Are you pregnant and running any pregnancy complication? If yes, then before adopting any exercise plan do consult your midwife regarding. Bleeding during pregnancy is common and when a woman is going through that complication she must stop doing exercises. Not only bleeding, if there is low placenta, weak cervix, threatened miscarriage and early history miscarriage then exercising during pregnancy needs not to be done. You can consult your midwife or health care practitioner in order to seek a better advice.