What type of practice would likely lead to boredom in training?

Mass practice involves engaging in repetitive training sessions without sufficient breaks or variations in activity. This can lead to boredom because the same movements or skills are practiced over and over, making the training feel monotonous. Without introducing new elements or changes in the routine, participants may lose interest over time, which can hinder motivation and learning performance.

In contrast, varied practice or randomized practice introduces different skills or activities within a session, keeping the training fresh and engaging. Fixed practice, while it may involve repetition, often aims to perfect a specific skill within a controlled environment, which can sometimes mitigate boredom if the skill is challenging. Therefore, mass practice stands out as the method that is most likely to lead to feelings of boredom in training due to its repetitive nature.