The elevated metabolic cost of walking at preferred speeds of healthy elderly on treadmills compared to overground is not related to increased self-reported anxiety

Figures

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  Fig. 1. Schematic overview of the energy expenditure measurements during the experimental protocol. Resting Metabolic Rate (RMR) was measured, while the participants were seated for 5 min on a chair preceding each of the overground and the treadmill walking trials. During the overground trial, participants walked continuously along the schematically drawn oval track with 32 m straights interconnected by two half-circles of 4 m radius. During the treadmill trials, the participants first walked on the high treadmill (placed at a height of 60 cm from the ground) and then on a normal floor-level treadmill at their imposed overground preferred walking speeds

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  Fig. 2. Overview of gross metabolic power (Pmet) results. Means and SEM (standard error of mean, grey area) of gross metabolic power over time (in minutes) have been plotted for the overground and the two treadmill trials. OG represents overground, HTM high treadmill and LTM low treadmill

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  Fig. 3. Boxplots of Gross Cost of Walking (GCoW), Net Cost of Walking (NCoW), self-reported anxiety, and Heart Rates (HR) are shown for overground (OG), high treadmill (HTM), and low treadmill (LTM) walking conditions. The central white horizontal lines in the boxplots represent the median and the black edges of the boxes represent the 25th and the 75th percentiles. The black whiskers of the boxplots extend up to the values that are not considered as outliers and the outliers are depicted by the black ‘+’ symbols. The ‘*’ symbols signify statistically significant elevation (p < 0.05) compared to overground values. For the self-reported anxiety plot, the ‘#’ symbol signify statistically significant elevation (p < 0.05) compared to overground and LTM values