What Are Some Great Physical Exercises For Teaching Fitness To A Young Soccer Team?

Obviously there are lots of things that you can do, but the main thing in football is fitness and ball control.  Fitness is the easier of the two.

Split your team in half.  Have them line up, in their two teams, one behind each other.  Have them run relay races against each other, out to a marker and back.

Put cones in a circle, a player for each cone, as you walk past a player, tap them on the shoulder, they have to run around the circle and back to the place of the person whose name you shout. Whilst they do this, the person whose name is shouted runs after them.  If they are tagged, they go to the centre of the circle, if they win, they remain and the other goes to the middle.
Repeat until one is left.

Pair up team mates and have them run in a group of pairs, they jog around together.  As you shout left, they touch the floor with their left hands, as you shout right, they touch the floor with heir right hands.  When you shout back to front, the back pair sprint to the front.  You can also shout front to back, and the whole team sprints past the front two.