After giving birth, many women are eager to get back to the gym and start working off their pregnancy weight, but doctors warn - don't rush into it.

Emergency medicine doctor Comilla Sasson says many women often don't think about how much their body changes after they have their babies.

"Some of those changes that you see is there is a hormone called Relaxin, which is actually a hormone that helps to open up the pelvic floor so you can actually give birth to the baby, so it makes it easier to have a baby in that way," said Dr. Sasson. "After you've had the baby, that hormone is still around and what that can do is loosen up a lot of the ligaments and tendons in your body. It can actually lead to injury, and that actually happened to me."

Dr. Sasson tore a ligament in her foot because she wasn't careful with her workouts post pregnancy.

She says its best to start off slowly, with walks and other easier exercises to help build strength before getting into longer, more extensive workouts.

"It might take two to three, to four weeks before you really can start doing that 20 to 30 minutes of exercise and working your way up," Dr. Sasson said.