The term "cross-training" refers to a fitness approach that incorporates various types of exercise to enhance overall performance. Instead of solely focusing on one discipline, such as running or cycling, cross-training combines activities like strength training, swimming, or yoga. This method helps in improving endurance, strength, and flexibility, while also preventing overuse injuries by working different muscle groups. Additionally, cross-training can alleviate workout monotony and lead to improved skill transfer, making it easier for individuals to excel in their primary sport or fitness activity.