Walking on soft surfaces causes people to take longer strides, actions that consume more energy than walking on a solid surface.
Walking on the beach on an afternoon when the sky is beginning to turn red is one of the most pleasant sensations there is. Visualize yourself, for example, walking along the dunes of Maspalomas in Gran Canaria and trying to get closer to the sea shining in the distance. And we say trying because there is something a bit complicated about the whole thing: walking on the sand. Why is it so extremely difficult to walk on it?
You don't have to be a lynx to realize that the problem with sand is that it's soft and you sink with every step. As reported by ‘Live Science', that forces you to use 2.1 to 2.7 times more energy with every step you take. But that's not all: the sand deforms when you step on it, the unevenness of the beaches and dunes also makes them difficult to cross.
The sand deforms when you step on it, the unevenness of the beaches and dunes also makes them difficult to cross.
On sand, the base of support is also uneven, and moving on uneven ground requires additional energy, forcing the body to make small, often subconscious adjustments to its gait, involving muscles, especially in the ankle and foot, that might otherwise rest more. These muscles should actively contract to ensure stabilization. A similar effect is also at play when you walk on a trail with lots of rocks and roots; even if you walk at a reasonable pace, you will tire faster than when walking on the sidewalk.
Another idea is that people walk differently on sand than on hard surfaces. One study made a comparison of how they walked on foam versus solid surfaces by analyzing the forces under their feet and the amount of oxygen they consumed. They found that walking on soft surfaces, such as sand, mud and snow, caused people to take longer strides and make larger hip and knee movements, actions that consume more energy than walking on a solid surface.
Walking on soft surfaces consumes more energy than walking on a solid surface.
Interestingly, scientists have found that running on sand reduces the disparity in energy expenditure. Running along the beach requires only 1.6 times more energy than running on a flat, stable surface. However, because running (at least at a fast pace) requires more energy than leisurely walking, you would still expend much more energy running on sand compared to walking on sand.
But as experienced beach walkers know, there is one way to make walking on sand easier: if there is a little water. When sand is wet it becomes more compact and walking on it is more like walking on solid ground. But too much water could again cause the sand to become thick and soft.
The impact is less on sand than on firm ground, and walking or running on it is much easier on the joints and muscles.
Although difficult, there are good reasons to exercise in sand. The impact is lower in sand than on firm ground, and walking or running around is much easier on joints and muscles. This means that sand is a better surface to help athletes recover more quickly from workouts and for people rehabilitating after injuries. Mind you, it is advisable to use caution during sand workouts due to the instability, as you are more likely to fall.
So next time you're taking a nice walk on the beach, remember that you're also working hard, and that way your beer will taste better at the beach bar afterwards.