Many individuals’ proficiency does not increase with greater accumulation of experience; rather, their capabilities plateau once they achieve a level of acceptability. Improving one’s performance is complex and multi-faceted (e.g., physical, intellectual, skill acquisition, resiliency) endeavor. Research has shown that deliberate practice is effective at increasing one’s level of capabilities. This article, the first in a two-part series, will describe what deliberate practice is, with the second article providing recommendations on how to implement deliberate practice.