Embodied perception of locomotor challenge in overweight individuals

Abstract

Background Dual-process models of embodied perception contrast explicit perception of stimulus properties with implicit perception that sub-serves action. Explicit perception of stairs is exaggerated, with greater exaggeration when climbing resources are depleted. This perception of steepness promotes avoidance by pedestrians when an alternative is available. Overweight pedestrians avoid stairs more than those who are healthy weight (Eves, 2014). Data from three studies test whether stairs appear steeper in explicit awareness to overweight individuals. Methods For explicit estimates, participants verbally reported stair angle in degrees and performed a visual matching task for the perceived cross-sectional angle of the stairs. In addition, participants adjusted an unseen plate to parallel the slope of the stairs with their hand. In study one, participants self-reported their BMI (n=269) whereas in study two clearly overweight and healthy weight individuals were recruited using BMI silhouettes (n=171). In study three (n=52), BMI was measured objectively and DXA scans used to estimate fat and fat free mass (FFM). Findings In all three studies, increased BMI was associated with greater explicit estimates of stair steepness. Further, this exaggeration was related to the fat mass that would be carried up stairs rather than the FFM that would do the carrying. Changes in fat mass, rather than FFM, were related to changes in perceived steepness. Discussion Increased stair climbing is one public health approach to increase daily energy expenditure in the population. Embodied perception of locomotor challenge may run counter to public health attempts to encourage lifestyle physical activity in the overweight.