[tassl]

For your last sentence, I think that you have never trained track and field. While 30-40 minutes of jogging is usually done by athletes, the core training is done by series of shorter distances that you have to compete with.

As an example, I have been training for 400m the last years. Being a short distance (although when you reach 300m you feel that is way too long) it is basically trained by repetitions of shorter distances (150/300). And by basically I mean that sometimes there will be longer distances (specially off-season) and tempo.

In general, people that train for 5000, 10000m don't run 1h to train their endurance. They will do, for example, 25x400m r:30", or shorter distances like 3000, 2000 or 1000.

There is no secret on that, you are using your body to run a higher pace that is used to, while running 1h will make your body be used to this slower pace and thus you will not improve your endurance.

If you ask me, I would say that endurance training is not worth it, and that training high intensity is better for your body.