The Benefits of Fartlik Training for Athletes

The original fartlik training was I have this loop and I've got some hills and I'm going to run up hard it. And then I'mgoing to run steady and then I'm going, you know, go hard on this field. It's no different than Saraty's kind of loops on his sand dunes. We're always trying to play that balance of how much learning exposure can we get for an athlete at a certain pace?