How do long legs help canines run over long distances?

Canines are well-adapted for cursorial (running) movement, and their relatively long legs play a key role in this ability.12

The primary mechanical advantage of elongated lower legs is the reduction of weight at the end of the limb. Because a leg functions similarly to a pendulum, minimizing mass at the distal end increases the speed of oscillation, which allows for a more efficient and rapid stride cycle. Furthermore, in cursorial mammals, muscles are typically positioned high on the leg, with only tendons extending downward. This configuration prevents a large mass from being concentrated near the tip of the limb, where its inertia would otherwise restrict the speed and efficiency of movement.34

Combined with digitigrade locomotion—walking on their toes—these structural adaptations enable canines to maintain exceptional stamina, making them highly effective at traveling over long distances. While some breeds have been selectively bred for specific gaits or bursts of speed, the general skeletal articulation of the shoulder, pelvis, and limbs allows most canines to trot or run with significant ease.12