In an article published recently in the American Journal of Physical Anthropology, researchers from the Paleophysiology and Ecology Group of the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) analyzed the influence of body proportions on the cost of locomotion by means of an experimental energetic study with 46 subjects of both sexes, whose results indicate that the walk of Pleistocene hominins was no less efficient energetically than that of current humans.