Which statement best describes energy cost trend when walking speed deviates from the optimal?

Which statement best describes energy cost trend when walking speed deviates from the optimal?

• A. It remains constant
• B. It decreases
• C. It increases
• D. It becomes negative

Answer: (C)

The main idea is that energy cost is minimized at a specific walking speed, and moving away from that speed makes the energy cost per distance rise. When you walk faster or slower than the optimum, the body has to do more work per meter to produce movement. At slower speeds, stabilization and limb repositioning require relatively more muscle activity, and the efficient exchange of energy between kinetic and potential forms is not as well matched, increasing energy use per unit distance. At faster speeds, propulsion and braking demands go up, plus less efficient muscle activation patterns, again raising metabolic cost per meter. Since you’re always spending energy while moving, the cost can’t be negative, so it increases as you deviate from the optimal speed.

The main idea is that energy cost is minimized at a specific walking speed, and moving away from that speed makes the energy cost per distance rise. When you walk faster or slower than the optimum, the body has to do more work per meter to produce movement. At slower speeds, stabilization and limb repositioning require relatively more muscle activity, and the efficient exchange of energy between kinetic and potential forms is not as well matched, increasing energy use per unit distance. At faster speeds, propulsion and braking demands go up, plus less efficient muscle activation patterns, again raising metabolic cost per meter. Since you’re always spending energy while moving, the cost can’t be negative, so it increases as you deviate from the optimal speed.