The effects of exercise on the endocrine system are complex physiological processes that regulate hormonal balance, metabolic health, and performance. This review examines the influence of acute and long-term exercise on key hormones such as cortisol, testosterone, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and estrogen, emphasizing individual factors like gender, age, training status, puberty, and the menstrual cycle. Aerobic exercise typically induces catabolic responses, while anaerobic and resistance training stimulate anabolic hormones. Regular exercisers display more stable endocrine regulation, whereas sedentary individuals often experience sharp increases in stress hormones. Gender differences are evident—men show stronger testosterone responses, while women benefit from estrogen’s balancing and anti-inflammatory effects. Although hormonal sensitivity declines with age, regular physical activity helps maintain endocrine stability. During puberty, increases in GH and testosterone are pronounced, while menstrual cycle fluctuations affect women’s performance and fatigue. Training models such as cluster-type resistance exercise promote more stable cortisol responses and favorable hormonal adaptations. Overall, understanding the interaction between exercise and the endocrine system is vital for improving performance, managing recovery, preventing overtraining, and developing individualized training and rehabilitation strategies that support both athletic and metabolic health.