Your plan in four answers
Set for October 17, 2027, about 51 weeks out.
- Distances
- Marathon, Half marathon
- Terrain
- Hilly
- Taper starts
- September 29, 2027
Course
The MDI Marathon course
This is a point-to-point course: the marathon starts at 8:00 a.m. on Main Street in downtown Bar Harbor and finishes in the maritime village of Southwest Harbor, while the half starts at 8:30 a.m. at the marathon's halfway point in Northeast Harbor. After a slightly downhill first mile, marathoners climb about 150 feet from mile 1 to mile 3 over the ridge between Champlain and Dorr Mountains, then sweep down to Otter Creek and the sea, roll along above Seal Harbor, and reach the mouth of Somes Sound, the only fjord on the Eastern Seaboard, at halfway.
Read the full course notes
The low point comes at mile 16 on the east shore of the sound, followed by a sharp climb from mile 17 to 18, a downhill at mile 19 and a gradual ascent from Somesville at mile 20 to the high point at mile 25. The final 1.2 miles run all downhill into Southwest Harbor, with Acadia National Park in peak fall color all around. Parts of the course stay open to traffic, and the certified distance is measured on the left side of the road, facing traffic.
- Terrain
- Hilly
- Distances
- Marathon, Half marathon
- Weather on race day
- According to the organizers, race day has historically ranged from a low of about 39 °F to a high of about 57 °F, averaging 47 °F. Expect a chilly start in Bar Harbor, so dress in layers you can shed and keep drinking even when the air feels cool.
What to train for
MDI's challenge is the back half: a sharp climb from mile 17 to 18 and a gradual five-mile ascent from mile 20 to 25.
Build long runs that finish on a long, gentle uphill, for example the last 4 to 6 miles of an 18 to 20 mile run on a steady grade at marathon effort.
Add weekly hill repeats (6 to 10 x 60 to 90 seconds) for the mile 17 climb, and practice relaxed downhill running, since miles 3 to 6, 7 to 9 and the final 1.2 miles all descend. Pace by effort rather than by the watch; the 6.5-hour limit (15-minute miles) leaves room to enjoy the views.
Sample week
A sample MDI Marathon training week
A week from the middle of the build, about six weeks out. Your plan sets the real distances and paces from your own fitness and adjusts them every week as you train.
- Monday
- Rest, or 20 minutes of mobility
- Tuesday Key session
- Hill repeats: 10 × 90 s up a steady grade, jog back down
- Wednesday
- Easy run, 6–7 mi
- Thursday Key session
- Goal-pace run, 10 mi with 6 mi at race pace
- Friday
- Recovery run, 4 mi, or cross-train
- Saturday Key session
- Long run, 16–18 mi on hilly ground, steady effort on the climbs
- Sunday
- Easy run, 4 mi, then 6 relaxed strides
Your build to race day
Taper
Tapering for the MDI Marathon
Start the taper two to three weeks before race day. Cut your weekly volume by about a third, then by half in race week, and keep a few short efforts at race pace so your legs stay sharp. The course is hilly, so keep one short hill session in the first taper week to keep the climbs familiar. With the race on October 17, 2027, your taper starts around September 29, 2027.
Also in Claude
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Add AthleteSpace to Claude once, then paste this prompt and put in your own numbers.
Build me a training plan for the Mount Desert Island Marathon, Half & Relay on October 17, 2027. I run [distance] a week, [days] days a week, easy pace [pace].
MDI Marathon training questions
How long should I train for the MDI Marathon?
Most runners give a marathon sixteen to twenty weeks of focused training on top of an existing base. The plan above counts back from your actual race date, so if you have less time than that it builds the best plan the remaining weeks allow rather than pretending you have longer.
Is the MDI Marathon course hilly?
Hilly. This is a point-to-point course: the marathon starts at 8:00 a.m. on Main Street in downtown Bar Harbor and finishes in the maritime village of Southwest Harbor, while the half starts at 8:30 a.m. at the marathon's halfway point in Northeast Harbor.
What is the weather usually like at the MDI Marathon?
According to the organizers, race day has historically ranged from a low of about 39 °F to a high of about 57 °F, averaging 47 °F. Expect a chilly start in Bar Harbor, so dress in layers you can shed and keep drinking even when the air feels cool.
When should I start tapering for the MDI Marathon?
Start the taper two to three weeks before race day. Cut your weekly volume by about a third, then by half in race week, and keep a few short efforts at race pace so your legs stay sharp. The course is hilly, so keep one short hill session in the first taper week to keep the climbs familiar. With the race on October 17, 2027, your taper starts around September 29, 2027.
Do I need an account to get a MDI Marathon training plan?
No. The plan above builds in your browser with no account, no email, and no card. Make a free account only if you want to keep it, log your runs against it, and have the coach keep adapting it as your training goes.