Perceptual modification of the built environment to influence behaviour associated with physical activity: Quasi-experimental field studies of a stair banister illusion

Re-engineering the built environment to influence behaviours associated with physical activity potentially provides an opportunity to promote healthier lifestyles at a population level. Here we present evidence from two quasi-experimental field studies in which we tested a novel, yet deceptively simple, intervention designed to alter perception of, and walking behaviour associated with, stairs in an urban area. Objectives. To examine whether stair banister adjustment has an influence on perceptions of stair steepness or on walking behaviour when approaching the stairs. Methods. In Study 1, we asked participants (n=143) to visually estimate the steepness of a set of stairs viewed from the top, when the stair banister was adjusted so that it converged with or diverged from the stairs (±1.91º) or remained neutral (±0º). In Study 2, the walking behaviour of participants (n=36) was filmed as they approached the stairs to descend, unaware that the banister converged, diverged or was neutral. Results. In Study 1, participants estimated the stairs to be steeper if the banister diverged from rather than converged with the stairs. The effect was greater when participants were unaware of the adjustment. In Study 2, walking speed was significantly slower when the banister diverged from rather than converged with the stairs. Conclusions. These findings encourage us to speculate about the potential to economically re-engineer features of the built environment in order to provide opportunities for action (affordances) that invite physical activity behaviour or even promote safer navigation of the environment

Responsiveness of isolated thoracic aorta to norepinephrine and acetylcholine in cold-acclimated rats

We investigated the responses of thoracic aortae to adrenergic contraction and endothelium-dependent relaxation following chronic exposure to cold in rats. Two groups (CA, cold-acclimated for 12 weeks at 5 °C; WA, warm-acclimated for 12 weeks at 24 °C) of 10 male Sprague-Dawley rats were used. After anesthesia, the thoracic aortae (4 mm long) were isolated and the vascular tension was measured with a force transducer. The dose-response relations for aortic responses to norepinephrine (NE), phenylephrine (PE) and acetylcholine (Ach) were determined and compared between the CA and the WA groups. In the CA rats, the thoracic aortae became more sensitive to Ach-induced vasorelaxation. The vascular sensitivities to NE- or PE-induced contraction in the thoracic aortae were lowered. Chronic exposure to cold decreased NE- and PE-induced vasoconstrictive responses and increased Achinduced vasorelaxative response of the isolated thoracic aortae, which were suggested to be due to enhanced release of NE-induced endothelium-derived relaxing factor by up-regulating endothelial α1-adrenoceptors