Here is a PE idea, which is designed to improve children's ability of Marking other players and increase their awareness of space.
First you’ll need to set some boundaries for this activity. Children will need just enough room so that they can run around freely, but are still close to each other. Then you’ll need to explain the warm up, you’ll need to demonstrate this warm up idea, if not children won’t quite get it. The concept is each child chooses another person to be their dragon, but they don’t tell anyone who their dragon is. Then when you start the activity you have to get as far away from your dragon as possible, while still staying within the boundaries of the area. You’ll find that as everyone has different dragons it prompt a lot of running and dodging to really get as far away from your dragon as possible. When children have had a go for a few minutes and got the concept, I then introduce the shields. Again ask each child to pick someone (a different person to the dragon) and they are now their shield. The idea now is to still keep away from your dragon, but try and get your shield in between you and the dragon to protect you in a straight line.