What is the primary consequence of excessive vertical body movement while running?

The primary consequence of excessive vertical body movement while running is wasted energy. When a runner excessively bounces up and down, it leads to a disorganization in their stride and inefficient mechanics. Instead of propelling themselves forward, a portion of their energy is used to lift their body upwards rather than moving horizontally. This results in less effective energy use and can lead to fatigue more quickly, as running efficiency is compromised.

Maintaining a low center of gravity and minimizing vertical oscillation helps runners to conserve energy and improve their overall performance. This is why experienced runners focus on a more fluid, forward motion that optimizes their energy expenditure.