Enjoy the second trimester of pregnancy, when all the ailments of the previous months are gone, and the small size of your belly still allows you to be active and mobile. Attend sports classes for expectant mothers, go swimming, sign up for childbirth preparation courses. If you've never done strength training before, now is not the best time to do it. If you are an experienced athlete, then pregnancy without complications is not a reason to interrupt your training. The only restrictions are contact sports, during which you can fall or get hit, as well as scuba diving.