Big Strides, Big Lungs
Because of their endurance level, horses are known to be able to sustain long periods of effort without getting any rest. This really amazing ability is made possible with their humongous lungs which measure over a meter. Big lungs mean more surface area for oxygen absorption.
Both humans’ and horses’ lungs have a long list of similar characteristics. However, their capacities are pretty distinct to a certain degree. Humans at rest can inhale roughly 0.5 liters of air with each normal breath, while a horse at rest can draw in approximately 5 liters of air with each tidal breath. Impossible? No. Horses were built to do heavy work, so their lungs need to endure more stress than ours.