Swimming is the most popular exercise for adults, ahead of soccer, golf and Gaelic sports, according to a new report.
Almost 7 per cent of adults - 230,000 people - swim regularly, with the border and midland regions showing the highest numbers of swimmers, the report by the Economic and Social Research Institute of Ireland, Swim Ireland and the Irish Sports Council shows.
The report says there is a need for more pools in the commuter-belt counties around Dublin.
Women are more likely to swim than men: for every three to four men who swim there are four to five women who swim. Women had a big influence on whether their children swam: adults whose mothers were the only parent active in sport and exercise were three times more likely to swim.
"Mothers are our key to getting people into swimming," Dr Pete Lunn of the ESRI said.
More people are swimming as children and tend to keep swimming into adulthood. Just 8.2 per cent of 45 to 59-year-olds swam when they were children as they mostly played Gaelic games and soccer. This grew to 14.1 per cent of 30 to 44-year-olds when they were children and 15.5 per cent for 18 to 29-year-olds.
"If you want your kids to be active in later life and live longer then teach them to swim," said Dr Lunn.
The tendency to swim is also based on education and occupation: almost 10 per cent of people with third level education swim, compared with almost 3 per cent for those with primary school education and 6 per cent for those with second level education.
The report drew on two surveys based interviews with almost 70,000 adults.
Sarah Keane, chief executive of Swim Ireland, said swimming was important for a healthy lifestyle and it should be made more accessible.
Minister for Sport Michael Ring money should not be a barrier to people going to pools and wanted to see pools doing better deals for families wanting to attend. He said he would continue to provide grants to pools to help reduce their heating bills.