The aerobic system decides your eight hundred, not your kick

Middle distance runners keep training the last two hundred metres of a race that is won much earlier.

Two laps looks like a speed event and gets trained like one in most programmes I have seen. That is the mistake. By the time an athlete comes off the final bend, the majority of the energy they have burned has come from oxidative work, and the size of that contribution grows every year past about the age of eighteen. The kick is the visible part. It is not the deciding part.

Here is the mechanism, roughly. Anaerobic glycolysis gives you a lot of power very quickly and it runs out fast, and what it leaves behind is a chemical environment that makes muscle contraction progressively less efficient. The aerobic pathway is slower to spin up but it also clears the mess. An athlete with a bigger aerobic base is not simply fitter over the last fifty metres. They arrive at the last fifty metres having spent less. Same race, different bank balance.

So why does everyone still hammer repetition two hundreds in October? Because the pathway that fails first feels like the pathway you should train. It hurts at the end, so you train the end. Intuitive, and wrong in the same way that treating a bad back with painkillers is wrong.

I want to be careful, because the opposite error is real too. Runners who do nothing but steady volume become tourists at eight hundred pace. They can hold a comfortable rhythm all day and cannot produce the ugly, ragged output that the first lap of a championship final demands. Speed is a skill of coordination as much as a pathway and it goes stale quickly. You cannot bank it in April and cash it in August.

The split I would defend, and people do argue with me about it, is that the anaerobic work should be small, late and precisely aimed, while the aerobic work is large, early and boring. Twelve weeks of unglamorous threshold and easy volume. Then six weeks where the sharp sessions get inserted into a body that can actually recover between them.

The test is simple enough. Run a hard first lap in training and time the second. If the second collapses by four seconds, the problem is not a missing kick. The problem is that everything got spent on the way to the bell, and no amount of finishing speed work will fix a fuel bill incurred four hundred metres earlier.