bread recipe is the best she has ever come across, and I would endorse that by saying it is the finest I have ever consumed.

Use up your ripe bananas in our popular vegan banana bread recipe – ideal for breakfast or an afternoon snack.

Vegan banana bread slices on two plates

Discover more vegan fitness and health guides...

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Find out more about vegan ultra-runner Fiona Oakes and her work on the Fiona Oakes Foundation website. Also check out the film documentary on her incredible running journey – Running for Good, available on Amazon Prime Video.

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