Carbs have widely been recognized as your body's #1 source of fuel. But lately, more people have been coming out in favor of fat as our bodies' primary fuel source. Fat literally contains more energy: 9 calories per gram compared to carbohydrates' 4 grams, but which is better for performance? We have both sides of the debate.

A Case for carbs 

Carbs provide the fuel for muscle contractions, making it the single most important nutrient for energy, especially during workouts. Once eaten, carbohydrates breakdown into smaller sugars like glucose that get absorbed and used to fuel those contractions. Any glucose not used right away gets stored in the muscles and the liver in the form of glycogen for use later. Once these glycogen stores are filled up, any extra carbs gets stored as body fat.

Glycogen is the source of energy most often used during intense bouts of exercise because it is immediately accessible. It is also used to metabolize body fat for fuel during longer, lower intensity exercise.

Carbs also protect your muscles from being metabolized during exercise. If there are not enough carbs present in your system, your body's second choice is to use protein to break down into glucose for energy. But because the primary role of protein is to build muscle, bone, skin, and other tissues, relying on protein for energy by failing to consume enough carbs limits your ability to build and maintain body tissue, while putting major stress on your kidneys.

Carbohydrates also fuel the central nervous system (CNS) and brain. Running low on carbs can effect concentration, memory and mood.

Sure, carbs get a bad rap, but it's because the sad fact is that in today's society, carbs are so cheap, processed and readily available that people consume them in excess causing weight gain. But if you fuel your body properly with just enough carbs stored in your tank, they are essential to fueling your workout right.

A case for fat

Your body uses carbs as fuel, but thinking they are the best source and living in fear of running low is keeping us under-fueled and overweight. If we go back to the beginning of man, fat is the preferred fuel of the human metabolism and has been for most of human evolution. It is up to us to get back to basics and retrain our metabolisms.

Humans actually only need very small amounts of glucose, and most, if not all, that you need is provided by the liver. An athlete has enough fat to fuel their body to run over 100 miles compared the 20 miles they can run with the carbs stored in your system, making your fat tank a lot bigger than your carb tank. While carbs are what your body uses first, this isn't natural, and is a product of our cheap-and-easy food lifestyles. We should be retraining our bodies to use fat for fuel since evolutionarily we are carnivores who love to eat fat.

Carbohydrate intake is a huge factor in determining body composition and excess glucose from consuming too many carbohydrates, especially from processed grains and sugars, is the primary cause of obesity and obesity related diseases. Therefore, if you limit your carb intake to just what you need, and no more, you can literally reprogram your body back into the fat burning machine you are supposed to be.



Carbs facilitate the burning of fat, and low carb levels are in fact associated with extreme fatigue and difficulty concentrating so there is no doubt eating enough carbs is vital for your health and energy levels. But thinking that packing your system full of carbs if the best way to fuel your body is selling your performance short an is a recipe for weight gain. 

by Kelly Turner

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