Polar exploration often involves travelling on foot and thus is physically intensive, with long-term excursions typically resulting in weight loss. Few studies have investigated the energy expended under such circumstances. Here, we present a range of prediction equations for estimating 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 continent 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). Estimates of energy expenditure during The Coldest Journey were similar to measures obtained in previous, comparative scenarios. We hope that future expeditions to Antarctica will use these prediction equations to further our understanding of the energy costs of exploring Antarctica and the nutritional requirements needed to guard against emaciation
