Exercises for Children

I'm really not a fan of children using heavy resistance. Their growing bodies and smaller bones may not be able to take the workload as an adult.
So when training children (not special populations) use exercises utilizing;
-jumping
-running
-skipping
-dancing
-socializing or team
-audio responses
-variety
-short term goals (counting)

Children often are bored quickly so short periods & rotation activities may help keep them in the game.

Simple Cardio Interval

The science behind this is; your body is like an airplane you use a lot of fuel at first, then it starts to cruise on the treadmill. By changing the speed often its like in town driving. You use more gas slowing down & speeding up. We turn homeostasis into hyperstasis. But you can build your own sets. 10min, 20, 30, 40 etc.

Simple Cardio Interval

10 minute Sets (treadmill, jogging or elliptical)
-6 minutes @ 60%
-2 minutes @ 80%
-2 minutes @ 30%

Eventually try 3min@60%, 6@80% and 1@30%

If you just roll away in a treadmill, bike, or elliptical you do your
self little good. Your body will compensate quickly.
*to trainers; I'm aware that the recovery is 4x longer than
reccomended. This is purposeful.