Is There a Better Way to Train Your Body Than a Whacky Idea?

In the days of low level erobic training, i was trying to train the body to be more efficient burning fat by reducing the training load a at a lower heart rate. Zac bitters is one of the best ultra runners ever to live and trains on a he trains quito, and he e sets world records. He does events, sometimes without eating anything, or very much at all, because he's so good with his metabolic flexibility.