I have read in a grammar book that there is a difference between these two sentences and it is as follows:
"I have been swimming today" is said shortly after the swimming has stopped, hair is still wet or someone is just leaving the pool, for example.
"I have swum today" is said when the swimming happened earlier in the day. Maybe a few hours earlier.
Is this true? Because I thought that adding "today" makes a difference. I know that "I have been swimming" ( without "today")is said shortly after the swimming has stopped and there are results in the present = wet hair, for example.
Can anyone enlighten me?