Identical twins originate from one particular egg that's been fertilized by one sperm. For unknown reasons, the fertilized egg splits into 2 or more embryos during the first stage of development. Some identical twins share the same placenta. However, they generally grow within separate amniotic sacs inside the uterus. In rare cases, identical twins share one amniotic sac (monoamniotic). Exercise is extremely important for a couple of reasons. You need to train hard in order to boost your testosterone levels. Try to frequent a gym for at least 4-5 days a week. Strength training is excellent for increasing testosterone in your body.