The principle of specificity in training refers to the idea that training adaptations are specific to the type of exercise performed. This means that to improve a particular aspect of fitness—such as strength, endurance, or flexibility—training must be tailored to target that specific area. For instance, if an athlete aims to enhance running performance, their training should include various running workouts rather than weight training focused solely on general strength. By adhering to this principle, individuals can achieve more effective and efficient results aligned with their specific fitness goals.