Carbs are King for Everyone, Pt. 1 of 2
Updated: Oct 18, 2019
The one theme you will read again and again in these articles is you will be a better athlete if you eat a more plant-based diet. One of the many reasons is the specific makeup of plants, in particular what macronutrient is found in abundance from plants.
In athletics, what factor is the number 1 limiter of intensity, duration and time to fatigue? And if we could, wouldn’t we want to focus our attention on this limiter to ensure optimal performance? Well, luckily we can! The answer is carbohydrates...All day!! With so much emphasis on protein these days for the athlete and average lay person, one would assume that protein is the limiting factor in our activities. That is not true. Like I spoke about in the first 3 articles, protein is not a significant energy source during exercise or inactivity and is not necessary to consume in any significant quantity during competition. Protein has nothing to do with energy before, during or after activity. Don’t get me wrong, post exercise consumption of protein is very important, but during exercise, carbohydrate consumption is critical and is the limiting factor that could make the difference between finishing the race and placing on the podium.
...there is some historical evidence that our human ancestors consumed very little carbohydrate and survived. However, when considering athletes and the mountain of research demonstrating that carbohydrate is clearly the limiting substrate in athletic performance, it becomes clear that human survival and Human Performance are entirely different matters.
-Dr. Dan Benardot, PhD, RD, FACSM
In the world of aerobic exercise, carbs are king. Their primary role; energy for working muscles, including the brain and the heart. Carbs are mostly broken down in the stomach but are even absorbed through the mucosal lining of our mouths in small amounts. After they are consumed and are in the stomach, the sugars are transported for storage to 3 main locations. Glucose can hang out in the blood for immediate use and this is what we measure when diabetics take their blood sugar/glucose measurements. The blood stores approximately 5g of glucose for healthy adults . Glucose can also be stored in the liver as liver glycogen, approximately 90g. Third, the sugars from carbohydrate foods can also be stored in the muscle as muscle glycogen. When in this form, it is the most readily available carbohydrate for the working muscle. Muscles can store approximately 350g depending on the size of the muscles.
Not all carbs are created equal though. In this country, not only are we protein-centric but we are carb-phobic. We’re afraid of all carbs because we think they lead to weight gain. As you will read a bit later, carbs do lead to a form of weight gain, but it’s because carbs are stored with water, and carbohydrate and water molecules have mass. The other way people think carbs make you fat is by converting to triglycerides, or body fat. Truth be told, all macronutrients can be converted to fats within the body. But out of the 3 macros, it is much more difficult to convert dietary carbs to body fats than it is dietary fat to body fat. The body wants to burn carbs for immediate energy and store fats , p.431]. However, even with this in mind, carbs differ from each other in big ways. My usual analogy is that there’s a huge difference between carbs from pizza and carbs from sweet potatoes. Do both contain carbohydrates? Yes. But they also have a lot of other things including very different amounts of proteins, fats, fiber, vitamins and minerals that should make sweet potatoes a staple and pizza a rare treat.
Another important distinction is between carbs and fats and which macronutrinent the body wants to use for energy production. Very broadly, carbs and fats are both used as energy sources within the body. In order to use calories on a cellular level for muscle contraction, our bodies have to convert either fat or carbohydrate into Adenosine Triphosphate (ATP) which can then be used as energy within the muscle cell for contractions. The process of converting carbohydrates or fats to usable ATP is a process that takes a finite amount of time. And the critical point to remember is the amount of time to convert fats to ATP versus carbs to ATP is not the same. This process of converting fat calories into usable ATP takes longer than it does for carbohydrate molecules. Because of this, carbs are the preferred energy source when competing in high intensity exercise. Benardot writes that when exercising at high intensities, ATP must be generated quickly and the higher the intensity, the faster ATP must be regenerated. For example, when you hit the metaphorical gas pedal and ask for immediate and high intensity energy to distance yourself from your competition or bridge to the leader of the race or put in a high intensity sprint, you want there to be an instant release of energy and rapid regeneration of the used ATP. This is where we need carbs. Carbs are a critical fuel for athletes because they can more efficiently create ATP per unit of oxygen than from any other fuel .
Fat is also an important energy source and as the intensity of the exercise decreases, and as our need for high amounts of ATP production decreases, fat makes up a larger proportion of energy demands. But if you’re reading this and you want to be competitive in triathlons, cycling, swimming or any sport where you are competing against other athletes, you need to be eating carbs and a lot of them. Future articles will cover fats more in depth. There is a surprising and ill-founded call for endurance athletes to consume more fats for a more stable and larger energy source. For many reasons, including the ones outlined in these articles as well as dozens of books and studies, for short term athleticism and long term health and chronic disease prevention, fat loading, ketosis and/or deriving the majority of energy production from fats is not recommended. Benardot agrees “there is some historical evidence that our human ancestors consumed very little carbohydrate and survived. However, when considering athletes and the mountain of research demonstrating that carbohydrate is clearly the limiting substrate in athletic performance, it becomes clear that human survival and Human Performance are entirely different matters”. 
Athletes that choose ketosis have to slash their carbohydrates to almost zero. The difference in calories is made up by fats and some proteins, mostly in the form of animal products because these groups are inherently high in fat and protein. Additionally, ketosis is a physiologic state of survival, not a state of health or vigor. From an evolutionary lens, ketosis is a state that the body goes into to survive a famine or a time where there are no natural carbohydrates anywhere. It shifts into a state of taking fat, not carbohydrates, and converting them into usable energy for the body to use. The body exits ketosis once natural sources of carbohydrates reappear and when the famine ends.
Why do you think Ketosis has gained popularity?
Have you ever tried lower carb diets? How have they worked for you?
The next article is part 2 of 2 on carbohydrates where you’ll learn about carbohydrates before, during and after competition.
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