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Fuelling your run: You Can’t Out Run a Bad Diet – 6

This is the last in this series of posts on nutrition. If there’s anything nutrition wise that you have questions on, please contact me and I’ll do my best to help. This last post is all about fuelling your actual training sessions. This is really important both from a health and a performance standpoint. If you are continually undernourished when you go for a run, you will very easily become susceptible to illnesses and injuries, and your performance will suffer as a result.

General considerations:

Do I have enough energy to complete my training sessions?

Is my eating affecting my comfort when I’m training?

Am I eating the right things to support my immune system? – this last one is particularly important as you embark on the longer distance events, where the volume of training is likely to put a large amount of stress on your system.

As you prepare for your next race, your diet should follow normal healthy eating guidelines, however, you may want to ensure you have a little extra ‘fuel’ in the tank ahead of your long runs, and particularly challenging training sessions. In addition, add plenty of fresh fruit and veg to your diets, as well as foods that contain healthy fats, to help your immune system, such as nuts, oily fish, avocados etc.

Nutrition During Training

These guidelines come from the American College of Sports Medicine:

For training sessions less than 1 hour:
No need to take anything extra, other than water. You may wish to time the session so it’s a couple of hours after a meal so there is some fuel in the tank, but no need to over-eat.

For training sessions 60-90 minutes:
This is really down to personal preference. If the session is relatively low intensity, you will probably be fine with just water. If it’s high intensity, you may wish to consumed a carbohydrate drink. Equally, if its a low intensity session, but you feel depleted, there is no harm in having a carbohydrate drink to get you through the session. See blog on hydration for explanation of isotonic drinks.

For training sessions 90 minutes plus:
There is definitely benefit in taking on fuel during sessions of this duration. There are a variety of products on the market that are appropriate to this. Again, you need to consider a few things:
Can I actually carry the products?
Do they taste good?
Do they give any adverse affects on my run that I don’t want during my training run or race?

Basically, test things out. Sports medicine guidelines state that for endurance exercise, you should take on 1g of carbohydrate per kg of bodyweight per hour of exercise. This is about 2-4 energy gels per hour depending on your weight. For many, this amount of energy gel causes gastric distress, and therefore, other methods may be used in conjunction. Eg. Energy gel plus electrolyte drink.

Another important point to note is that during a longer duration event, fuelling needs to start from the beginning. If you wait until you feel you need it, the chances are it will be too late, as you will always be playing catch up, plus, your stomach may reject the sudden high sugar concentration. Another way to ensure you are well fuelled for a training session is to carb-load.


In general, carb loading is used for any important competition. The more glycogen in your muscle stores, the less your body will have to use the slower method of getting energy from fat stores. So, if you want to perform your best, even in shorter events (5k and 10k) a mini-carb load may be appropriate. You may also want to factor in carbohydrate consumption around your more intense training sessions.

If you are going to use carb-loading ahead of your important races, it is crucially important to practise before, so that you can identify what foods work for you, and what foods don’t work for you.

The aim of carb loading is to fill your liver and muscle glycogen stores so that they are available during the race. This allows you to run for longer before they become depleted and you could be forced to slow down. The idea is that your diet becomes much higher in carbohydrate and you reduce the fat content, so that you can eat the extra carbs without feeling bloated. This is why biscuits, cakes, pizza are not good options for carb-load days. Glycogen is stored with water, so you need to ensure you are consuming more water as well.

An example carb-load day may look like this:
Breakfast: Porridge and a banana
Snack: 4 rice cakes, a handful of jelly babies and some squash to drink
Lunch: Jacket potato with tuna
Snack: Flapjack and some squash to drink
Dinner: pasta with a tomato based sauce
Snack: Jam on toast

For a half marathon, try carb-loading for 1-2 days, and for a marathon, try 2-3 days. Personally, I find that I do need to add some lean protein – and tuna with my lunchtime jacket potato does the trick.

This day may look very unhealthy with the lack of fresh fruit and veg. This is designed to get maximum glycogen into your muscles without causing gastric distress during the race. We therefore have very little fibre in this carb-load diet. White pasta, white bread etc. This is a guideline, but the point is that whatever carb-load you are doing ahead of the marathon, you have practised previously, either ahead of one of your build up races, or in advance of one of your long runs.

Race Day:
Practise on your long runs your race day nutrition strategy that will involve a regular carbohydrate intake from the start of the race, to prevent the onset of ‘THE WALL’. See above for long run strategy. Once you have figured out what works for you, stick to it. This may be 1 jelly baby per mile, or an energy gel every 30 minutes, or some combination of these strategies.

After Running:
A snack that delivers approximately 50g of carbohydrate within 20 minutes of finishing your run. This is ideally a snack that contains protein too, as this will help with muscle repair and the re-filling of your glycogen stores. We are looking for approximately 20% protein: 80% carbohydrate. An ideal snack is 500ml low-fat chocolate milk. Another example is peanut butter on wholemeal toast with a banana and some honey.

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Angela Isherwood

Angela Isherwood is the founder of I Run Success
She is a REPs Level 3 Personal Trainer, a Run England Running coach, and a multiple marathon runner. She is a London Marathon Good for Age runner, a Boston Marathon Qualifier, a parkrun Run Director and Trainer for Goodgym Colchester.

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