EXERCISE AND BODY TREATMENTS
If any time is a good time to do regular exercise, then it seems pregnancy is an even better time. But it's good to be aware of changes in your body. If you do intense aerobic activities, you may want to ask your doctor or caregiver if it's appropriate and how long you can do it. It may help to hold the thought that you do your activities with and not despite the baby, and to let a feeling of gentleness and joy guide you in your actions.
While doing exercise, try to be aware of what may feel different and not push yourself too hard. Gentle exercise such as walking, yoga, or swimming, are ideal, especially later in the pregnancy. You may find that in the third trimester you start feeling practice contractions (Braxton Hicks) when you exercise. Doing pelvic floor (Kegel) exercises during pregnancy can be helpful in toning the pelvic floor to aid in the birth and recovery after the delivery, as well as helping with urinary incontinence. If you're going for massage, physiotherapy, chiropractic, osteopath, acupuncture or any other body or energy treatment, it's good to let the practitioner know that you're pregnant.
Dance of the Cranes by Haruyo Morita
In someone used to a particular level of exercise, the body is well able to cope at that level during pregnancy. General activity as well as prenatal exercises to strengthen the muscles of the pelvis and prepare for the birth are important.
Peter W. Nathanielsz 
 Davies, Gregory A. L., MD, FRCSC, et al.. Exercise in Pregnancy and the Postpartum Period. JOINT SOGC/CSEP CLINICAL PRACTICE GUIDELINE No. 129, June 2003, researched August 2009 <http://www.sogc.org/guidelines/public/129E-JCPG-June2003.pdf>
 Nathanielsz, Peter W., M.D., Ph.D. Life Before Birth and A Time to be Born. Promethean Press, Ithica, New York, 1992 page 161