Antarctica on foot: the energy expended to walk, ski and man-haul
L. G. Halsey1 • R. Lambert2 • P. Collins1 • A. Newnham1 • A. Kumar3 • C. O’Driscoll1 • M. A. Stroud4
Polar exploration often involves travelling on foot and thus is physically intensive, with long-term excur- sions typically resulting in weight loss. Few studies have investigated the energy expended under such circumstances. Here, we present a range of prediction equations for esti- mating metabolic rate from heart rate or accelerometry data for specific activities including skiing and man-hauling which can be applied to either short- or long-term excursions. We also use some of these equations to estimate the energy expended undertaking various activities by a team of explorers while attempting to traverse the Antarctic conti- nent during the austral winter of 2013 (as part of the White Mars Project during The Coldest Journey). Calibration equations based on either accelerometry data (from which overall dynamic body acceleration, ODBA, is derived) or heart rate showed good relationships with rate of oxygen consumption, particularly when person height was included. Periods of skiing and man-hauling on The Coldest Journey were estimated to be more energetically demanding (30.0 and 31.1 kJ min-1, respectively) than walking (24.9 kJ min-1), or other outdoor work (21.9 kJ min-1).