Aerobic exercise and resistance exercise have their own focuses in improving muscle mass，cardiopulmonary function，neurocognition，and endocrine metabolism，etc. However，their effects are not uniform，but are significantly modulated by age. Based on a review of the characteristics of the effects of aerobic exercise and resistance exercise on the body，this paper focuses on exploring the age heterogeneity of the effects of exercise on the skeletal muscle system，cardiovascular system，nervous system and endocrine metabolism system in the elderly and young groups，systematically integrating the evidence of the interaction between exercise and age，and analyzing its potential mechanisms. Compared to younger individuals，aging leads to functional decline and metabolic alterations in the above mentioned 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.