¹Anthropology, New York University, ²Anthropology, University of Washington, ³Orthopaedics and Sports Medicine, University of Washington

Saturday All day, Clinch Concourse

Previous research into the effect of gradient or burden transport on energy expenditure has focused on males, with little attention given to understanding the interactions among variables.

To address this deficit, we had eight women walk at three different gradients (0%, +5%, +10%,), with and without a 10kg burden, which was carried in a standard backpack. They walked on the level at their slow, normal, and fast walking velocities, which were chosen while unburdened. For the incline trials, they walked at the same velocity as their slow and normal walking velocities on the level. Their volumetric consumption of oxygen (VO2) was collected using a Sensormedics Vmax 29c metabolic cart and standard anthropometrics were assessed.

Preliminary results indicate that in addition to mass, velocity, and gradient (all p-values ≤0.001), energy expenditure is influenced by the interaction of burden and velocity (p=0.059), with 57% of the variation in VO2 explained (r² = 0.57, all coefficients > 0). Other potential interactions, such as that between body mass of the subject and burden mass, did not reach significance, but this may be due to the current inadequate sample size. While further data collection is needed, these preliminary results indicate that, similar to the limited data for men, velocity and burden interact to increase energy expenditure on inclines.