As scientific research delves deeper into exercise physiology, our understanding of physical activity has advanced significantly. Current mainstream exercise modalities primarily include endurance training and resistance training. While each modality emphasizes distinct aspects such as improving muscle mass, cardiopulmonary function, neurocognition, and endocrine metabolism, their effects are not uniform but are significantly modulated by age. Existing research has predominantly focused on younger populations, leaving a gap in the systematic synthesis of how the effects of different exercise modalities evolve with aging. This review aims to summarize the characteristic effects of endurance training and resistance training on the human body. Building on this foundation, it focuses on examining the age-related heterogeneity in the impact of exercise on the skeletal muscle, cardiovascular, nervous, and endocrine/metabolic systems between older and younger populations, while analyzing the underlying mechanisms. This paper highlights that, compared to younger individuals, aging leads to functional decline and metabolic alterations in the aforementioned systems. Consequently, older adults exhibit distinct characteristics in their physiological responses, adaptive capacity, and degree of benefit from exercise. Examples include attenuated post-exercise muscle protein synthesis, more pronounced cardiovascular and neuroprotective effects, and diminished recovery capacity. Therefore, when designing safe and effective exercise regimens for the elderly, it is essential to consider age-specific factors and judiciously select the exercise modality, intensity, and duration. The significance of this review lies in its systematic integration of evidence on the interaction between exercise and aging. It provides a theoretical basis and novel insights for developing individualized and precise exercise intervention strategies for older adults, which holds considerable importance for promoting healthy aging.