We get asked a lot about what we eat, and how we fuel during our endurance events. It’s a mystery still to many endurance athletes as to why their go to works, and in all honesty the secret is personal preference.  Despite all of this, we thought it was about time we put down what works for us, in the hope we can offer some solution to the struggle many of us feel. We’re not saying what works for us will work for you, but hopefully within our many epic fails there will be a win for you! 

During anything under 10km we tend to refrain from eating anything, unless it’s very hot or humid, we’ll miss out on carrying a water bladder or bottle. Saying this, if you are training for something a little longer that does require you to carry water these distances are great for practice runs with the bag. Once we hit the half marathon marker we start to take on board fluids and think about packing a small snack or two. Anything over a marathon, water and food is a must! So, there’s the basics when it comes to the yays or nays.

First, we are going to run though how the body burns and utilises energy during an endurance event. Endurance running is an aerobic activity. This means that you are using the oxygen you are breathing in to help in the process of creating energy to keep you moving. Anaerobic exercise (sprinting/weight lifting), is when oxygen is not used in the production of energy, but this can only power you for a limited amount of time. The anaerobic system in the body produces energy (ATP – Adenosine triphosphate) rapidly, but only on a small scale, hence it can only be used for a limited period. The aerobic system in theory can run continuously if we keep breathing (supplying oxygen) and keep taking on board carbohydrate (glucose). 

Most of the population will utilise the aerobic system when running and so use carbohydrate as fuel. There are a small percentage of people who choose to be ketogenic, which means they consume little to no carbohydrates and therefore use fat as a primary energy source.  If you have fuelled correctly for an endurance event when you set off your body will utilise the glucose present in your bloodstream first. Once this is used up your body will break down the glycogen stored in the muscles and liver into glucose, and send it to the bloodstream to be used in the same manner. Once you reach this stage you must begin taking on board carbohydrates to keep the aerobic energy system going otherwise it’s likely you will ‘Hit the Wall’. 

Fat is also used in the aerobic energy system. The body utilises fatty acids from either the digestive, lymph, or circulatory systems or fat stores (adipose tissue) to aid the production of ATP (in glycolysis).

Protein is more essential post workout to help with growth and repair. However, for marathon distance and over we do try and take on board a little protein. The metabolism of protein does play a role in the production of ATP (via the Krebs cycle)

When it comes to what we munch when we crunch miles, it’s all about those carbs! Next on the list are electrolytes followed by fats and finally protein. 

Our few of our favourite ‘in race’ snacks:

Lucozade Jelly Beans 

Energy gels are not our thing, they taste yuck and the consistency is well ‘blergh’… for a better use of words! When it comes to these we think the jury is out! Yes, they are designed to provide us with exactly what we need, but for us they are way too sweet, sticky and sickly. If, like us you too find them hard to ingest and digest then we suggest you give these beans a whirl. We to tuck into these around half way through said distance, or when we begin to feel tired. We’ll then spread the snacking out enjoying a few throughout 20 minutes periods to keep our blood glucose levels topped up, preventing a spike followed by a crash. Each 30g pack contains 27.6 grams of carbohydrates! They are basically just sugar and glucose syrup. Normally we would tell you to eat these in moderation, but when you are putting your body to the test we’ll let you off. Due to them already being in simple sugar structures they can enter the bloodstream quickly and keep the aerobic energy system ticking over. We call them our magic beans and we wouldn’t enter a challenge without them!


TTH Fruit ‘n’ Oat Bars

These were created in the TTH kitchen during our short but sweet training time ahead of the 2015 London Marathon. We had just begun increasing our weekend mileage and we couldn’t seem find anything that would sit well in the stomach whilst running. This bar is bursting with dried fruit and honey (more than we would put in a normal snack bar) to give us that quick hit of glucose. The oats are a complex carbohydrate and so take a little longer to be broken down into glucose, therefore slowly bring up the blood glucose levels a while after eating. Coconut oil is an excellent source of healthy fats which can be used in ATP production, and therefore is also an excellent tool in keeping us energised and fuelled.


If you are prone to sweating like E then replenishing your electrolytes and fluid levels are absolutely essential. Even if you are less heavy on the fluid loss like H, you will still be losing more than you think via your breath, evaporation and urine so it’s just as important to stay hydrated. We love nuun’s range of flavours and they have no scary ingredients. Each tablet is packed with vitamin C, calcium, magnesium, sodium, and potassium. The change of flavour has the psychosocial benefit of making us take on more water, alongside topping up our electrolyte stores which helps prevent cramp, aid muscle function, keep the gut functioning properly, and boost energy levels.

Bounce Balls 

These little bundles of joy are so easy to chuck in your backpack or little zip pocket. They are a great triple whammy of carbs, fat and protein, as well as being nutrient dense meaning we can get in 150-220kcal per ball. They are perfect for munching on the run (quite literally), and contain no hidden nasties meaning they sit well despite all the jiggling round when jogging.

Nut Butter 

Nut butter has been getting bad rep in recent ‘health’ news due to its high calorie content. It also gets bad rep in the endurance world for being high fat, linked to fears of ummm speeding up the digestive system. We, however find there is nothing better than a little squeeze of nut butter when striding out on long runs. We love mindful bites ‘straw’ sachets. They are super easy to open on the move and the straw makes things a little more sanitary when we are sharing one between us, packing in a perfect power punch of proteins and fats.

 TTH 5 Top Tips when considering your in race nutrition:

  1. Practice – Like most things practice makes perfect, so be sure to test out your racing fuel on your training days.
  2. Weight – Remember you need to carry food and water for longer races so be sure to plan ahead so you know what you will need, and don’t run the risk of over doing it. Having said that don’t be stingy on the water, especially if you are heading out into the wild.
  3. Practicality – Now you may love spaghetti carbonara as an ‘in race fuel’ but that is not going to be easy to eat on the move or keep well when brought up to body temperature in your pocket. You need food items that hold their shape, are easy to open and stay edible at various temperatures.
  4. Macros – Prioritise carbohydrates, then begjn thinking about small amounts of fats and protein
  5. Micros – Get in your salts (magnesium, sodium, and potassium) as this will help to avoid early onset of fatigue and cramp.


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