Carbs & Running- Everything you need to know

 How to successfully carbo-load:

What we will cover:
glycogen storages
complex carbs
simple carbs

Glycemic index

First let’s note the cardinal rule of running:
Never try anything new on race day.

Why Do Runners Carbo-load?

The reason why people ‘carbo-load’ is to restore your glycogen storage levels in the muscles. Glycogen storages get depleted over time during your training. The more you run & the longer you run, the more depleted your glycogen storages are.

How are Glycogen Storages Restored?

When we take rest days and reduce mileage [taper] while maintaining your usual diet, these storages will slowly build back up to normal. To build up glycogen storages more effectively, athletes will increase the ratio of carbohydrates they are consuming 4-7 days before the race. It takes time for the storages to refill to normal, so it is best to span this process out to 4-7 days before the race.

 What is a ‘Glycogen Storage’?

The glycogen storages will NOT make you faster. The glycogen storages only come into play after going over 90 min of activity– for this reason you do NOT need to carbo-load before 5k-10k distance races. Glycogen will help you run longer & race without hitting a ‘wall’/running out of internal fuel during the race (given you run a smart race).


Simple carbs – take DURING or the race or right before the race or immediately after because they can be utilized right away.
Examples: baked potatoes, Soda, Gatorade, corn, white bread, white pasta, muffin, donughts, cake, candy, chips
Simple Carbs can be found on the race course of ultra marathons because they give your body the fuel it need immediately into the blood stream
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These are things ultra marathons really eat on the course. You might have wondered, “why do they eat junk food when they are running”- now you know!
How much should you eat?
You will not be running as much the taper week, so no need to increase the amount of calories you are eating. Rather, focus on getting more calories from complex carb sources. 
I believe in intuitive eating. You should eat when you are hungry. Intuitive eating is best for people who watch their glycemic indexes in food.


Carbohydrates are extremely important for runners throughout their training cycle, and become even more of a cornerstone in nutrition during the taper. Most runners will benefit from properly topping off glycogen stores in the days leading up to endurance events, especially those that will take at least 90 minutes hours to complete.
All carbohydrates can be useful to carbo-load during the taper, with simple carbohydrates like white rice, pasta, white breads, fruit, milk, sweets, and carb-containing sports drinks filling up glycogen stores most efficiently when compared to complex carbohydrates like whole grains, legumes, and veggies. Simple carbohydrates also typically contain less fiber and digest quickly, making them a good option for runners wishing to avoid GI distress on race day.
Since eating enough carbohydrates to properly carbo-load may be challenging for some runners, incorporating simple carbs and allowing more of the food eaten in the days leading up to the race to come from carbohydrate rich foods may be helpful strategies. This can (and should) also be practiced during training!

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One thought on “Carbs & Running- Everything you need to know

  1. […] 90+ min – add in additional carbs the 48 hours leading up to this run. Focus on getting complex carbs that will break down slowly like sweet potatoes, whole grains, quinoa. Don’t fill up on simple carbs like white bread or junk food- that is not carbo-loading. HERE IS A BLOG ABOUT CARBO LOADING 🙂 […]

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