How smimming kills you

Swimming kills you over time because it is like a two and a half hour work out. and if u have ever worked out for one hour obviously a two and a half hour swim would be a little bit more of a work out. I don't really like being sore 5 days of the week 20 days of the month. But i like swimming so i do swim 5 days a week 20 days a month. But i suggest u take up swimming its a fun and good and healthy sport!!!