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Carb Loading with Dr. Rae

The Calgary Marathon is fast approaching! As you start to settle into that final week of taper and dial in your nutrition before the big day, the idea of carb-loading may have crossed your mind.

Carb-loading is a popular strategy within the running community as a means to maximize glycogen stores before race day. Glycogen is the stored form of glucose, which is our body’s preferred fuel source during moderate to high intensity exercise such as running. We produce glycogen when we eat adequate amounts of carbohydrates and regularly train. As conditioned runners, we have a baseline of glycogen stored in our muscles and liver that can support us for about 90 to 120 minutes of moderate to high intensity exercise. The goal of carb-loading is to super-fill these glycogen stores so that we can run for a longer period of time without running out of energy or hitting the dreaded “Wall”.

So... how and when should you fill your glycogen tanks? Carb-loading can be confusing, many exercise physiologists have developed different methods over the years. This is why you may have heard varying advice from fellow runners or coaches. Here’s the simplest and least risky method.

Carb-loading can start during the final week leading up to your event. Some sources suggest beginning after your final “longer” run commencing taper. This is because the body is the most receptive to storing glycogen after its stores have been tapped. Ensure that you refuel after your runs in the week leading up to your race with simple carbs rather then more complex, within 15 minutes regardless of the distance or intensity.

After your final “longer” run you can begin to focus on simple rather than complex carbs. Around 2.5 to 3 days before your race, aim for around 8-10 grams of carbs per kilogram of body weight per day.

The amount of carbs you need for the next few days may feel daunting. But there are a few ways to sneak them in throughout the day without feeling stuffed. One way is to reach for high glycemic foods during this time. High glycemic foods are quicker source of carbohydrates, lower in fibre, which fills us less and cause fewer digestive issues. Sources are potatoes, white rice, breads, pastas and most fruits. Carb loading gives the green light to indulge in a serving or two of sugary liquids such fruit juices or sports drinks which won’t leave you feeling full. Other tips include adding a serving of fruit to each meal and snacking on dried fruit and pretzels as these are all easily digested and low fibre. Committing to eating small meals or snacks every 2-3 hours can make the process easier. Hydration is important too as muscles require water to synthesize glycogen.

Carb loading can challenge one’s beliefs of what healthy fuelling should be. Most of us are used to diets full of fresh fibrous vegetables, fruits, whole grains and protein sources. It’s helpful to remind yourself that it’s only for a few days, it will pay off and then you can return to your balanced diet after the race.

Some athletes report feeling stiff and bloated during the load. This can cause anxiety about running heavy or de-conditioning after a few days of rest and throwing down carbs. Embrace the bloat! This is totally normal and a good sign that you are carb loading right. You’re storing extra water as a result of storing extra glycogen and your body is going to need that extra water and carbs for your big effort come race day.

It’s important to note that the information in this article is not a substitute for medical advice. Working with a nutritionist is the best way to ensure that your unique nutritional needs are being met.

Now go a slay your race!

Contributed by Dr. Rae Laberge

DTCM, RAc, CHN Holistic Nutrition Consultant

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