Strong spatial-awareness and visual perception skills can improve an athlete's performance, enhance training and reduce the potential for injury. This research study looks to investigate the barriers and design requirements for developing an augmented reality headset for downhill winter athletes, which may improve visual perception and spatial-awareness. This research used a variety of human-centred-design methods, including surveys, experience-simulation-testing, user-response-analysis, and statistical analysis. 34 participants with experience skiing, or snowboarding at different skill-levels, wore an augmented reality headset and evaluated the visual perception of an icon, while a slope changing platform system simulated a downhill skiing experience. The results revealed various levels of athletes may benefit differently from access to athletic data during an activity, and indicated some expert level athletes can train to strengthen their spatial-awareness abilities. The results generated icon colours, locations within the field-of-view, and alert methods which could be utilized to optimize the design of headset displays.