last chance workout advice please!

caribeals

HI! i am in a biggest loser contest with about 20 of my family and friends. this is out 3rd competition. this go-around, we weigh in in the late afternoon, around 4:30. before we always weighed in around 8am. my question is this: if i wanted a "last chance workout" before weigh in, should i do it the morning of the weigh in, or the night before? i have heard muscles retain water after a hard workout, but didn't know for how long. what would your advice be? do the final hard workout the morning of, or night before? thanks for you help!!