You need:
– balloon for each person with spares for accidents
Fun relay race. Have a number of balloons enough for each team member. Put the balloons in a pile at one end of the room and teams in a line at the other end of the room.
The first person runs, picks up a balloon, puts in between their knees and holding there they have to get back to their team and without using their hands just their knees, pass it onto the next member of the team who also has to use just their knees to get the balloon.
This continues down the line to the last player who when they get it have to pop it with their knees and then run to the balloon pile and repeat the process. This continues until the first person who ran is back once again at the front.
Have plenty of spare balloons to replace those that accidentally pop during the game.