QuestionDear Helene,
I am almost 16 weeks pregnant and even though I am in my second trimester, I haven't felt the need to change my workouts yet in terms of capability. I do spinning followed by weights twice a week and an intense hi-impact cardio session once a week. Also, I am still doing 10 minutes of abs on my back every morning, even though I've read that you should stop once you are in your second trimester. Are these recommendations flexible or is there really a sharp cut-off date at "second trimester?" I'm also still sleeping on my stomach.
The only thing I've changed is that I give myself a little more slack if I start to feel overly exhausted during the workout. I still try to push my limits to some degree, but less so than before I was pregnant.
I'd really appreciate your expert advice.
Thanks,
Nili
AnswerMost athletic women don't feel a need to lower the intensity of their workouts until about 24 weeks or so.
The placenta stops growing at 20 weeks. From this point on, its capacity to transfer oxygen and nutrients is capped. Athletic women, especially those who do a lot of aerobic exercise, grow bigger placentas than less fit women. Athletic women give birth to leaner, stronger, and even smarter babies, so big congrats to you for being a fit momma!
In the last half of pregnancy, your baby grows rapidly and therefore needs more oxygen. So you body does more work to meet this demand, 24/7. This means that your rate of perceived exertion for any given workload will increase and you will need to slowly taper down the intensity of your workouts. Always stay in a zone that you perceive as "somewhat difficult."
Many spinning workouts actually take the body past the aerobic threshold. Take care that you do not do this. You should always be able to exercise and speak in a normal voice during pregnancy, even if you are used to pushing your body harder.
As to the restriction about exercise on the back, you are referring to a condition called Supine Hypotensive Disorder. In less than 10% of all pregnancies, lying on the back will cause compression of the Vena Cava, the largest vein in the torso. If blood flow back to the heart and lungs is restricted enough, then the women will experience sudden dizziness.
There's a lot of misconception about this. Almost everything you read about this topic on the web and in magazines is inaccurate. Lying/exercising on the back does NOT restrict arterial blood flow to the placenta, and does NOT harm the fetus in any way. Several good studies in the last few years show that exercising on the back is in fact safe for most pregnant women. Dr. James Clapp, the leading scientific researcher in the field of prenatal exercise physiology, stated in a conference on prenatal exercise that he believes that this restriction will be revised soon.
But I am concerned about your ab routine. Crunches and other exercises that flex the upper spine are not ideal during pregnancy and may even be a cause of diastasis recti. Because of the postural changes of pregnancy, women should focus their abdominal work on exercises that flex the lower spine, and exercises that require stabilization of the neutral spine. Additionally, all pregnant women should focus on strengthening the deepest abdominal muscle the Transverse Abdominis, or TvA.
TvA strength during pregnancy helps to prevent back pain, pelvic instability, and diastasis recti. Because the TvA is responsible for expulsion, it plays a major role in the pushing phase of labor. After delivery, it's the first muscle you want to rehab, both to repair diastasis and to re-flatten the abdomen.
More information about aerobic exercise during pregnancy can be found at:
http://befitmom.com/aerobic_exercise.html
More information about Supine Hypotensive Disorder during pregnancy can be found at:
http://befitmom.com/supine.html
More information about abdominal and core conditioning during pregnancy can be found at:
http://befitmom.com/strength_training.html
More information about diastasis recti during and after pregnancy can be found at:
http://befitmom.com/abdominal_separation.html
