Also known as StuffIt and HugIt
You will need two large T-shirts that someone does not mind re-washing/donating. Two thin nylon ropes, or two simple (waist sized) rubber straps, or even belts will work. Also you will need some water balloons. The more you have, the more fun the game becomes. :-)
Ok, Have two volunteers put on the Large T-shirts and strap the nylon ropes about their waists. Split the youth group up into Two teams. Have water balloons ready in two buckets (or more).
At the sound of the whistle the Teams forming two separate lines, grab two water balloons each and stuff them down the shirts of one of the volunteers. (Hence the need for the nylon ropes) If you use a lot of water balloons then eventually the volunteers (assuming they can still stand) take on a very "weighty" look. Continue having the group stuff water balloons down the volunteers T shirts until the water balloons are gone. (or the person tips over. :-), play on grass if possible! )
Line up the two teams again, and this time, at the whistle they are to run up the their designated volunteer with water balloons and pop two water balloons in the persons shirt and then run back again to the end of the line. (Have the volunteers running in place, to add the effect that they are exercising.) The first team to help their T-Shirt victim (ahem...volunteer) loose all their water weight is the winner. :-)
(a variation of this game has the teams run up to their T-shirt victims (volunteers) and hug them trying to pop the balloons in that manner) If you do this method then the game is called: StuffIt & HugIt, else it is called Water Weight Loss
I have found that ALL age groups from elementary to high-school love this one. :-)
Contribution by John Partridge - thanks John!