How to build a half marathon training plan around your real life

Most half marathon plans are written for someone with no job, perfect sleep and no interest in lifting. They are correct and they are useless. Here is the structure that works, and the rules that let it bend without breaking.

The shape of twelve weeks

Three blocks of four weeks: base, build, and sharpen, with a taper inside the last block. Within each block, three weeks climb and the fourth drops volume by about a third. The long run grows from roughly 10 km to 18 or 19 km; one quality session a week (tempo in the base block, threshold intervals in the build, race-pace work in the sharpen) sits mid-week, and everything else is easy. Genuinely easy: conversational, in your lowest two heart-rate zones.

The safety rules that matter more than the sessions

• Ramp rate. Weekly volume rises no more than about ten percent, and the long run no more than 2 km at a time.
• Hard-day spacing. At least 48 hours between the long run and the quality session; a heavy lower-body lift counts as a hard day.
• Down weeks are not optional. The fourth week is where the adaptation lands.
• Taper for real. Volume drops 40 to 50 percent in the last ten days; intensity stays.

Bending around real life

Travel Thursday? The long run moves to Saturday and the quality session to Tuesday; nothing else changes. Two short nights? Cap the quality session at two thirds and keep the rest. Heavy leg day landed on Wednesday? The tempo waits until Friday. The plan is a set of constraints, not a calendar, and the sessions can slide as long as the constraints hold.

Letting a coach hold the constraints

PeakU builds the block toward your race date, audits it for ramp rate and hard-day spacing before it shows you anything, reflows the week when readiness drops or a session slips, and predicts your finish from the training you actually did. When it refuses a plan, it tells you which rule it would have broken.