A BOSU ball consists of a domed rubber hemisphere attached to a flat platform. It can be used dome-up for balance and core work or dome-down for instability pressing and squatting. The unstable surface forces constant micro-adjustments from the stabilizing muscles, making even simple exercises more challenging. It is a versatile tool for functional training and rehabilitation. Common exercises include squats, push-ups, planks, and lunges. The BOSU ball improves balance, coordination, and core strength. It is suitable for beginners who need a challenge and for advanced athletes seeking to enhance proprioception.