How To Fuel for The Dragon’s Back Race (part 1)

Experienced sports nutritionist Renee McGregor shares her expert fuelling advice to help you go further. faster. on the world’s toughest mountain race. 

Some of you will know me from my work as a Sports Dietitian, others from my books and a few, hopefully, from my running. My work has stemmed across a couple of decades and I’ve had the opportunity to not only work within the clinical field of nutrition, but also in the world of high-performance sport. I’ve used these experiences to be among a very small group of practitioners who are bridging the gap between the clinical and sports world to provide evidence-based and practical solutions.

My work and ensuring that individuals get the right support and approach for them is incredibly important to me. But when I’m off duty, I can be found running in the mountains and chasing trails, most likely training for a crazy ultra-marathon. Last year (2022) I became British Trail Running Champion in her age group over the short course and 3rd female at The Spine Sprint. Recently I returned from the Mustang Trail Race, Himalayas, Nepal which covers 200km in 8 days and goes over 7 passes over 4000m, where I was 4th female and next year, I have my eyes set on the Dragon's Back.

Overview of the Dragon’s Back Race

The Dragon’s Back Race is a 6-day stage race covering 360km through Wales, starting at Conwy Castle and finishing at Cardiff Castle. The race provides overnight accommodation in tents, hearty breakfasts, post-race snacks and evening meals as well as transportation of overnight bags to each new camp daily and your dry bag of supplies to checkpoints during each day. 

However, it seems what makes this race is not just the hospitality and challenge of the terrain, but the people involved, that is the event team, the volunteers, and the other runners. There is nothing like the camaraderie of a shared challenge. For those eager to find out more, take a look at Montane’s story behind the race

Fuelling for Multi-Stage Adventures

Nutrition is not complex, but it is a topic of great controversy. When it comes to nutrition specifically for performance, it feels like everyone has an opinion but often this information is based on n=1, or the science, when it is available, is over simplified to fuelling and recovery.

In reality, human bodies are not machines; while we definitely need fuel to survive, it is not as simple as we can cover a certain number of miles when we fill our tank with a specific number of litres of petrol, as in the cases of cars.

In fact, when you stop and consider human biology, the body is an amazing piece of engineering that has the ability to manage a series of intricate processes that all interact and work in conjunction with each other to keep us alive. This is why fuelling is never as simple as just energy in versus energy out; it is about the composition of your diet, the timing of your nutrients and quantities it takes not just to meet the demands of your training load, but also how to continue to drive biological processes alongside.

Thus, when embarking on a significant challenge such as running the Dragon’s Back, ensuring that you make appropriate choices around your training and lifestyle will help you to maintain your training effort day after day, resulting in adaptation, progression and feeling more prepared ahead of the race. Studies have also shown that timing of nutrition has an integral role to play in hormonal balance, bone health and maintaining your immune system.

Fuelling for a multi-stage race

Carbohydrates are King

Carbohydrate is the key fuel source for exercise as it is broken down into glucose, the body’s preferred currency, and utilized by the body to provide energy. Carbohydrate is stored as glycogen throughout the body, but specifically within the liver and muscles.

It is this source within the muscle that is the most readily available energy for working muscles, releasing energy more quickly than other sources. However, this storage facility is limited. If the muscles are inadequately fuelled, it will lead to fatigue, poor performance and potentially putting you at greater risk of injury.

To give you some context, it takes around 500g of carbohydrate to have completely full muscle glycogen stores, with an additional 80g in liver glycogen, mainly used to maintain energy to the brain. Many of us take the brain for granted and don’t appreciate that it also needs a supply of energy. In fact, our brain needs around 120-130g of glucose a day to work optimally. Why does this matter when we are running? Because we need to be able to think and make appropriate decisions. 

When muscle glycogen is at full capacity, at most, this will last you around 90-120 minutes running at around 65-75% of your maximal heart rate. The quicker you go, the faster your stores will deplete. Thus, for those of you training most days, your glycogen stores are always slightly depleted. This is also an important consideration for this particular challenge. In addition, the mountainous terrain involved in the Dragon’s back means that even if you are not moving that fast, the effort to cover the ground will still be high and depleting your tank, probably a lot quicker than you think.

This helps to explain how important planning your carbohydrate intake around and during training sessions is; the amount you require will be dependent on the frequency, duration, and intensity of your training. However, regardless of what you may have read, exercise and running use a lot of energy. 

To help you meet your needs, it is important to understand the difference in the available types of carbohydrate. Over the years, carbohydrates have been classified in many ways; the most common types are simple and complex. 

Complex carbohydrates are those including pasta, rice oats, couscous, potatoes, bread and cereals. Simple include dairy, fruit and sugar, honey, molasses, etc… Runners need a mix of both. Ideally, complex carbohydrates at mealtimes and then more simple options immediately before, during and after, depending on the training session. 

How to fuel efficiently for a multi-stage race

Fuelling Early for a Big Race

When training for the Dragon’s back, while the majority of your weekly mileage is likely to be at an easy to steady pace, many of you will also include some higher intensity sessions such as hill repeats, tempo or intervals to help with overall running economy and speed.

When preparing for any of these runs, it is important to ensure sufficient fuelling in the 24-36 hours prior to ensure that you have full glycogen stores. This means consuming carbohydrates at all your meals and snacks during this period of time ahead of training.

When we are specifically looking at higher intensity runs, as mentioned earlier, when we are working at these very high work rates, our body can deplete our stores within 45 mins. Aim to take on easily digestible energy around 20-30 minutes into the session. Gels, chews, and sports drinks are great options.

When it comes to longer endurance runs, it is equally important to start fuelling early. However, due to the terrain and type of race the Dragon’s Back is, real food is a definite fuelling option. A lot of the athletes I work with who run these longer distances often find that they need to split their fuelling up, where they may focus on solid fuel for the first part of the run, then maybe move more towards gels and jellies, finishing up with liquid and caffeine. However, I cannot stress enough, it is finding the practice and options that work for you. I know some elites who can stomach gels even in 16 hours plus races, while others can tuck into boiled salted potatoes throughout 100 miles.

Some good ideas for real fuel include:

Cold salted potatoes

Noodle soup

Scotch pancakes

Peanut M and Ms


Wraps with filling of choice but good options include marmite, peanut butter and banana, cream cheese

Cereal bars

Salted peanuts

Top Tip

A key fact is the body can absorb around 60g of glucose per hour and 30g of fructose. There are some new studies emerging that suggest that this upper limit of 90g in total could be increased to 120g in some athletes who train their gut but presently the sample sizes used have been small and only done in men running at altitude. 

Similarly, a study in 2019 which looked at runners who participated in the Race Across America but also Tour De France cyclists does suggest that there may be an upper overall limit of how much energy we can consume over these long races. More information is needed but it is something to be mindful of as a strategy that works for you may not work for others. Personally, I have found in multi day events where I’m running 50K plus a day, my body prefers real food over sports products.

Fuelling on the go at a big race

Fuel On the Go

One of the most common issues reported with taking fuel when running is gastric distress. This outcome causes many runners to avoid fuelling during long or intense training. However, we have already heard the evidence for the importance of carbohydrate availability. The real issue is that many individuals do not practise fuelling during training but then go ahead and fuel during a race to ensure optimal performance. 

When I ask runners why this is the case, it is usually related to the fact that they want to “save” their energy for after training, so they have something to look forward to. This is definitely one myth that needs to be rectified. In fact, for optimal performance and recovery, fuelling before, during (on long runs) and after is best practice and actually helps with satiety and appetite.

Everyone will have their own personal preference when it comes to sports nutrition. It will also depend on the type of event they are preparing for: supported, unsupported; at altitude or in the desert; hot or cold; road or trails; single day or multi day and how long each day will be.

Whatever you choose, the key is practice, practice, practice until you have nailed what works for you. 

Some common mistakes that people make include:

Leaving it too long before they start fuelling; ideally you want to start taking on nutrition within the first 30 minutes and continue every 30-40 minutes.

Taking sports gels too quickly; aim to take one gel over 4-5 minutes rather than all in one go. This helps with absorption and also tolerance.

Becoming dehydrated and not taking on replacing fluids and electrolytes, specifically sodium.

Trying new products on race day

Looking for more expert nutrition advice?

Take a look at part 2 of Renee’s ‘How to fuel for the Dragon’s Back Race’ which covers electrolytes, hydration and recovery. For those eager to find out more about the Dragon’s Back Race, take a look at our event hub to find out more.