Expand the description and view the text of the steps for this how-to video.

Check out Howcast for other do-it-yourself videos from carlo_scialla and more videos in the Pregnancy Health & Fitness category.

You can contribute too! Create your own DIY guide at http://www.howcast.com/videos/​new or produce your own Howcast spots with the Howcast Filmmakers Program at http://www.howcast.com/filmmak​ers/apply.

Exercising throughout your pregnancy will make you feel good, keep your weight gain reasonable, and—let's face it—likely be more helpful in the delivery room than picturing yourself on a tropical beach...

To complete this How-To you will need:

Time to dedicate to regular exercise
Plenty of fluids
A good sports bra
Common sense

Warning: If you didn't exercise before your pregnancy, get your obstetrician's okay before you start working out.

Step 1: Carry on

If you're already a fitness buff, continue your routine as long as you feel up to it. However, there are a few activities you should avoid no matter how athletic you are: downhill skiing, contact sports, and scuba diving.

Step 2: Choose wisely

If you're a fitness first-timer, try walking, swimming, yoga, aerobics, and/or light weight training.

Step 3: Start slowly

Start out slow. Walking for a mile at a brisk pace three times a week will lay a strong foundation for more rigorous exercise, later in your pregnancy or afterward.

Step 4: Take five

Take five minutes to warm up before you exercise, and five minutes to cool down after.

Step 5: Stay hydrated

Stay hydrated. Drink plenty of water before, during, and after your workouts. Extra fluids are vital during pregnancy.

Step 6: Dress appropriately

Support your newly voluptuous—and probably sore!—breasts with a good-fitting sports bra. Wear shoes designed for the activity you do.

Step 7: Tone that tummy

Tone that tummy! Strong abs make for an easier delivery, and will bounce back more quickly post-partum.

Tip: After the first trimester, don't do any exercise that requires lying on your back: You'll put pressure on the vein that carries blood to your heart.

Step 8: Strengthen birthing muscles

Strengthen your birthing muscles -- yep, those -- with Kegels. Simply squeeze and release as if you're stopping and starting the flow of urine. Twenty reps five times a day is a good goal.

Tip: Don't overstretch or make sudden moves. During pregnancy your ligaments and joints loosen up considerably, especially towards the end of your term, putting you at risk for injury. Don't overstrain yourself.

Step 9: Consider a mommy-to-be class

Consider taking an exercise class that's tailored for moms-to-be. Then you won't have to think about whether what you're doing is safe or not (as long as the instructor is qualified). And you'll have other women around to motivate you.

Step 10: Don't overdo it

Whatever you do, don't overdo it. Stop any activity if you feel dizzy, short of breath, start having contractions or vaginal bleeding, or if your legs swell up.

Tip: A good way to make sure your aerobic workouts aren't too intense: If you can talk while you're working out, you're fine.

Step 11: Don't feel guilty

Don't feel guilty if you reach a point where you just can't do it anymore—especially toward the end of your pregnancy. Go ahead and relax: That little baby is going to keep you on your toes soon enough.

Thanks for watching How To Exercise When Pregnant! If you enjoyed this video subscribe to the Howcast YouTube channel! http://www.youtube.com/subscri​ption_center?add_user=howcast