I was shit at and hated PE at school. Looking back I realise that the education part was non existant. In cross country running at no point did they actually attempt to teach you how to run. Nothing in the whole thing improved your fitness. In the winter we did rugby (stand in shorts and t-shirt in a cold field attempting not to be hit by other people), football (similar with less punching), hockey (similar but we armed them with sticks) etc. At least in the summer you could lie on the grass and fail to play cricket.

At no point did I learn about any of the things you need to know about in order to actually get fit, interval training, threshold running, endurance, cross training etc.