Science in Sport – Marathon Nutrition

Following the Tokyo marathon, I didn’t get my fuelling strategy right which impacted my race. So this opportunity to be invited and learn about marathon nutrition from the Science in Sport (SiS) team, came at the perfect time.

I’ve been using SiS products for years but it was a great opportunity to learn more about the range of products you can use pre, during and post training.

The aim of the event was to provide practical marathon training advice and nutrition training. The event was hosted by:

  • Dr. James Morton, SiS Knowledge Director and Team Sky nutritionist;
  • Alan Murchison, SiS Ambassador and owner of Performance Chef;
  • Max Willcocks, SiS Ambassador and endurance athlete.


Fuelling For The Marathon:

Energy for marathon running is provided by a mixture of carbohydrate and fat as fuel. However carbohydrate is the main source of fuel for high intensity exercise.

It’s important to build your carbohydrate intake, to ensure that muscle glycogen stores remain high prior and during the race.

Carbohydrate loading:

Before your race, this can consist of 1-2 days of carbohydrate intake which equates to 8-10g/kg body mass.

The preference should be for high glycemic carbohydrates which increases muscle glycogen storage to a greater extent then lower glycaemic carbohydrates.

Pre race meals should contain a carbohydrate intake of 2-3g/kg body mass.

Please note that carbohydrates intake can be consumed via liquids also.


Marathon Fuelling Strategy:

Some people prefer solid foods, but in my experience having carbs in gel form, is more easily digested and absorbed quicker than solid foods.

The body can only store around 300g glycogen so it’s important to keep these reserves up, as during the marathon the aim is to consume 60g of carbohydrates per hour.

This equates to using 1no. SiS isotonic energy gel for every 20 minutes of activity.

As I learnt in Tokyo you need to focus on electrolytes as well as carbs. Therefore for every 60mins of exercise, this would equate to taking 1no. SiS energy + electrolyte gel and 2no. SiS isotonic energy gels.

An alternative could be to take 3no. SiS isotonic energy gels and consume an electrolyte drink to thirst, which usually equates to 500ml per hour.

Post Marathon or Training Session:

This part of training is underestimated. It’s important to consume the right fuel within 30 minutes post exercise for best results, for your recovery and workouts for the following day.

Firstly getting fluid on board post workout is essential as you would have lost fluid through exercise, and it’s important to rehydrate.

Secondly don’t starve yourself, eat optimally so you can healthy sustain your training schedule. Chicken and salad post workout will leave you fatigued for the next day. Have a plan for your post race meal and hydration. Try to look at getting, carbohydrates, fat, protein and fructose. A basic version could look like a avocado, vegetables, rice, tuna, and fruit. Also plan for snacks.

If your finishing a race or a workout initially use the SiS REGO rapid recovery mix, which is a blend of protein carbohydrate and electrolytes to help muscles recover and rebuild post workout. Before eating solid foods.

Isn’t it better to burn fat over carbohydrates?

There is an alternative idea that you should work on running at low glycogen stores, to burn fat, which is a better fuel source. To a certain extent this is exactly what happens in most training sessions and it definitely does work.

However whilst racing, it’s not the most efficient method to run at your optimum for 26.2 miles.

If you think of it in the same way as putting petrol in a car. Once you’ve burned through your glycogen stores and are down to burning fat, that would be a quarter of tank of petrol. Whereas if you actively were topping up your limited carbohydrate stores, the level of energy would be around half a tank.

A great deal of energy is being expended running a marathon, so it’s a risky strategy running at a quarter of a tank for a considerable time. So for race day specifically it’s important to keep your glycogen store high, to keep your energy stores at balanced level, and to help you run more efficiently.


Final pointers:
Carbs: you can carbo load from 24 to 48 hours before a marathon. Additionally consume high GI foods for better results.

Caffeine: This can help increase alertness and improves concentration, so aim to consume 1no. SiS energy + caffeine gel within 60 minutes prior to when you need it. So this typically would be within the last 10K of a marathon. But if you do consume more, don’t have more than five of these gels per day.

Fuelling: Always be preemptive with fuelling and hydration. Work to find your balance, so your not over or under fuelled or hydrated, as this will negatively impact your race. For recipes check out the book Run Fast Eat Slow or for tailored advice speak to SiS ambassador Alan – Performance Chef.

Elite: Don’t be hung up with the argument, that this only applies to an elite runner and therefore you can skimp on best nutrition practice. The nutritional basics noted relate to everyone regardless of your finish times. Take care of your body and it will take care of you on race day.

The products and further nutritional advice can viewed through the link below.

In the coming months I will be offering more nutritional advice, plus providing information and discount codes so watch this space.


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