Physics says that moving matter across space is the process which takes the most energy. And the most massive an object (or a living being) is, the more energy is needed to move it around. So, walking briskly looks like a good candidate, if not running, which is harder on the joints.
Physics says that moving matter across space is the process which takes the most energy. And the most massive an object (or a living being) is, the more energy is needed to move it around. So, walking briskly looks like a good candidate, if not running, which is harder on the joints.