Many women believe that exercising while pregnant is too dangerous — and then there are women who take the other extreme. One woman proudly told me about how she had kept up her habit of high-exertion hiking throughout her pregnancy, even doing a ten-mile hike the weekend before she gave birth!

As is usually the case, neither extreme is correct.

Exercise may, in fact, be quite beneficial to both you and your baby during pregnancy. However, discussing your exercise routine with your doctor is especially important when you are pregnant. Some exercises can be quite dangerous, especially nearing the end of your pregnancy. Your doctor can tell you if any factors in your pregnancy preclude exercise, or a particular exercise. Your doctor should also be able to give you an idea of what kinds of exercise are or aren’t a good idea during pregnancy – they may surprise you!

There are some basic things that you should be aware of when it comes to exercising while pregnant, though.

First of all, exercising while pregnant has definitely been shown to have its benefits. Having stronger core muscles can help with labor and with back pains. If you’re having problems with gestational diabetes, or are at risk of gestational diabetes, exercise may help. Plus, those endorphins can really boost your mood!

Second, you will be more prone to injuries while you’re pregnant. Hormones (namely relaxin) which are important for loosening your body up for labor also make you more susceptible to injuries, especially of the joints and ligaments.

Third, there are some exercises you really shouldn’t be doing while pregnant. Of course, mountain biking during your third trimester isn’t a good idea. There are also less-obvious exercises you should probably avoid during pregnancy, as well as exercises that you may be surprised to find are perfectly safe. Again, I refer to what I was saying earlier: speak to your doctor to find out what you should and shouldn’t be doing during your pregnancy. And keep in mind, many of the exercises you can safely do during your first trimester won’t be a good idea during your third trimester.

An always good rule of thumb, though: if you don’t feel right doing it, don’t do it!