The triceps surae muscle-tendon unit (MTU) is the key for effective force generation, transmission, and energy storage and release in human movement, impacting efficiency, but its injury rate remains high. This paper provided an overview of MTU function and its biomechanical adaptations during running, aiming to deepen the understanding of MTU’s role in movement and to explore how external factors influence its biomechanical properties, offering scientific insights for improving running performance and preventing injuries. During running, forefoot striking and wearing shoes with greater stiffness, such as shoes with carbon plate, the contraction or return energy could be achieved through a more economical MTU behavior, namely reduce energy consumption by more economically muscle contraction and more energy storage of elastic element and the muscle contraction was exerted at a length closer to the optimal muscle fascicle length and reduce energy consumption caused by muscle contraction. However, adopting forefoot striking, barefoot running, or wearing minimalist shoes during running could increase the mechanical loads on the MTU. After gait retraining, the MTU could contract or recoil energy more efficiently while running, while the impact of other training methods on it is relatively poor, and the research in this area is still not sufficient. Therefore, future research should focus on optimizing the biomechanical properties of the MTU, MTU interaction and balanced development through changes in movement patterns, equipment, and training methods to enhance performance and reduce injuries.