CanDo inflatable Exercise Ball Exercise balls are used to improve balance, coordination, flexibility, strength and even just for fun. Balls are used as aids for vestibular movement and equilibrium therapy, by fitness professionals as an aid for stretching and strength programs, as seats, and even by pregnant women in birthing classes. The CanDo balls have a non-slip PVC vinyl surface that is ribbed for extra security. The balls may be "under" inflated to give a soft, mushy feel or fully inflated for a firm, bouncy feel. Standard CanDo inflatable balls can support up to 300 pounds (136 kg) and are available in a polybag or retail box. Available in various sizes.