The benefits of cross-training in a fitness regime include preventing injury, enhancing overall fitness levels, and improving performance across multiple activities. By incorporating various exercise modalities, like strength training, running, and cycling, individuals can work different muscle groups and reduce the risk of overuse injuries. Cross-training also helps in maintaining motivation by providing variety and challenge in routines. It improves cardiovascular fitness and can enhance specific skills related to other sports or activities, promoting a more well-rounded fitness approach.