Developed from forms of fitness used by the Ancient Greeks, the sport of gymnastics combines flexibility, strength, balance and endurance through performed sequences of skills and movements such as tumbles, flips, somersaults and twists. Gymnastics refers to one of two main types of gymnastics: rhythmic gymnastics which combines graceful dance-like movements and display or artistic gymnastics which consists of different events using specialist apparatus such as a spring floor, bars, horse, vault or rings. In recent years trampolining and aerobic gymnastics have also emerged as separate gymnastic disciplines.