Running the day after sex does not affect conception. The first condition for pregnancy is the combination of sperm and mature egg to form a fertilized egg. Generally, male semen contains a large number of sperm, and the more vigorous sperm will generally enter the vagina and swim quickly to the female fallopian tubes, where they will combine with the discharged egg to form a fertilized egg and implant in the bed for the purpose of pregnancy. The movement of sperm will not change because of running or jumping rope and other exercises, even if there is a small amount of semen out of the vagina after sex, it does not affect the chances of conception. So running the day after sex will not have any effect on normal fertilization, as long as it is ovulation without contraception will have a chance of pregnancy. However, it is generally recommended not to exercise for a short period of time after intercourse to prevent more semen from flowing out of the body, and can wait until 2 hours after intercourse before exercising, which will not affect the conception.