Fatigue is an objective law of exercise. Long-distance armed cross-country training for special forces is no exception. However, the current understanding of the mechanisms of exercise-induced fatigue is overly simplistic. The occurrence of exercise-induced fatigue is a process and most interventions to eliminate fatigue are medical in nature and are often implemented at the end of exercise training. This article, based on the understanding that fatigue is an inevitable result of exercise training and is present throughout the training process, summarizes the intrinsic mechanisms of exercise-induced fatigue and applies systematic theory to recognize and objectively analyze the model for systematic control of exercise fatigue. It proposes using step length as an observational indicator to measure the accumulation of exercise fatigue and establishes a systematic control model for exercise fatigue mechanisms. The aim is to dynamically control the degree of fatigue without disrupting the training process, thereby reducing noncombat casualties and helping to improve the ability of special forces to successfully carry out combat missions.