Back in 1986, scientists at University of Nairobi and Harvard studied the remarkable load-carrying capacities of women from the Luo and Kikuyu tribes in East Africa. The women, it turned out, could balance up to 20 percent of their bodyweight on their heads and carry it without using any more energy than if they were walking without any load. It’s a remarkable physics trick—and also a reminder amidst the rucking workout craze that backpacks aren’t the only way, or necessarily the best way, to carry loads.
That’s the observation at the heart of a new study in Medicine & Science in Sports & Exercise from David Looney and his colleagues at the US Army Research Institute of Environmental Medicine and several other institutions. In this case, the focus of their investigation is the energy required to haul a load in a weighted vest. For military personnel and first responders, tactical vests are often an essential part of their gear; for civilians looking to get fit by rucking—that is, by walking around with a heavy load—weighted vests are a popular alternative to loading up a backpack with bricks. But how do…
