What is the effect of climbing on a fit walker's average walking speed?

When a fit walker encounters an incline while walking, the demand on the body increases due to the additional effort required to overcome gravity. This results in a decrease in walking speed because the walker must expend more energy to maintain forward motion. The incline challenges cardiovascular endurance and muscular strength, leading to fatigue more quickly, especially if the incline is significant. As a result, to maintain a steady pace, the walker may need to reduce their speed when navigating uphill. The physiological effects of climbing—such as increased heart rate and exertion—contribute to this reduction in average walking speed. In contrast, walking on a flat surface typically allows for a faster and more sustained pace.