Used in rehab medicine for over 30 years, exercise balls are being integrated into home gyms, yoga studios, even the office! These balls promote fitness in a comfortable, low-impact manner perfect for all ages and levels of skill and ability. Add one to your home gym to stretch out a sore lower back. Add one to your yoga and Pilates routines for deeper, more intense flex. Add one to your office desk to establish a healthier posture and develop your core and legs just by sitting! More advanced users can add them to existing workouts. Suddenly, push-ups and sit-ups become much more difficult--and rewarding!