Optic flow and cycling effort: Where to look to go faster

Optic flow can significantly influence the perception and exertion of effort. In this study, we investigated the effects of exposure to proximal and distal areas of the optic flow field on exerted and perceived cycling effort. Thirty cyclists participated in two 20-min cycling trials within a virtual reality environment, with the goal of surpassing the power output achieved during a baseline trial. During these trials, they viewed the environment through a proximal or distal window, in counterbalanced order. We measured the cyclists' exerted effort on a bicycle trainer, and recorded their responses regarding perceived effort and psychological momentum experience. A one-way repeated measures ANCOVA with average baseline power as a covariate revealed a significant difference in exerted effort between the proximal and distal condition, with higher average exerted effort in the proximal condition. However, a significant interaction effect between condition and baseline power indicated that the beneficial effect of the proximal condition was mainly present for lower-level cyclists. We observed no significant differences in perceived effort or psychological momentum. These findings provide novel insights into the relation between optic flow and cycling effort, and call for new research on the mechanisms underlying this relation.