Runsy
Training plans

12-week half marathon training plan — beginner

A free 12-week half marathon plan for beginner runners: 3 runs a week, peaking at 35 km, with cutback weeks and a real taper.

12 weeks

Length

3

Runs / week

35 km

Peak week

19 km

Longest run

WeekPhaseSessionsLong runTotal
1base
  • Tueeasy5km
  • Thusteady4km
  • Sunlong run10km
10km19km
2base
  • Tueeasy5km
  • Thusteady4km
  • Sunlong run11km
11km20km
3base
  • Tueeasy6km
  • Thusteady5km
  • Sunlong run13km
13km24km
4cutback
  • Tueeasy4km
  • Thusteady3km
  • Sunlong run9km
9km16km
5build
  • Tueeasy6km
  • Thusteady5km
  • Sunlong run14km
14km25km
6build
  • Tueeasy7km
  • Thusteady6km
  • Sunlong run16km
16km29km
7build
  • Tueeasy8km
  • Thusteady6km
  • Sunlong run17km
17km31km
8cutback
  • Tueeasy5km
  • Thusteady4km
  • Sunlong run12km
12km21km
9peak
  • Tueeasy9km
  • Thusteady7km
  • Sunlong run19km
19km35km
10taper
  • Tueeasy5km
  • Thueasy4km
  • Sunlong run12km
12km21km
11taper
  • Tueeasy4km
  • Thueasy3km
  • Sunlong run8km
8km15km
12race
  • Tueeasy5km
  • Thushakeout3km
  • SunRACE DAY21.1km
21.1km29.1km

Who this plan is for

This is the beginner version — it assumes you can run 5 km without stopping and want to finish comfortably. It runs 12 weeks, 3 days a week, and peaks at 35 km in the hardest week.

If that sounds like too much or too little, the same half marathon block exists at other levels and lengths — the related plans below are the same engine with different inputs.

How the plan is built

Cutback weeks. Roughly every fourth week drops to about 70% of the previous long run. Adaptation happens during the easier week, not the hard one.

Progression is capped at 20%. No week's long run climbs more than a fifth above the last progressive week. Where a shorter plan cannot reach the usual peak inside that limit, it arrives at a lower peak rather than taking an unsafe step.

A real taper. The closing weeks come down hard, and race week carries almost nothing — two short shakeouts totalling 8 km before the start line.

This plan, but it adapts

7-day free trial, then $12.99/mo.

7-day free trial · then $12.99/mo · cancel anytime

Fair questions

How many miles a week is this half marathon plan?

It peaks at 35 km (about 22 miles) in the hardest week, and totals roughly 285 km across the 12 weeks.

What is the longest run in a 12-week half marathon plan?

19 km. Long runs exceed race distance at this event because the limiter is aerobic base, not distance.

Is 12 weeks long enough to train for a half marathon?

For a beginner runner, yes — provided you are starting from the base this plan assumes. If you are not, the longer version of this plan is the more forgiving choice, mainly because it absorbs missed weeks better.

Is this plan free?

Yes. Every week is on this page. The subscription is for the app, which adapts the plan around the sessions you actually complete.

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