The paper examines the theory and methodology of conditioning in rugby. It has been established that rugby is a physically demanding sport, requiring players to develop various aspects of conditioning such as strength, speed, flexibility, and aerobic endurance. Adequate conditioning is fundamental to performing all rugby skills, and its significant role in injury prevention has been identified. Furthermore, a correlation between the theory and methodology of conditioning in rugby has been established. Coaches and players should be familiar with the theoretical foundations of conditioning, different types of training, and when and how to implement them. However, there is a wide variety of exercises and training types available for each aspect of conditioning, which need to be adapted to the individual characteristics of the players. This emphasizes the importance of monitoring and testing players. It is necessary to ensure proper execution of exercises and training, as well as to plan their volume and intensity. Considering the timing, conditioning can be divided into off-season preparation, pre season preparation, and in-season preparation. Due to the nature of this sport and its significant physical demands, rugby conditioning training has numerous specifics. Generally, it is not advisable to use general fitness or bodybuilding workouts; instead, they should be adapted to the game's requirements. In conclusion, it has been established that rugby conditioning is highly complex but essential for success in the game and injury prevention.