Fig. 2: Uphill outdoor walking task and metabolic results for young adults.

a, The task involved walking along a steep 500 m uphill trail presenting altitudes of 127 m and 184 m at the start and end points, respectively. Young adults walked at their preferred pace unassisted (grey) or while using WalkON (navy). Credit: Geobasis-DE/BKG (2009) (left panel). b,c, Metabolic results demonstrated a significant reduction in the cost of transport when using WalkON to perform the walking task. This is visible from the cost of transport time-series in b (in which the thick lines represent the average across subjects, and the shaded areas represent the s.d.) and the mean (± s.e.m.) cost of transport values in c. d, The preferred mean walking speed of participants along the trail was not significantly altered when using WalkON. The results are presented as box plots, where bounds of boxes represent the lower (25th percentile) and upper (75th percentile) quartiles, the horizontal lines are medians, and the orange circles represent means. Individual participants results are shown as dot plots. ***P < 0.001 (linear mixed-effects model).