Yoga balls sit and exercise. Choose a higher or shorter size according to your height. Yoga balls are 45CM, 55CM, 65CM, 75CM, etc. You should choose the size of the yoga ball according to your figure. When pumping up, you should hit "eight points full". When sitting on a yoga ball, your thighs are parallel to the ground and your knees are at 90 degrees. Petite ladies choose 45cm or 55cm yoga balls, while 65cm and 75cm yoga balls are suitable for tall men. People who are overweight and have long arms choose large yoga balls to practice. According to their height, it corresponds to a 75CM ball. If they feel uncomfortable, they should change to an 85cm ball. Yoga ball generally refers to fitness ball. This big ball, which looks like a toy, can be used for fitness. It's called a fitness ball. This rubber fitness ball can withstand up to 400 kilograms of pressure.