How to choose a Swiss-Ball

The Swiss ball has been with us for a long while, since 1963 to be exact. It was invented by Aquilino Cosani, an Italian plastics manufacturer. Swiss balls today are almost de-riguer in gyms and it is not unusual to spot one in place of a chair at work or at home. But with so many choices available, buying one can be a daunting. So how does one go about choosing a Swiss ball?

The two most important criteria in picking the right Swiss ball (also known as Gym Balls, Fit Balls and Exercise Balls) are the Size and the ball Material.

Size Matters

First on Size, Swiss balls often come in several standard sizes - 45cm, 55cm, 65cm and 75cm in diameters. The most common method of choosing the right-sized ball to fit a person is the 'Sit on the Ball' test. Sit on a properly inflated Swiss ball with your feet flat on the ground and your knees should end up just below your thigh. If your knees are at a level higher than your thigh, the ball is too small for you.

It is possible to inflate or deflate the ball a little more or less than its recommended size but not too much. Because,

• If over inflated, you run the risk of the ball bursting at the worse possible moment.
• If under inflated, it becomes less wobbly, losing its 'unstable surface' properties that make the ball a great stability exercise tool. An under inflated ball also presses against the back of your thigh when sitting down. This can restrict blood circulation during prolonged sitting.

If you intend to use the ball for other exercises other than sitting, you should test the ball size to see if your posture or form is right performing those particular exercises.

Substance Counts Too

One thing that you will notice almost immediately is that the cheaper Swiss ball tends to be quite stretchy. Avoid these materials if possible as their stretchy properties make it harder to properly size a ball to fit you. Sitting on a 65-cm ball can quickly squish it down to a height of a regular 55cm ball. Stretchy materials also tend not to be anti-burst.

Anti-burst will be a common selling feature when you shop for Swiss balls. But what does it mean? Well, it doesn't mean that your ball will never break or puncture. What it does mean is that when you get a puncture and if you happen to be sitting on it, it will deflate slowly giving you time to get off or if not, fall more gently to the floor.  When a regular Swiss ball is punctured, they pop like balloons - that is very quick, leading to injuries. Anti-burst Swiss ball material tends to be more rigid but not all rigid material is anti-burst. If unsure, ask your therapist or personal fitness trainer for advice. A good Swiss ball should last you for several years.