How Carb Loading Affects Calories and Race Performance
Last weekend I ran the America’s Finest City half marathon as a tune up race for the Chicago marathon (which is only 8 weeks away now!).
This was my 6th time running AFC and I’m excited and proud to say that I ran my fastest time EVER! At age 42, I beat my26, 27, 29, 36, and 40 year old self. It feels REALLY GOOD!!
The course is notoriously hard – rolling hills to start, a fast downhill at miles 3-4, flat out and back with views of downtown San Diego, and then a brutal 2 mile climb into Balboa Park from miles 10.5-12.5. And it’s always hot- this year it was 85% humidity and 70 degrees at the start.
My Half Marathon Tune-Up Race Goals
Besides running my fastest time, I had 2 other goals for this race:
- Practice race fueling
- Practice a carb load
Practicing Race Fueling During a Half Marathon
While we’re training, it’s pretty hard to simulate race day – you won’t run at race pace for 26.2 miles in training, and even the most advanced marathon plan won’t have you run at marathon pace for over 14 miles. So the half marathon tune up is a great opportunity to practice taking gels during race effort. I crushed this – getting in 65g/hour.
The Sneaky Thought I Had During the Carb Load
Carb loading is one of the only times I track what I eat, because I find it really hard to get in the extreme amount of carbs you need for a carb load without being very intentional. My carb load goal was 520g, which at my weight of 65kg is 8 grams of carbs per kg.
Considering an English muffin is 24g of carbs…
IT’S A LOT of CARBS.
But your body needs it.
Why Carb Loading Requires More Carbohydrates
One of the biggest mistakes people make during a carb load is eating too much fat and protein. The reason you don’t want to eat so much protein and fat is that you will physically get too full to eat all the carbs you need. Plus, if you don’t adjust protein and fat down, you’ll end up eating a pretty large amount of calories in a form you don’t necessarily need.
What I Ate During My Carb Load
Well, I did exactly that. I had my usual 3 eggs & oatmeal at breakfast and leftover Costco pizza for lunch (so much cheese, which is why its so good). I had fruit & veg – banana & apple but have to limit fiber before races. I put butter on an english muffin and peanut butter on my bagel. Despite 2 cups of OJ and some Tailwind, by 4:30 PM, I still had 200g of carbs to eat, and not much room for anything else.
But a pasta dinner and some gummy candy got me there. And after I hit my 500g+ goal, my total calories for the day was over 3,200.
Since my only workout that day was a 30 minute shake out run, and I’d tried to stay off my feet, I was in a calorie surplus of over 1,000.
Why Extra Calories During Carb Loading Aren’t the Problem
But here’s the thing – even though I KNOW better and coach female runners on, I didn’t like seeing that calorie surplus.
What did this exercise remind me?
First, that no matter how far you’ve come, you can still have unhelpful thoughts about calories and food.
And second, this is why I help women move AWAY from calorie counting and macro counting. Not because I am trying to get you to eat in a calorie surplus (in Run Fuel the goal is a small deficit to create fat loss while fueling running) – but because you don’t HAVE to track to lose weight, and it can actually backfire for runners trying to hit a certain calorie goal when one day is a 5 mile run and Saturday is a 12 mile run.
Why Calorie Counting Can Backfire for Runners
While yes, sometimes it can be helpful & informative to count carbs or protein or fiber to see where we’re at (in fact we do this in step 1 of Run Fuel for just 2 days), actually counting everything I ate was not only time consuming (and likely still inaccurate since even in controlled settings studies show people underreport calories consumed by 20%!), but it wasn’t putting me in a good state of mind.
How Carb Loading Supports Race Performance
As women who experienced the diet culture of the 90s and early 2000s, we’re conditioned to think fewer calories is better. But it isn’t always better.
Do I eat pizza & gummy candy every day? No. Most days I eat a lots of fruit, veggies, whole grains, greek yogurt, tuna, and things like beans and lentils.
On this day, my body NEEDED those 1,000 extra calories, stored as glycogen to bust out an incredibly strong half marathon and practice for my future carb load. Not only did I run my fastest time, and sprint to the finish, but my legs felt pretty good during my cool down. That wasn’t going to happen with low carbs.
Why You Shouldn’t Cut Carbs After a Carb Load
After the race, I didn’t cut back on carbs to “make up” for the excess the day before – in fact, I continued to eat carbs to recover, just ones with more fiber this time.
Your performance fueling doesn’t have to clash with your aesthetic goals – one carb load won’t make you gain 3 pounds of fat (even if the scale is up on Monday after a race, it’s likely water related to inflammation!).
So, eat those carbs when it’s time.
Happy running,
Nicole Dobransky
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