The popularity of running has been growing in the various parts of the world in recent years. One of the reasons for the growing popularity is that individuals are intrinsically motivated to perform activities that enhance their sense of accomplishment. As a consequence, running training devices also become more popular as runners become more concerned with their run data. Nevertheless, most of these devices do not enhance the runner's competitive experience, which can perhaps aid the runners in achieving their running goals. Using Norman Triplett's concept of social facilitation, competition can be introduced to increase a runner's performance to achieve their goals. Hence, this research introduces the concept of a runner running against his virtual self of a previous performance (also known as the Phantom). By providing this competitive mental imagery, the athlete's intrinsic motivation to improve his performance can be enhanced.
Therefore, this research aims to design the means of providing this competitive mental imagery to the athlete. 3 designs using different feedback are prototyped and evaluated in terms of the runner's sense of a competitive mental imagery when worn. One of them, the Necklace Audio System, is a necklace-like actuator that produces ambient and spatial footsteps sound, which is representative of the Phantom's footsteps, around the runner. This was the best performing prototype and was used for subsequent experiments to evaluate the effects of the Phantom on the time performance of runners. The results concluded that the Necklace Audio System shows positive effects in affecting the time performance of runners, especially when the Phantom is in front or behind the runner. Nevertheless, there are limitations to the system, in terms of the distance sensing unit, awareness inaccuracy for the front Phantom stimuli and the footsteps sound effects, which will be improved in the near future. Future applications also include the extension of the Phantom Runner System to other racing sports and even as a form of game play.