Invented in 1999 by David Weck, the BOSU is an inflated rubber hemisphere attached to a rigid platform.  The name originally came from an acronym standing for “BOth Sides Up” – a reference to the two ways a BOSU ball can be positioned.  The BOSU is extremely versatile, used for balance training and cardio drills that are much safer for your joints!  The combination of stable/unstable is a great training device for a wide range of users – from the young to the elderly, or injured to elite level athlete.