Advice for the cross swimming:

Body protection: The necessity and quantity of fat covering your body should be decided one hour before the swimming starts. If the water is warm, (24-25 C) only a little fat should be used. If the water is cold (less than 22 C), more attention has to be paid to the fatting.

Meal: 3 hours before the start the swimmers can have a usual and abundant meal, but it shouldn't be too fatty and spicy.

Style: During swimming it's not recommended to change your swimming style.