Energy burned from carbs??

[swoleramon]

Someone just told me "Clinical studies have shown us that you will burn 63 to 68 percent of all calories burned during exercise from carbs, regardless of if you drank or ate anything prior to exercise."

This confused me. What if you are on a low carb diet or what if you don't eat many carbs to begin with??

[MC]

Seems to reason to me that if you are on a TKD or Low Carb diet and you are training hard, that your body would be burning fat, some muscle and what little carbs you do ingest.

[Soldier]

Carbohydrates by definition turn to glucose once they enter the body. This glucose is stored in body tissue as glycogen, which is the primary source of energy for your body. Of course this is an oversimplification, but hopefully you get the picture.

Basically, your body has a number of ways of getting the energy it needs but it prefers certain sources over others. If you have glycogen in your muscles, then that will be the main source of energy. Once that glycogen is depleted it can be replenished if there is more glucose available, or the body can start to metabolize other things like fat and protein (muscle) to use for energy.

Glycogen being depleted in the muscles is the main reason that carbs are consumed during longer duration physical activities such as a football game or running a marathon. Carbohydrates are also the easiest macro for the body to process into energy, and the simpler the carbs the easier it is to digest and use for energy. This is why marathon runners use gel packs that are essentially sugar paste. The easier it is to digest, the quicker it can be used for energy.

[austin.j.taylor]

Originally Posted by swoleramon

Someone just told me "Clinical studies have shown us that you will burn 63 to 68 percent of all calories burned during exercise from carbs, regardless of if you drank or ate anything prior to exercise."

This confused me. What if you are on a low carb diet or what if you don't eat many carbs to begin with??

The word carb is not used in the correct context here. They are talking about burning glucogyn, which is a sugar that your body makes and stores in the liver. Your body makes glucogyn one of two ways, converting carbs that have been eaten, or converting stored fat to glucogyn. When you are low carbing for an extended period of time, like in keto or tkd, your body willingly uses stored fat for energy. It can only do this efficiently for so long before a refeed is needed.

[Soldier]

Originally Posted by austin.j.taylor

The word carb is not used in the correct context here. They are talking about burning glucogyn, which is a sugar that your body makes and stores in the liver. Your body makes glucogyn one of two ways, converting carbs that have been eaten, or converting stored fat to glucogyn. When you are low carbing for an extended period of time, like in keto or tkd, your body willingly uses stored fat for energy. It can only do this efficiently for so long before a refeed is needed.

For optimum performance this is the case, but the body can derive energy from any nutritional source. It'll work with what it gets, or if it gets nothing it'll start to eat itself.

[MikeC]

How do triglycerides fit into all this?

[Soldier]

It appears, from doing a little reading on the subject, that triglycerides are created when there are extra calories taken in that are not needed at the moment. They are a source of energy for the body, but high levels are an indicator of heart disease as they are a type of fat that flows in the bloodstream, and fat cannot be disolved in the bloodstream. Carbs and fats more easily produce triglycerides because they are more easily digested compared with proteins, and insulin resistance (a common problem with those who are obese) also correlates with higher triglyceride levels.

It looks to me like triglycerides, as the standard pathway by which excess calories are stored and then retrieved for later use, are a normal part of the metabolic process, and the reason doctors pay attention to triglycerides is just because of the correlation between higher levels and heart disease.