How long should marathon training be?
| Runner | Marathon | Half marathon | Before week 1 you should… |
|---|---|---|---|
| New to racing | 20–24 weeks | 12–16 weeks | run 3 times a week, about 30 minutes each |
| Regular runner | 16–18 weeks | 10–12 weeks | run 25–40 km (15–25 mi) a week comfortably |
| Experienced | 12–16 weeks | 8–10 weeks | already have a long run of 16 km+ and steady mileage |
Plan length matters less than the base you bring to week one. Most published plans — including Hal Higdon’s, Pfitzinger’s 18-week plans and the Hansons method — assume you can already run several times a week without pain.
The phases of a training plan
Base
Easy mileage, one long run a week and strides. Build volume slowly — the weekly mileage calculator shows safe increases.
Build
Add threshold and marathon-pace work. Use the VDOT, Pfitzinger or Hansons calculators for paces.
Peak
The longest long runs (typically 29–35 km / 18–22 mi) and highest weekly volume, usually 4–6 weeks before race day.
Taper
Cut volume by roughly 20–40 % a week for 2–3 weeks while keeping some race pace, so you arrive fresh.
Training start dates for the majors
| Race | Race date | 16-week start | 18-week start | 20-week start |
|---|---|---|---|---|
| Boston | Mon 19 Apr 2027 | Mon 28 Dec 2026 | Mon 14 Dec 2026 | Mon 30 Nov 2026 |
| London | Sat 24 Apr 2027 | Mon 4 Jan 2027 | Mon 21 Dec 2026 | Mon 7 Dec 2026 |
| Chicago | Sun 10 Oct 2027 | Mon 21 Jun 2027 | Mon 7 Jun 2027 | Mon 24 May 2027 |
| NYC | Sun 7 Nov 2027 | Mon 19 Jul 2027 | Mon 5 Jul 2027 | Mon 21 Jun 2027 |
| Berlin | Sun 26 Sep 2027 | Mon 7 Jun 2027 | Mon 24 May 2027 | Mon 10 May 2027 |
| Tokyo | Sun 7 Mar 2027 | Mon 16 Nov 2026 | Mon 2 Nov 2026 | Mon 19 Oct 2026 |
| Sydney | Sun 29 Aug 2027 | Mon 10 May 2027 | Mon 26 Apr 2027 | Mon 12 Apr 2027 |
Start dates are the Monday of week 1 so that race day falls at the end of the final week (for Monday races such as Boston, on the day after it). * Expected date, not yet confirmed by the organiser.
Starting late?
If you have fewer weeks than the plan, drop weeks from the start of the base phase rather than squeezing the peak or skipping the taper — and never jump your weekly mileage to “catch up”. If you have more time, repeat a base week or two before week 1.
Last reviewed: September 2026 · Health disclaimer