Why are Elves so much lighter than other races

While the fellowship is trying to make for the pass of the Redhorn Gate, during Book 2 Chapter 3, why is it that Legolas seems so much lighter than his companions of other race? Are elves actually physically lighter than others or is it just one of the many graces given to the Eldar by Eru?

With that he sprang forth nimbly, and then Frodo noticed as if for the first time, though he had long known it, that the Elf had no boots, but wore only light shoes, as he always did, and his feet made little imprint in the snow.

As a side note, my brothers and I used to always joke that the reason Legolas was so light on his feet was because elves are hollow-boned, but I seriously doubt that that's the actual reason.