Britney Spears has been showing the moment she was "planning" on having babies. The 40-year-old singer is now pregnant with her third child, but she wasn't quite yet as she arched her back in only bikini bottoms from a luxurious beach vacation in March. Soaking up the sun as she showed off her toned body, the "Toxic" singer wrote: "Planning on having babies in Polynesia."
Read on to learn about the activities that help her stay in shape, as well as the photographs that prove they work—and don't forget to check out the 30 Top Celebrity Swimsuit Moments to become beach-ready too!