One of the most memorable images from the recent Beijing Olympics was the sight of thousands of Chinese practicing Tai Chi in the city's parks before going to work. This, combined with the use of the martial art in the event's mesmerizing opening ceremony, has left many people wondering what Tai Chi is and whether it has anything to offer them. Marie Madden reports.

Practised by over 30 million Chinese and over five million westerners, Tai Chi is a form of exercise that can have significant physical and mental health benefits.

The art of moving the body can be both beautiful and calming to watch, as every posture is full of energy, balance and concentrated internal strength.

However, there is also a very interesting philosophy that underpins every posture and change of movement, invoking the concept of Yin and Yang (opposing forces that balance and transform one another).

For example, if one exerts too much tension in one local muscle group, one loses the ability to involve a chain of many more muscles to add strength to the movement and the excessive tension slows down the release of power when Tai-Chi movements are sped up when used for self-defence.

Similarly, if one practises too loosely and in a disconnected way, the blood and chi will not reach the extremities of the body and the force of the whole body cannot be concentrated to a single point as one needs to in order to realise the self-defence applications of the art.

Tai Chi, or Taijiquan, was created 400 years ago by Chen Wangting. Wangting incorporated the study of vital points and energy flowing through the body's acupuncture channel, the Taoist method of using the mind to direct the internal force and breathing techniques, into the physical martial techniques he formulated from 16 schools of boxing.

With today's busy lifestyle, more and more people are turning to this martial art as a way of relieving stress. The meditative nature of moving slowly, co-ordinating your breath and awareness of micro-adjusting your posture to achieve the optimum efficiency and harmony of movement, has the effect of changing the sympathetic dominance (stressed) of the nervous system and stimulating the parasympathetic system (returning the body to rest).

There are a whole range of benefits to practising Tai Chi. For example, blood pressure and heart rate decrease while digestion, blood circulation and removal of toxins improves. Calming the mind also helps to relieve depression and anxiety, elevating one's mood and creating a more positive outlook on life. Memory, attention, concentration and learning improve, as well as confidence. In addition, Tai Chi helps co-ordination and balance and this can positively affect many areas of life.

Many health insurance providers recommend Tai Chi to those who suffer from arthritic conditions and osteoporosis, as it is thought to reduce the amount of falls among the elderly and serves as an excellent low-impact exercise to keep fit and alert.

Those recovering from other sports injuries or illness may also find Tai Chi an excellent way to restart training. Mobility in all the joints increases with the improved flexibility gained from practise. Actors, dancers and performing arts people often use some Tai Chi exercises to increase their sensitivity, force-control and fluidity of movement.