Low-carb diets have been trending for a long time, however they aren't for everyone, and they certainly aren't for athletes. Read on to learn more about why you need carbs!
Whether it's your great aunt who keeps posting about it on Facebook, your friend, or your teammate, we all know someone who went "keto" or "low-carb" this year. Maybe you even tried to cut back on carbs by using a piece of lettuce instead of a burger bun, or swapping pasta for zucchini noodles. Don't get me wrong, lettuce and zucchini noodles are great and certainly have their place in a balanced diet for athletes, BUT they shouldn't be replacing precious carbohydrates.
So why have carbs always gotten such a bad rap? What did carbs ever do to us? Really, the question should be what did we do to carbs to create this mentality. The answer: we processed them! It is true, research has shown that diets high in process carbohydrates can lead to diabetes, cardiovascular disease, obesity, and other health conditions. But you know what else does? Lack of exercise, a diet low in fruits and veggies, and genetics!
Although certain types of carbs can play a role in poor health, we have to remember that they are not solely responsible for any health condition. Cutting out processed carbs will not improve your health if you don't also exercise and eat a balanced diet.
So that being said, we have to remember that the carbohydrate needs of the general population are VERY different from highly active athletes. This demonizing of carbs has to do with the general population, NOT athletes!
What Even Are Carbs?
Carbs are not the enemy! They serve as the main source of fuel for your body and brain, and are a necessary part of an athlete's diet.
Carbohydrates are made up of chains of three single sugar molecules: galactose, fructose, and glucose. You may recognize a few of these words, specifically glucose and fructose. Most carbohydrates, regardless of their source, are ultimately broken down into glucose (sugar). It's this molecule that travels in your blood and provide energy to your working muscles and to your brain.
That doesn't mean that all carbs are created equal. A piece of whole grain bread that breaks down into glucose isn't the same as a piece of candy. But we'll get to that later!
How do we use carbs?
Carbohydrates are stored in the body in two ways.
Muscle glycogen is the main source of carbohydrates in the body, followed by liver glycogen, with blood glucose being the smallest. Muscle glycogen and blood glucose together provide about 50% of the energy you need for moderate-intensity exercise (most runs) and about 65% of the energy you need for high-intensity (think 1k repeats or 400's with short rest).
Liver glycogen is mainly broken down over night or over the course of the day to help maintain blood glucose. During rest, most of your blood glucose is used to keep the brain running and keep the central nervous system functioning (like your lungs moving and your heart beating).
So exercise aside, you can see why the body needs carbs! If you don't eat enough carbs, your body has to find other ways to create glucose to keep you alive. How does it do that? By breaking down muscle to turn amino acids into glucose.
What happens if I don't eat enough carbs?
Running will become really, really hard. Not eating enough carbs can cause:
Low energy levels
Difficulty building/maintaining muscle mass
Increased risk for injury
Difficulty maintaining an effort during runs or that "hitting the wall" feeling
How much of my diet should be carbs?
For a runner, your carb needs range from 6-10g/kg per day. For a 120lb athlete, that's 330-550g of carbs per day! Here is approximately how many grams of carbs are in specific foods:
1 cup of berries - 15g
2 slices of bread - 25g
1 banana - 30g
1 medium potato - 30g
1 cup cooked pasta - 45g
1 cup cooked rice - 45g
1 cup cooked beans - 45g
1 bagel - 45g
Where should I be getting my carbs?
Like I mentioned earlier, not all carbs are created equal. The majority of the time, we want to focus on what are called "complex carbohydrates". These are sources of carbs that have more fiber and nutrients because they aren't as processed. Examples include potatoes, beans, peas, lentils, brown rice, whole wheat bread/pasta, oats, and fruits.
However, simple or refined carbohydrates (the more processed form) can certainly serve a purpose in an athletes diet. Some examples include white bread, fruit juices, and sports foods like Gatorade and GU. These types of carbohydrates are more easily digested, so they are actually a better option than complex carbs for pre-workout to help reduce risk of GI issues (for example white bread rather than wheat bread).
Let's not forget about the desserts like ice cream, cake, cookies, and pastries! Although we don't want to get all of our carbs from these sources, it's perfectly fine to enjoy these foods in moderation along with a balanced diet! For example, a pastry at breakfast with a veggie scramble and side of fruit.
When should I eat my carbs?
The timing of carbs is another important aspect of an athlete's diet. There are 3 main windows to focus on when it comes to carb intake:
Pre-Workout: eating before workouts helps top off energy stores, which can boost endurance and prevent bonking. Aim for around 45-60g of carbs, and this would be the time for the simple carb sources! For example, two toaster waffles with maple syrup. If you aren't used to eating before runs, start small (such as a glass of orange juice). Either way, you should ALWAYS eat before workouts!
Post-Workout: your body is the most efficient at replenishing muscle glycogen within 1-2 hours of your workout. If you're able to have a meal in that time frame, that is usually preferred (whole foods first!). But if not, recovery shakes WITH carbs (not just protein powder) is ideal. This well help boost recovery so you can bounce back faster! Some examples include scrambled eggs with toast, a smoothie made with Greek yogurt and frozen fruit, or a recovery shake like Skratch Labs Recovery or Momentous RedShift.
During the day: this is when those complex carbs come in! Get a wide variety of complex carbohydrates during the day to not only help you meet your carb needs, but also to make sure you're getting enough nutrients like B vitamins, iron, magnesium, and fiber!
What about the research that says low carb diets help endurance athletes?
During exercise, you are always burning a mix of carbohydrates and fat. It is true that some studies have shown a low carb, high fat diet can make you more efficient at using fat for energy in endurance events (we're talking ultra marathon distances). However, this increase is very small and is not enough to compensate for the decrease in exercise economy due to low carbohydrate availability.
Further, there is a very large body of research that has shown training and competing with high carbohydrate availability does increase performance, while studies done on low carbohydrate availability are most mixed/inconclusive or have shown no effect on performance.
For anyone interested, here is a great review article summarizing some of the current research:
Hopefully this has helped debunk some of the misinformation you've heard about carbs and that I've convinced you that as an athlete, you need carbs! This information is all based on research done on athletes, and one thing is for sure: inadequate carb intake negatively impacts performance. So eat the whole banana, use a burger bun, and have more than 2 pieces of bread in a day. Your body will thank you, and you will see the results in your performance!
Have more questions about how to incorporate this advice into your own fueling strategy? Fill out a contact form on my website to see if we can work together to find the best approach for you!