Pyjama-clad men and women whisk each other off and on to spongy floor-mats all through the winter months. There are grunts and groans, shrieks and guffaws. Dust and sweat mingle in a frenzy of effort. It's a jungle in there sometimes. The idea of being strong, alert and fearless is obviously popular, as self-defence classes continue to attract steady numbers each year around the country.

"It's so important," says Jackie O'Shea, a Karate instructor at Dublin's Litton Lane Studios. "Everybody should do it. I think it should be compulsory in schools. Martial arts is compulsory in schools in Japan for children from the age of four."

George Reilly, her colleague, who also gives Shotokan Karate classes in the Dublin area, is of the same view: "I've never really had to use it but it does give you a lot of confidence. It helps you to read situations. I would be more alert. It's about how you handle yourself."

Greg Manning, general secretary of the Irish Karate Union, says "it's the mental training that is important". He doesn't believe in quick fix classes. Self-defence techniques "take years to perfect. It gives people the mental confidence to defuse situations where necessary." Over the past 10 years, young people, teenage girls in particular, have got involved in Karate, for self discipline, he says.

O'Shea believes that women especially should learn self-defence techniques. "We are inclined to put ourselves down too much". With Karate training or any similar empowering discipline, she believes that women "get an awful lot of respect as well". She is busy every night of the week in and around Dublin at a variety of community and sports centres, training people in Karate.

James Mansfield, who gives a Karate class at Cork's College of Commerce, introduces a self-defence element into his classes "now and again". Self-defence forms a part of Karate, he says, explaining that there are hundreds of Karate techniques which are highly effective in self-defence. He points out, however, that Karate does not only consist of learning these techniques.

The people in his class "are interested" in self-defence segments because "in today's society they need it." Most of those who attend his classes are women, although "there is a handful of men". He trains his students in Shotokan Karate. Classes are between 3.30 p.m. and 5 p.m. two days each week. Most of the students are in the 18 to 23 age group.

"They learn how to use their bodies to defend themselves," says Mansfield. "You learn how to block with your hand and body, how to make a proper fist, how to punch."

He has found that his students are not inclined to be forceful sometimes - they are shy about facing each other and attacking. "They're too nice to each other. They have to think of real life. I try to focus them by reminding them of how they would handle it in real life.

Mansfield has been instructing for a number of years and has also taught foreign exchange students during the summer. Again he has introduced self-defence techniques. "They enjoy it, but none of them takes it too seriously. It's a mixed class generally."

Irish students "are definitely more aware that every day on the street they need it. They feel that little bit more prepared. A lot of people freeze when someone attacks them. They panic. If they're used to being punched they are better able to deal with it. They are more prepared."

Through long practice, he says, students learn to develop a kind of sixth sense in bodily movement. This enables them to react instantly to an opponent's moves and turn them to one's own advantage. He believes that when one has developed even a small amount of this awareness, Karate moves are even more effective as a means of self-defence.

For information about Shotokan Karate classes in the Dublin area, contact George Reilly at (01) 847 1493. Greg Manning, general secretary of the Irish Karate Union, can be contacted at 021-508022 or fax 021-276292.