Best practices for food timing around training sessions Part 2 - Food timing during exercise

What to eat during your race is a question I get asked about a lot, and is discussed regularly in the awesome MX Endurance facebook group. We recently discussed which foods are best choices for before physical activity, in particularly endurance sessions.  Today, we’re talking food timing during exercise.

Why eat whilst exercising?

When participating in endurance events, or training for one, our bodies are using up glycogen as our main fuel source. Glycogen is carbohydrate in it’s stored form. Carbohydrate is the main source of fuel in endurance exercise with enough to last around 90 minutes of activity before you really need to top it up (less if your work rate is higher).

Eating while exercising becomes more important the longer your race.

To keep it simple, you eat your gel, or sports drink or bar, and it is digested to glucose. This then moves to the muscle to be stored as glycogen, and then converted to a substance called ATP. ATP is what your muscles use for energy so they can contract and work. The time it takes for the food you’ve eaten to digest depends on the glycaemic index and type of carbohydrate. For example, a gel is available for use within minutes due to a special combination of carbohydrate to improve absorption, and a high GI level, whereas your morning porridge will take much longer to digest.

When not to eat

Of course, it is not always necessary to eat during training sessions. If the session is particularly short (less than 60 minutes), or you are purposely doing a lower intensity session to help improve your body’s ability to burn fat, including fasted sessions (sessions where you haven’t eaten) is recommended.

How much is needed?

Recommendations vary between 30-90g per hour in various research studies. If the event is 1-2 hours, 30g/hr is optimal, 2-3 hours and recommendations go up to 60g/h, above 3 hours and the suggestion is 90g/hr. To be really frank, many individuals walk through my door (or answer my skype call!) consuming around 20g/hr, sometimes less than that. And the thought of consuming 90g/hr (around 3 gels worth per hour, depending on brand) can be mildly nauseating.

There is one key caveat though with these quantities; whilst performance seems to go up when consuming carbs in these quantities, this is subject to the gastrointestinal tract’s ability to tolerate these amounts. Feeling well and comfortable is more important than getting that extra bit of carbohydrate in.

Practicing your nutrition plan, and how much you will have multiple times in training, so you have it entirely sorted, and trust it 100% will make life much easier for you come race day.

The other thing to keep in mind is how much the body can use at once. If only consuming one type of carbohydrate, the body cannot digest more than 60g per hour; when different types of carbs are consumed at once, this number increases, due to the use of different transporters.

What to choose?

Gels, sports drinks and sports bars are all popular, convenient choices, and often contain these different types of carbohydrates mentioned previously.

If that’s not your jam, making your own food is another great choices. Sandwiches, wraps, homemade bars, dried fruit are all popular choices.

Some of my favourite suggestions of homemade food include:

-        Vegemite sandwich (yep… I’m an Aussie!)

-        Honey sandwich

-        Jam sandwich

-        Egg wrap

-        Dates

-        Dried fruit

-        Rice bar

A sneaky recipe from me: Nutella and Rice Slice

I make this pretty regularly for some friends who go out on day long bike rides, and it is certainly a favourite! Whilst there are a few variations to this, this provides a great base:

-        2 cups Sushi rice

-        Nutella

-        Salt

-        Tart cherry juice

-        Berries or banana (your choice)

Boil the rice in a mix of the cherry juice and water

Press half the rice into a tray lined with baking paper, to create a 1-2cm thick layer.

Spread with Nutella, then sprinkle with salt

Layer with fruit of your choice

Add rest of the rice and create a top layer.

Place in fridge to allow to set (approx. 2 hours)

Slice up into small bars, and wrap with paper or foil!




Chloe McLeod has had a keen interest in nutrition from a young age due to food intolerances as well as a realization about the important role food plays in an active lifestyle. She has a bachelor’s degree in Nutrition & Dietetics, a master’s degree in Public Health, has received Sports Dietetics training through the Australian Institute of Sport, and has earned qualifications for ISAK Level 1, and is a member of DAA, SDA, and PINES. She is a two-time marathoner, avid trail runner, and also enjoys staying active through snowboarding and Pilates.

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