Exercise during pregnancy.  Everyone seems to have an opinion, but who and what information can you trust? A sampling of advice may include âwalking onlyâ, âno impactâ, âno twistingâ, âstick with yogaâ, âdonât get your heart rate above 140 bmpâ, âand the always popular, âjust do what youâve been doing for exercise.â  Well, what if the woman has been training …