Carbohydrate Intolerance and Insulin Resistance are huge topics in the health, wellness, fitness and nutrition industries right now, and rightly so. In the past, elevated blood cholesterol was thought to result from diets that contained high-levels of fat. Today, in order to ‘lower cholesterol and inflammation, we're finding out that it's much the opposite. It is now being researched and believed that inflammation is what causes cholesterol to become trapped in the body creating negative health side effects, disease and lack of performance.
While inflammation is that dirty little word we all hate to say, we need to realize that it’s the body’s natural defense mechanism to foreign substances in the body. Thus, our typical diets, high-carbohydrate diets, which contain large amounts of processed food, are creating chronic inflammation. So what can we do about it?
Getting back to you, the athlete/athletic individual, who takes pride in their health and are looking for the best options to improve not only performance but their overall well-being, I’d like to help you to begin understanding the high-carb vs low-carb differences and navigating the path that is right for your own health and well-being.
High-Carb Vs Low-Carb Diet
In the past, most athletes followed an obligatory need for high-carbohydrate diets. But despite this being the majority, one size doesn’t fit all. With high carbohydrate diets, insulin resistance is cultivated which triggers the brain to become dependent on carbohydrates as it's dominant source of fuel. While this has worked for a variety of different athletes, when it comes to CrossFit, we’re pushing past thresholds and need to dig deeper into the gas tank. Insert – low-carbohydrate diets.
The human body is physically unable to switch quickly between the use of carbs to fat as the main source of exercise fuel, so once the carbs are depleted, your body is unable to aid performance with fat alone. The good news? You can train your body with your diet, to burn body fat, turning glycogen and blood sugar into secondary fuels when you run out of the former. This not only increases performance but aids with increasing lactic/anabolic thresholds and vo2 max.
Therefore your endurance will increase, resulting in more training, faster recovery, and better results.
Four Benefits of a Low-Carbohydrate Diet
- Low carb nutritional guidelines and adapting to them fuels the body’s ability to use saturated fats for fuel that in turn allows for higher intakes of fats (including saturated fats) without risk.
- Low carb living creates a reliance on body fat, not just at resting, but also during exercise. This creates a lesser dependence on muscle glycogen and less of a need to overload yourself with carbs post workout.
- Low carb lifestyles are anti-inflammatory. Your body naturally will create less oxidative stress during exercise and promote naturally faster recovery between training sessions.
- Low carb/carbohydrate restricted diets can be advantageous for CrossFitters, lifters and endurance athletes alike for improving performance, seeing desirable body composition changes, and power-to-weight ratios.
While low carbohydrate lifestyles are not ideal for every athlete it is extremely desirable for others.
Fuel from Carbs or Fuel from Fat?
The two primary fuel sources our bodies use for energy are carbohydrates and fats. Ideally, you want to use a little of both, or all of one and then the other. This, unfortunately, isn’t the case, like many carb loaders believe. Adenosine triphosphate (ATP) is the chemical energy that causes muscle fibers to contract and produce force.
Higher intensity exercise, like CrossFit, demands a serious increase in the availability of ATP. But guess what? Humans don’t store ATP and we certainly don’t eat ATP in appreciable amounts, so ATP production during high-intensity requirements has to come from another source of energy (carbs & fats). See where I’m going with this yet? Ok – here it is:
In high-carbohydrate diets, the more carbs available the more carbs the body is going to burn. The downside is that the body is so busy using carbs for energy that it shuts down access and use of it’s biggest fuel reserve - BODY FAT.
Do All Athletes Need High-Carbohydrate Diets?
While carbohydrates are the preferred fuel for athletes, it isn’t always the best fuel. Carbs are not stored in the body in high quantities as compared to fat. Fatty acids are stored in the body as triglycerides making up nearly 85% of adipose tissue! Comparatively speaking, in order to burn carbs, the body metabolizes glucose to make ATP and stores glucose in decent amounts of glycogen in skeletal muscle and the liver. The average glycogen store is 400-500 grams which really isn’t that much.
Fat cells have a huge capacity to store fat whereas carbs do not. Fat storage is an impressively efficient form of stored energy that can be mobilized quickly when blood insulin levels are low. Even in very lean CrossFit or endurance athletes, the total amount of energy stored as fat can be close to 20x the max level of carbs stored (like, WOAH!).
To put it all into perspective, you basically can choose how your body utilizes energy based on your diet. CrossFit intensive exercises have the capacity to deplete glycogen reserves in just a few hours, whereas when an athlete is accustomed to burning primarily fat, an athlete has enough fat to fuel several days of exercise! The difference is huge, and while it is based on your personal needs, there’s a lot of research and positive argument for both.
Is a Low-Carbohydrate Diet the Same as The Keto Diet?
Yes, and no. Alright ketobros, hold your horses. Simply put, low-carbohydrate diets modify one profile of macronutrients whereas the Keto Diet modifies all three macronutrient profiles. It also depends on how low the carbohydrates are and everyone’s definition of low carbohydrates are different. So, let’s break it down by numbers.
LOW CARBOHYDRATE DIET
Consuming less than 30% of calories from carbs
Consuming less than 5-10% of calories from carbs
About 45-130g carbs per day
About 20-35g carbs per day (definitely recommended no more than 45g per day
Typical American Dietary Guidelines set in 2010 recommend 45-60% of calories come from carbohydrates
Under 50g of carbs per day promotes keto-adaption in a few weeks (first voiced by US Army surgeon & Arctic explorer Dr. Phinney in 1983 watershed study)
There are a ton of reasons why people do CrossFit and exercise in general! They range from recreational to highly competitive, to somewhere in-between, and even up to the professional/elite level. And just as the reasons for exercising are different, so are the reasons why you might consider adopting a keto lifestyle or embracing a low-carbohydrate lifestyle.
What’s the Difference Between High-Carb and Low Carb Diets?
Fat cells die off intermittently in the body. Good thing right? Well, if you’re preparing for them to die off, then yeah, it’s great! But if you’re dependent on a high-carbohydrate diet, maybe not. The majority of people join a CrossFit Box, Gold Gym, or 24 Hour Fitness or workout in their garage to do what? LOSE FAT. You guessed right! Typically speaking, when someone tries a calorically-restricted diet, with more exercise and less food they might lose the weight but have zero energy to exercise with. Sounds sucky, and it is!
Diets like this only have enough carbs to prevent keto-adaption but not enough to actually give you any fuel for fitness. All that hard work and all you get are a few lost lbs. and a whole lot of compromised workouts, inability to recover, and training adaptations. This is where the big game changer comes in between a high-carb and low-carb diet.
When an individual becomes keto-adapted through a low-carb and/or keto diet, they gain the ability to give their muscles and brain cells optimized access to fat stores. This way you are able to provide adequate fuel/energy for fitness without putting fat cells into storage mode. Instead, fat is readily available for use and you’re able to incite fat loss without the loss of training intensity and performance!
The direct effects of a low carbohydrate/keto-adaption diet change can be seen in power-to-weight ratios, improved body composition, positively sustained fuel delivery and improved prolonged endurance performance.
Break it down by the numbers: for every 10lbs of body fat you may lose, about 8.5lbs of that 10lbs is actual fat whereas the other 1.5lbs is considered to be lean tissue. SO… if you lose 10lbs of bodyweight on a well-formulated low carbohydrate lifestyle, tests will indicate you have actually gained 1.5lbs of lean tissue located somewhere else in the body than in the fat cells.
Don't You Need Carbohydrates to Fuel Your Mind?
Wrong! While this is an extremely complex and highly orchestrated sequence of events requiring the body to change up the various fuel sources for cells in the body, in short, ketones made in the liver are circulated to your body’s muscle and brain as fuel sources. While your body is adjusting to the low carb lifestyle, your body will ease the transition by sending both ketones and fat together as sources of energy to muscles and the brain. But once keto-adaption takes place (usually adaptable 2 weeks to a month), your body at rest becomes dependent on fatty acids during periods of both rest and work.
By distancing the reliance of muscles on ketones, hepatic ketone production is used for other tissues, including the brain. We’ve been taught in common nutrition practices, education and in conversation that the brain can only burn glucose or ketones.
When you switch to a low carb lifestyle, the brain adapts as well and switches its processes to use ketones as it’s primary source of fuel. It’s a beautifully choreographed love scene in the sharing of ketones between the body’s musculoskeletal system and the brain (SCIENCE RULES! [Bill Nye]).
Is A Low-Carbohydrate Diet Right For You?
Maintaining a high-carbohydrate availability in CrossFit and other endurance sports is a struggle! It honestly sucks eating a crap ton of tasteless, non-nutritious foods so that you can perform well and optimize your recovery. It’s time to rethink and challenge what you've been taught to see if a low-carbohydrate diet works for you!
The important takeaway is this: there is no one size fits all diet. If your recovery and performance are sluggish – that’s your body’s way of communicating, that maybe you need to change things up. Ditching your high-carbohydrate diet might be exactly what you need to finally reach your body composition goals. I know it's worked for me!
Switching to lipid fuel sources with selective partitioning of ketones can be revolutionary for CrossFit and endurance athletes alike. The only thing that is standing between you and optimal athletic potential is creating a brief period of adaptation to a low-carb diet and reaping the reward of having full access to your fat stores at both periods of rest and work. Yes – it’s possible! So, what’s stopping you now?