In its competitive form, CrossFit® intends on assessing the performance of athletes in a wide variety of aspects that determine their conditioning. CrossFit Games is an official competition and intends to recognize the best conditioned athlete in the world to each class. Thus, measuring an athlete’s Physical Conditioning is, in a sense, assigning a set of performance outputs that can determine the efficiency and efficacy of the athlete, discriminating the performance of one or more athletes. Since the scores obtained by the athletes in the various workouts are directly identifiable, the conditioning can be seen through the performance in a competition, it is, therefore, a result of the interpretation and scope of the workouts in measuring the performance. This work analyzed data form “CrossFit Open” and has as an objective to propose a new theoretical arrangement to the sport discipline while being of the Item Response Theory which is capable of providing data such as, discriminatory capacity and difficulty level of the workouts, as well as, an assessment of the competition. In other words, intends to describe the probability of an athlete performing a workout and obtaining a score, given his/her physical conditioning. Analysis of the main indications that refer to a good quality of the measurement tool indicates it is a high quality competition. Lastly, this work accomplished both objectives proposed, methodological as well as practical, and recognizes the limitations derived from the reduced amount of qualitative data on the topic and the little use of applied probability models.