ACSM Clinical Exercise Physiologist (CEP) Practice Exam - 2026 Prep & Study Guide

A characteristic difference between running and walking is the presence of a period of nonsupport during running. In walking, there is always at least one foot on the ground, which provides stability and support throughout the entire gait cycle. However, in running, there is a moment when both feet are off the ground, resulting in a distinct phase of nonsupport. This phase is crucial as it differs from walking mechanics and allows for the greater propulsion and speed associated with running.

Understanding this characteristic helps to differentiate between the two activities in terms of biomechanics, energy expenditure, and speed. While increased speed, greater energy expenditure, and reduced knee flexion are often attributed to running as well, the defining feature that clearly separates the two is the nonsupport phase, highlighting the unique mechanics of running compared to walking.