I’m a hiker—“born to hike,” as my husband likes to joke. It does my heart and soul good to strap on a pack and head out on a trail, especially when I’m alone and can let my mind wander where it will.

At first, walking and hiking may sound like two words for the same form of exercise. The footwear and scenery may vary, but the lower-body mechanics seem the same. Surprisingly, though, they’re ...