Swim, walk and yoga during pregnancy:

As any pregnant woman knows, one of the most challenging aspects of pregnancy is maintaining an exercise routine.

After winning seven Olympic medals and breaking the world record in the 200 metres breaststroke, American Amanda Beard is no different.

She took time off from competitive swimming to focus on her husband and first child, who was born in 2010, but she hopes to be back in training for Rio 2016 after the birth of her second child due in June.

As a pro swimmer conditioned to daily pool and fitness training, Beard says has learned to readjust her workout routine around activities that help keep her in the pool and get her body ready for baby number two, while not over stressing her body during pregnancy. Here are her tips for moderate yet effective workouts:

1.  Stretch in the pool. Amanda says even if you don’t usually prefer swimming as a sport, you can reap the benefits of water fitness by stretching or floating in the water to calm and soothe muscles. "Doing gentle stretches in the shallow end may help relieve back pain."

2.  Learn to appreciate walking. "As your belly grows, it becomes more and more challenging to get a good cardio workout without feeling uncomfortable. Consider swapping running with walking. Finding time to walk can be as simple as taking your dog out for a stroll, catching up on the news via headphones while walking the block, finding a place that is visually stimulating in order to keep it fun or walking in the pool to add low-level resistance to your body while further reducing stress on your joints."

3.  Yoga at home. With a 3 year old son and a new baby on the way, Amanda says that a trip to the gym is not always plausible for her. She rolls out a yoga mat at home. "Practice along with a prenatal yoga DVD will allow you to move at your own pace."

"As a second-time mum, I know it can be difficult to find the right workouts in order to feel good and remain physically active while pregnant," says Beard.

"Mixing a variety of simple, low-impact workout solutions, such as swimming, walking and yoga throughout the week, will allow you to feel great and strong throughout your pregnancy."

As well as being a mum, Beard is a blogger and New York Times best-selling author after the release of her first memoir, In the Water They Can't See You Cry.