The story so far

It starts unremarkably. Evening runs of four or five kilometres, mostly between half past five and half past six, when Bangkok is still holding the day's heat. 96 kilometres in the month.

Nothing here suggests a marathon. That is rather the point — this is what the beginning of one actually looks like.

Runs stretch to eight and nine kilometres. Then twelve. Then, on 23 November, 14.8 kilometres in one go — over two hours on your feet.

213 kilometres across the two months. Osaka has a date on it now, and the training has started to look like training.

On 21 December you run 21.2 kilometres in 2:42:05. A half marathon, in training, unprompted by a start line.

That is the run where the marathon stops being an idea.

137 kilometres. A 25.1 kilometre long run on 25 January that still stands as the longest you have ever run outside a race.

Everything is pointing the right way. Four weeks to Osaka.

Through halfway in 2:37:00, which is 7:26 per kilometre. Through 30 km in 3:50:07, still holding 8:13. Then the last twelve kilometres take 1:56:22, at 9:33.

Finish: 5:46:29. A marathon finisher, which nobody can take away.

Average heart rate 144, max 158. Zone 2 tops out at 146 and zone 5 starts at 176. The engine was never the problem — the legs were. The second half was 32 minutes slower than the first.

Read that again, because it is the most useful sentence in this whole diary. You did not blow up because you were unfit. You blew up because your legs had never been asked to do that before. That is a fixable problem, and fixing it is what the next 24 weeks are for.

March: 35 kilometres, down from 137. April is not much better. The running never stops, but it never really starts again either — six months of twenty-kilometre weeks with the odd good fortnight in between.

The longest run in that entire stretch is 13.2 kilometres, on 21 June.

This is the most common thing in distance running and it is worth naming rather than hiding: after a goal race, without a new one, the training flattens out. There is no blame in that chapter. There is just a decision at the end of it.

162 days to Kyoto. You could have picked 5:30 and been fairly safe. You picked sub-5:00, which is 46 minutes faster than Osaka and a pace quicker than you have ever held for a half marathon.

So the plan does not pretend. It builds you toward sub-5:00 and it checks, four times, whether the number is still honest — a 5 km in week 7, a 10 km in week 13, a 30 km with race pace on the end in week 15, and a half marathon in week 19 that settles it.

If the answer is yes, you race sub-5:00. If it is no, you step down to a target you can hold and you still run the best marathon of your life. Both endings are good. Only one of them involves finding out at 32 km.

Unwritten. Nine o'clock in the morning, Takebishi Stadium, about four degrees. The hills come early at Arashiyama and the sting comes late at 38 kilometres.

This chapter gets written by the 24 weeks in front of it.