Regardless of your sport or athletic ability, the BOSU Balance Trainer can help make you a better athlete! From strengthening a reconstructed knee to setting world records, BOSU allows you to find your "point of challenge" and develop beyond it!The BOSU Ball is a balance trainer that is challenging and safe for all levels. BOSU is an acronym for Both Sides Up - Both Sides Up because you can use the BOSU Balance Ball with the bubble side up or down. From the elite athlete to weekend warriors trying to stay in shape, BOSU Balance Ball helps to strengthen and coordinate your structure including the muscles of your body that you don't see. The BOSU Balance Ball targets the core muscles of your body - those muscles around your abdominal and back area - helping you to not only gain strength, trim and tone but to help coordinate your entire body. Virtually any exercise you can perform on the ground can be performed on the BOSU Balance Ball - making that exercise More Challenging! More Fun! and More effective!