Ron and I were both overweight (me 15 stones and he 13 stones) when we decided that we must lose weight.  I lost 4 stones (some has gone back on) and he lost just over two.  As part of this effort we joined Criscket St Thomas and swam three times a week.  I could only manage 30 lengths but Ron swam 40 lengths right up to October 2017.  He started struggling and in January 2018 we found out why.  He had a stomach ulcer which the more he swam the more it bled.  Had we known and it had been treated who knows, he might still be alive and regularly swiming today.