Mirror run
This one will develop a lot more than just your cardio capability. It's a variant on follow-the-leader, except this time, the leader takes off with variations in gait: skipping, hopping, slaloming, leaping, leaning, twisting and so on. Any combination of posture and locomotion is acceptable. The partner simply follows a few paces behind and tries to duplicate exactly what he sees in front, down to the smallest detail.
You'll probably want to limit this run to a short course. It's surprisingly robust, espcecially for the follower. You can also try it with the leader running backwards.
In any case, if you're the follower, keep your attention focused on your leader's hips and torso. If you're the leader, look for something comprehensible. If your movements are too chaotic or random, your follower will get lost. And finally, don't forget to include occasional ground touches; this will add some power and hip flexibility to the mix.
