Perception of self-selected running speed is influenced by the treadmill but not footwear.

In this study, we examined whether self-selected overground running speed was consistent (1) with perceived overground speed on the treadmill and (2) among barefoot and three footwear conditions. Participants ran across a 20-m runway 10 times for each overground condition, with running speed calculated from kinematic data. For the treadmill condition, the participants were instructed to run at a speed that felt similar to their overground speed. This treadmill speed was chosen upon perception, with the display covered from the participant's view. Repeated-measures analysis of variance was used to detect differences in speed between overground and treadmill running, and also among barefoot and footwear conditions. Coefficient alpha (alpha) was calculated to determine repeatability of observations in each overground condition. The speed was higher during overground (3.65 +/- 0.40 m/s) than treadmill (2.25 +/- 0.75 m/s) running but did not differ among the barefoot and the three footwear conditions. Overall, overground speed was highly repeatable within an individual (alpha = 0.96-0.98). Researchers might consider using self-selected speed when investigating overground running mechanics with different foot-ground interface conditions. The influence of treadmill on the perception of speed may be related to shear force, running duration, joint load control, and/or other psychological factors.