Historically, pregnancy has been considered a time when women would simply take it easy, avoid any exertion on their bodies, eat whatever made them comfortable or happy, and move along without caring much about a physical fitness routine and adequate nutrition intake. (Ahem.. you've probably noticed this when watching Betty Draper in episodes of Mad Men.)

But in recent years, doctors have taken on a more cautious approach to pregnancy weight gain. For many women, losing the pregnancy weight is quite difficult, and many of them continue with subsequent pregnancies with their starting weight higher than with their first. Over the last decade, research has demonstrated that both mothers and newborns weigh significantly more than they did in the past, which is contributing to a continuing rise in obesity.

Pregnancy weight gain has become a hot topic in many birth circles, and the Journal of the American Medical Association recently issued new recommendations for mamas-to-be: exercise, exercise, exercise, even if you've never done so before pregnancy.

So now, practitioners and researchers are revising their recommendations, saying that pregnancy is "an excellent time to introduce healthy lifestyle habits because the mother is highly motivated." That's right, you don't need to be an crossfit junky or even an "once-in-a-blue-moon" jogger to work out during your pregnancy.

Since there's a positive correlation between prenatal health and fetal health, physicians now recommend that even those who never worked out before engage in 20-30 minutes of moderate prenatal exercises. How do you know if you're doing too much, too intensely? You should be able to have a conversation while exercising.

A consistent exercise regimen during pregnancy has many benefits: less fetal macrosomia (baby birthweight that's significantly larger than the average, usually over 8lb 13oz); less gestational diabetes and preeclampsia; fewer C-section deliveries; less low-back or pelvic pain; and lower frequency of urinary incontinence. What's more, exercising during pregnancy means your taking care of yourself, which means you're taking care of your child too! In the long run, giving birth to a svelter baby can prevent long-term health issues obesity and diabetes.

A lot of pregnant women find it difficult to fit daily exercise in their schedules. And if you're not a daily exerciser to begin with, it could certainly be a challenge to start making it a habit. But since the benefits of being active during pregnancy outweigh the risks, it's important to try and keep your body moving.

So here are 5 ways to add prenatal activities to your daily schedule (ideally, four to five times a week).

1. Walk instead of using public transportation. You can get off the subway of the bus a station early so as to force yourself to walk a little more every day.

2. Take the stairs instead of the elevator (unless your apartment or your office is on the 33rd floor!).

3. Subscribe to a virtual workout program such as Booya Fitness. Most of their workouts are under 30-35 minutes with a variety of offerings -- a great way to motivate yourself and keep you entertained without using up too much of your time. Plus, you can do it in the comfort of your own home.

4. Check out the Fit4Mom programs in your area as they incorporate baby, stroller and mom workouts. Yes, you can use childcare to give yourself a little physical challenge.

5. Walk around the apartment at various intervals especially after eating a meal. This could also help with digestion.