Exercise balls are soft elastic balls that range in sizes from 35 to 85 centimetres to accommodate people of varying heights. Exercises balls were first used by a British physiotherapist named Mary Quinton to treat infants. Quinton was working in Switzerland at the time. Other physical therapists in Switzerland then began to incorporate the exercise ball in their neuro-developmental treatment.
Because of they first appeared in Switzerland, exercise balls are often called Swiss balls. They may also be referred to as stability balls, fitness balls, Pilates balls, yoga balls and physioballs. The name stability ball is often used by fitness professionals because of the stabilisation benefits provided by exercise balls. When a person exercises sitting or lying on an exercise ball the unstable surface of the ball causes a nervous system reaction leading to an increased recruit of muscle to maintain balance. Working out with an exercise ball improves coordination, core strength and balance.