The fact that a man can have children at the age of 70 means that he still maintains a certain level of sexual function and can still expel sperm.
Normally, the fertility of both men and women will gradually decline with age, but it is not excluded that a man can still have children at 70 years old. The main reason why men at the age of 70 can still have children is that their sperm quality and sexual function still exist, and they can have sex normally and expel sperm.
Of course, usually, compared to young men, the fertility of men at the age of 70 is significantly reduced, it is recommended that older men ensure that they have enough rest time, avoid overwork, and have a proper sex life. Usually need to actively exercise, enhance physical fitness, improve immunity. If you feel unwell, you should go to the hospital in time.