Seoul Marathon 2027: your 12-week plan, from December 28 to the Gwanghwamun start

Your training, timed for March 21

The plan lasts 12 weeks, starting on Mon, December 28. With more time, it can start on November 30 with 4 lead-in weeks.

1. Weeks 1–3

   Base

   Dec 28 → Jan 17

   Settle volume, wake threshold up

2. Weeks 4–7

   Development

   Jan 18 → Feb 14

   Marathon pace comes in, long runs get longer

3. Weeks 8–10

   Specific

   Feb 15 → Mar 7

   Long blocks at marathon pace, 2-hour-plus runs

4. Weeks 11–12

   Taper

   Mar 8 → Mar 21

   Two weeks to arrive fresh

From Gwanghwamun Square to Jamsil, across the Han River

The 2027 route is not published yet ("To Be Determined" on the official site), but runners are due to gather at Gwanghwamun Square at 6:30 a.m. The organizer describes its course like this: start at Gwanghwamun Square, past Dongdaemun Design Plaza (DDP), across the Han River on Jamsil Bridge, finish at the Seoul Sports Complex in Jamsil. It is Korea's only World Athletics Platinum Label road race.

The 5-hour limit is strictly enforced because roads reopen behind the runners: 5 hours for 26.2 miles is an average of 11:27 min/mi. Water and sports drink every 5 km (about 3 miles), sponges from km 7.5, snacks at km 20 and 30 (miles 12.4 and 18.6).

Three workouts to hold your pace all the way to Jamsil

With no profile published, prepare for what is certain: a city marathon at an even pace, a start in corrals by submitted time and a strict cutoff. Ask your assistant to build these workouts and send them to your watch; it sets the paces from your MAS (maximal aerobic speed).

• — Marathon-pace blocks: 15 min warm-up, 3 × 3 miles at marathon pace (about 77 to 79% of MAS), 2 min jog recovery, 10 min cool-down.
• — Long run with a strong finish: 2 h 15 easy, the last 40 minutes at marathon pace, to keep your rhythm late in the race, after Jamsil Bridge.
• — If your goal is close to 5 hours: within the long run, 3 × 20 min at 10:50 min/mi, a margin of over 30 seconds per mile on the cutoff average.

A midwinter build, starting December 28

Late-March race: the 12-week plan starts on Monday, December 28, 2026, with New Year in week 1, then January and February in the heart of the northern winter. Seoul is 9 hours ahead of London on race day: arriving a few days early leaves time to settle in, especially since overseas runners must collect their race pack in person at the Expo before race day.

Lost a week to the cold or the holidays? Your assistant reviews it (sessions done or missed, training load), decides by the plan's rules whether to repeat the week or move on, and sends the next week to your watch. It can also move a workout in your Garmin Connect calendar.

Entry: a sub-5-hour time required

The marathon requires an official time of 4:59:59 or faster (net time); for overseas runners, it must be set between January 1, 2024 and November 30, 2026. Places for Korea residents sold out in June 2026; overseas registration opened on September 1, 2026, via en.dongma.club, worldsmarathons.com or runnet.jp. Overseas runners submit their proof of time by November 30, 2026, and receive their corral by email before mid-January 2027.

Corrals run from A to H by submitted time: starting ahead of your corral means disqualification. The 10K has no qualifying time.

Frequently asked questions