Notes on running your first half marathon

The half marathon is the distance where the training stops being optional. You can finish a 10k on enthusiasm and general fitness. Twenty-one kilometres will find whatever you skipped.

Go slower

The most common mistake in a first training block is running every session at roughly the same moderately hard effort. It feels productive and it produces a plateau followed by an injury.

The structure that works is unglamorous: two easy runs at a pace where you could hold a conversation, and one longer run that increases by about ten percent a week. That is it for the first eight weeks.

If you can't talk in full sentences on an easy run, it isn't an easy run.

The last three weeks

Peak long run around eighteen kilometres, then taper. The taper is where discipline gets tested, because you will feel fresh and want to prove something ten days out. Do not.

Race day: start slower than your target pace for the first three kilometres. Everyone who runs a good first half says this and almost nobody does it.

• Nothing new on race day — shoes, food, or clothing.
• Practise drinking while moving; it is harder than it looks.
• Plan for the fifteen-kilometre wall before you hit it.