She writes all about it in her column for the UK supermarket Waitrose.
This has been a hot, hot summer and there's nothing better than a dip in the pool when you're pregnant and overheated, as pregnant Pippa Middleton Matthews notes in her column for UK supermarket Waitrose.
"From personal experience, I'd confidently say I find it has been the most enjoyable and rewarding form of exercise since I found out I was expecting," Middleton writes.
Earlier this summer Middleton used the column to officially announce that she was pregnant by authoring an article titled "Exercising during pregnancy: first trimester." Until that article was published she hadn't yet spoken publicly about her pregnancy, although there had been much speculation in the media.
Middleton broke her silence on this issue by noting that she "was lucky to pass the 12-week scan without suffering from morning sickness," something she no doubt worried about considering her sister's history of Hyperemesis Gravidarum. Feeling happy to skip that, Middleton has been able to keep quite active during her pregnancy, and recommends swimming to fellow expecting mamas.
"As the summer weather contributes to feelings of bloating and swelling, swimming will keep your body cooler while exercising, something that is a relief in pregnancy, preventing swelling in the arms and legs. But even in the cooler months, temporarily joining a local pool can be worth the investment," she writes.
Health officials in Pippa's part of the world agree. The UK's National Health Service also recommends swimming to pregnant women, noting they "might like to try swimming because the water will support [the] increased weight. Some local swimming pools provide aquanatal classes with qualified instructors."
In the United States and Canada, such classes are often called "prenatal aquafit" or "prenatal water aerobics" and are totally doable even if you aren't as athletic as Middleton. They're totally safe, too.
Studies note the "regular practice of moderate water aerobics by low risk and previously sedentary expectant mothers offers no risk to the health of the mother or the child" and swimming in early to mid pregnancy has been linked to a slightly reduced risk of preterm labor.
So if you're pregnant and hot, taking a dip in a cool pool might do you some good. Take Pippa's word for it.