Anti-Burst gym balls are highly recommended, as they are the safest exercise ball variants available. If an exercise ball has an Anti-Burst rating, it will deflate slowly when punctured. Other balls may burst suddenly and potentially cause injury. One of our most popular swiss balls is designed using anti-burst material. This is so that exercises can be carried out safely during pregnancy. This design provides peace of mind while doing sit ups and exercising on it. The cushioned surface and shape of the ball help to prevent bad posture or technique.