Giving such permission can be dangerous, especially if your web application uses that same username.
Now the web user (and the whole world wide web) also has the permission to create and drop objects within your database. Think SQL Injection!
I recommend granting Execute privileges only to the specific user on the given object as follows:
grant execute on storedProcedureNameNoquotes to myusernameNoquotes
Now the user myusernameNoquotes can execute procedure storedProcedureNameNoquotes without other unnecessary permissions to your valuable data.