Cellular Respiration: Your Body's Energy System

Your body is basically a biological battery that never stops recharging. It is all thanks

to a process called cellular respiration. Your cells take the food you eat, break down the glucose,

and turn it into ATP. Think of ATP as the cash your body spends to do literally

anything, like moving or thinking. Most of the time, your mitochondria use oxygen to print

this cash efficiently. But if you sprint and run out of breath, your cells panic and switch to a

backup mode that makes lactic acid. That burn in your legs is just your cells screaming

because they are running on fumes.