Here's why:

* Essential for Life: Breathing is essential for survival. Your body needs oxygen to function, and breathing is the process that brings oxygen in and removes carbon dioxide.

* Constant Activity: You breathe continuously, even when you're asleep and completely at rest.

* Energy Consumption: The muscles involved in breathing require energy to function, even at rest. This energy expenditure contributes to your basal metabolic rate.

Other examples of basal metabolism activities include:

* Heart beating

* Brain activity

* Maintaining body temperature

* Cell function and repair

These activities are all essential for life and occur even when you're in a resting state, meaning they contribute to your body's baseline energy expenditure.