High Performance Ben Turner Nutrition performance and fitness consultation

Nutrition for Runners: 1/8

endurance nutrition running Feb 05, 2021

I have collated my top 8 nutrition recommendations for runners during training, in the race, the recovery and how this fit in with a healthy and balanced lifestyle.

It is important to note here that these are evidence-based recommendations and are backed by the latest scientific research, this allows for a reliable base in which to set the foundations of our nutritional knowledge. There is no doubt that these recommendations will differ between individuals, and preference and belief is something to be accounted for. Ultimately, as with any nutritional coaching intervention, the individual comes first, and advice should be tailored in a 1:1 setting. However, these recommendations allow for a reliable base understanding and will help you get the most out of your training.

Number 1: Pre-run nutrition

The fuel you need for your training run comes from two places, what you eat in the few hours prior to putting your shoes on, and your habitual diet. Starting with your everyday habitual diet, the breakdown of protein, carbohydrates, and fats (macro-nutrients) will help understand what will be burned as fuel for your run. If you habitually eat a higher carbohydrate diet, then your body will be more accustomed to burning carbohydrate as fuel. Carbohydrate is the body’s preferred fuel source, but it is not the only fuel source. If your diet is particularly high in fat, your body will be more accustomed to burning fat as fuel.

There are certain factors to bear in mind here, the first is that carbohydrates are the ONLY macro-nutrients that will increase its own oxidation. This means that when you eat carbohydrates, your body will prioritise burning carbohydrates until that fuel source is reduced. Secondly, the body can burn fat as fuel ONLY at lower intensities. The process of breaking down fat into energy is longer than that of carbohydrate and therefore the body struggles to do this at higher intensities.

In terms of performance, you are going to benefit from a pre-run meal of more simple carbohydrates.  If you see you body as a car engine that can burn both petrol and diesel, petrol represents carbohydrate and diesel represents fat.  Petrol cars are always quicker off the line than a diesel car, and the human body needs that carbohydrate to be able to get started with optimal performance.  Once the car gets to cruising speed, cruise control is switched on and you sit back and relax, in the human body, once you have reached you easy aerobic cruise pace, you are likely burning more fat (diesel) as fuel. 

Carbohydrates will get you off the line and fuel your higher intensity sessions, so remember to eat some before your training run.  Simple carbohydrates are low in fibre which reduces the risk of digestive discomfort during training.

Those who have a higher body-weight, and more body fat are likely to benefit from reduced carbohydrates and increased fat. This is due to both the preferences the body places on the processing of foods when overweight and the palatability of carbohydrates leading to over-consumption, a calorie surplus and further weight gain.

The fat adaptation theory comes into play here, but this will be covered in a separate blog of its own.

Key Points:

a. If you eat a higher carbohydrate habitual diet, your body will be more accustomed to burning carbohydrates as fuel. If eating a particularly high fat diet, your body is more accustomed to burning fat as fuel.

b. If in a calorie deficit for weight loss or eating a healthy balanced diet with moderate intakes of both carbohydrates and fats, it is likely you will benefit for carbohydrates as your pre-run meal.

c. Consume carbohydrate prior to your training sessions.

d. If you are overweight, it is likely that a smaller, higher fat meal will benefit both to aid in a calorie deficit and encourage further utilisation of fat as fuel.

With habitual diets examined, now we need to look to the intricacies of what to eat prior to our run. The first question that should be asked is, what is the training session? The intensity, duration and stress of the workout will dictate different requirements. This will also impact how long to wait between eating and exercising to ensure you do not encounter gastro-intestinal discomfort.

The longer the session, the more calories you are going to burn, and therefore the more calories you may require prior to starting, this comes from pre-loading carbohydrates, your habitual diet and fuelling during your run, which will come in a future blog.

Research suggests that consuming 1–4g per kg or bodyweight of carbohydrate, 1–4hrs prior to exercise is an ideal range to consider on race day. However, this is a large range and comes with certain interpretation. In my experience and recommendation, 1g of carbohydrate per kg of bodyweight will suffice for your high intensity training sessions and long sessions that are over 1.5hrs.

Your pre-run meal should be low fibre as fibre is an indigestible carbohydrate that stresses the gut machinery (in a good way). This is great in the everyday diet and more fibre should be consumed, but this is not the ideal situation prior to a run. The last thing we want is to force our digestive system to work and demand blood for digestion while we are swirling everything around on a run. This is where vomiting, cramps, bloating and flatulence can come from.

Pre-run foods are often over complicated, and its easy to see how when you look into the science behind the specifics. However, it need not be, it is very much down to personal preference and something to be adapted to the individual. White bread, cereal, oats, and banana are all easily digestible carbohydrate sources that are low in fibre and provide adequate energy for most training sessions. Adding some protein to your pre-run nutrition strategy is also beneficial for those longer training sessions of 1.5-2hrs and beyond where your muscles are likely to experience damage and stress through prolonged activity.

Fat prior to exercise is less beneficial than carbohydrates but plays an important role in the body’s ability to burn both carbohydrate and fat as fuel, this is called metabolic flexibility. It should be noted that fat has 9kcals per gram, more than double that of carbohydrate and protein. As such these portions should be smaller to avoid bloating and discomfort during your run.  Remember, petrol cars are quickest off the line and there are limited benefits to solely consuming fat prior to exercise.

My recommendations include:


For shorter and easier intensity runs, for example and 5km recovery run. You can use this time to increase your metabolic flexibility, just make sure the intensity and duration are both low.

1x banana, 1x peach, 1x slice of melon or a cereal bar. ~60 mins before exercise

For training sessions of a longer duration, that require at least some fuelling, such as a 30-minute race pace, strength and conditioning, or longer easy pace run up to 1hr.

2x Slices of toast and jam, 2x poached eggs on toast or 50g of oats with raisins and soy milk* (~1g carbohydrate per kg bodyweight). ~90–120 minutes before exercise 

For sessions that require a bit more effort, for example and 30–45-minute lactate threshold, long run up to 70–80 minutes or race pace intervals. If your training session is 1–1.5hr, it is beneficial to eat slightly more pre-run. Equally, adding protein here is likely to improve your recovery. A note on toast: white toast is the optimal source of low fibre carbohydrate, but there can be a negative attitude to this and therefore, any toast will suffice as long as you are used to eating it.

*Dairy products can present GI-distress in some people and therefore it is not recommended before a training session. Dairy alternatives work as a suitable replacement should the preference dictate.

More food? >120 minutes

The more you eat the longer it will take to digest and the longer you will have to wait prior to exercising. Many people feel they need to eat lots prior to training, and it is not always the case. Your habitual diet will define whether you are adequately fuelled. If you have a particularly long training session or something that is very intense fore prolonged period of time. You are going to benefit more from eating more the night before as this will ensure you stores of glycogen (stored carbohydrate in the muscles) is higher and therefore primed for exercise.

Bottom line:

a. Don’t over think your pre-run nutrition. When training, this is our time to experiment with different foods and different quantities at different times, to find what works. What we are trying to avoid is trying something completely new the night before race day.

b. Remember the physical demand of your training session and adjust your fuelling strategy accordingly.

c. Try to eat some carbohydrates prior to your run, leaving at least 1hr prior to setting off depending on the size on the meal.  1g ~kg bodyweight is adequate carbohydrate intake.

d. Avoid fibre pre-run to prevent GI distress or the need to go to the toilet…

e. You need less than you think for those longer sessions.

Coming up in Part 2, how to fuel during your training and on race day.