Thread by @Mangan150

"Earn your carbs"

What does this mean?

The human body can store carbs as glycogen in muscles and liver, but storage capacity is limited, ~2000 calories worth.

Glycogen is made of long, branching chains of glucose.

This is the same glucose that's in the blood.

Carbohydrates are also made of glucose. Some carbs, such as sucrose (table sugar) are made of glucose and fructose.

The function of glycogen in muscles is to provide energy for high-intensity exercise - fight or flight.

When you're at rest or doing low intensity activity such as walking, you burn mostly fat.

Humans have vastly greater storage capacity for fat.

A typical person could go for weeks without eating, merely using energy stores from fat.

But muscle glycogen is made for emergencies, like fleeing a mountain lion or fighting an attacker.

Or for high-intensity exercise, such as sprinting or high-intensity strength training.

If someone never exercises at high-intensity, or fights or flees, glycogen is never depleted

Then, when carbs are consumed, and glycogen stores are full, the carbs are turned into fat, and stored.

Someone who does high-intensity exercise depletes glycogen and therefore can eat some carbs with impunity.

Someone who never exercises in this way turns carbs into fat.

Typically a person who exercises at high intensity doesn't *need* carbs, unless they do this activity long enough and often.

But they tolerate them better.

Someone who does none of this activity will tend to store carbs as fat.

Earn your carbs.