The Science Behind Walking on Sand.
Walking on sand is harder than on solid ground because it requires more energy due to the softness and unevenness of the surface. The body makes small adjustments to gait, engaging muscles in the ankle and foot that might otherwise get more rest. Running on sand reduces the disparity in energy expenditure, but it is still more energy-intensive than walking on a solid surface. Wet sand is easier to walk on than dry sand, and increasing surface area by wearing shoes or changing gait can also help. Sand is a better surface for helping athletes recover more quickly from workouts and for people who are rehabbing after injuries.