12-Week Clarence DeMar Marathon Training Plan

Keene, NHSeptember 26, 2027

Start around July 4, 2027. The calendar below gives each phase a real date, then the course guidance shows where to make the build specific to Clarence DeMar Marathon.

The Clarence DeMar Marathon starts at 7:00 a.m. in Gilsum, New Hampshire, a village of a few hundred people, and finishes 429 feet lower on Appian Way at Keene State College. In between it runs past Surry Mountain Dam and Bretwood Golf Course, and it spends miles 22 to 24 inside the Greenlawn and Woodland cemeteries, where the road climbs.

Race day
September 26, 2027
Start window
July 4, 2027
Runway
12 weeks
Course
Downhill · Point to Point
Plan choice
Current training

Does this window fit your starting point?

Use this window when your recent training is steady and the opening week will not be a mileage jump. If you are returning after a long break, twelve weeks is too little room to rebuild and peak at the same time.

  • Your weekly mileage has been consistent for the last six to eight weeks.
  • You have completed recent long runs and do not need to rebuild from three easy miles.
  • You can protect the same number of run days from week one through race week.
  • You are prepared to begin race-specific work early instead of using a long base phase.

The 12-week Clarence DeMar Marathon calendar

These dates define the job of each phase. Your current mileage, recent longest run, experience, goal, and available days still decide the actual workouts inside them.

Settle

Weeks 1–2

Jul 5, 2027–Jul 18, 2027

Hold close to your current volume, establish the weekly rhythm, and make sure the opening load is honest.

Build

Weeks 3–7

Jul 19, 2027–Aug 22, 2027

Grow the long run and weekly work with step-back weeks intact. There is no room to repay missed mileage.

Peak

Weeks 8–10

Aug 23, 2027–Sep 12, 2027

Complete the most race-specific long runs, rehearse fueling, and practice the terrain that will decide the final 10K.

Taper

Weeks 11–12

Sep 13, 2027–Sep 26, 2027

Reduce volume, keep the routine familiar, and arrive on race day without trying to squeeze in one more big week.

Make the window specific to Clarence DeMar Marathon.

Course-specific work starts early in a 12-week build. Put the race's terrain and expected conditions into long runs once the opening weeks feel controlled, without adding extra hard days.

Read the full race guide

How to train for the Clarence DeMar Marathon

Train for the Clarence DeMar Marathon as a downhill race with an uphill finish, which is an unusual combination and the reason a generic plan fails here. You need quads that can absorb about 1,100 feet of cumulative descent and still produce force on climbs at miles 22 and 24, when most runners have nothing left to give.

Start downhill work early, at least eight weeks out, and build it slowly. Descents cause eccentric muscle damage and the adaptation to it is slow, but it's real. Run repeats on a moderate grade at goal effort with a short quick stride and no heel braking. Then, and this is the part almost everyone skips, put a climb at the end of your long run.

A good session for this course looks like two hours of rolling running, a sustained descent through the middle, and two short hard hills inside the last twenty minutes. That's race day compressed into one workout. If you can hold your form on those closing hills, the cemeteries at mile 22 will feel like something you already rehearsed.

Clarence DeMar Marathon course facts

Course
Point to Point · Downhill · Road/Pavement
Elevation gain / loss
706 ft gain, 1,135 ft loss
Highest / lowest point
928 ft / 495 ft
Marathon finishers
308 in 2025 (small field)
Boston qualifier
Certified Boston qualifying course
Finishers running a qualifying time
14.3% in 2025
Typical race morning
51°F at the start, 88% humidity, clear
Race day high / low
68°F / 42°F on average

Sources

Let your current training decide the actual plan.

Current mileage, recent longest run, marathon experience, goal, and available days determine which plans rank first. After you choose and subscribe, Stride dates every workout through September 26, 2027.

Build My Plan

12-week Clarence DeMar Marathon plan questions, answered.

When should I start a 12-week Clarence DeMar Marathon plan?

The 2027 Clarence DeMar Marathon is scheduled for September 26, 2027, so the 12-week window opens around July 4, 2027. Treat that as the outside edge of the window, then line week one up with the plan's normal weekly rhythm.

Is a 12-week plan long enough for the Clarence DeMar Marathon?

Use this window when your recent training is steady and the opening week will not be a mileage jump. If you are returning after a long break, twelve weeks is too little room to rebuild and peak at the same time. The course does not change the opening load you can handle, so choose from your current mileage and recent longest run before adding race-specific terrain.

How should I prepare for the Clarence DeMar Marathon course in 12 weeks?

Course-specific work starts early in a 12-week build. Put the race's terrain and expected conditions into long runs once the opening weeks feel controlled, without adding extra hard days. Train for the Clarence DeMar Marathon as a downhill race with an uphill finish, which is an unusual combination and the reason a generic plan fails here. You need quads that can absorb about 1,100 feet of cumulative descent and still produce force on climbs at miles 22 and 24, when most runners have nothing left to give.

What if the 12-week Clarence DeMar Marathon window has already started?

Do not double weeks or cram missed mileage into the remaining calendar. Use your current mileage, recent longest run, experience, goal, and available days to choose a plan that can enter at an appropriate point while preserving the taper.

Is the Clarence DeMar Marathon downhill?

Net downhill, yes, by about 429 feet from Gilsum to Keene. But it isn't a straight descent. The organizers describe mostly gentle rolling hills through the first half, a long climb at mile 15, and steeper climbs at miles 22 and 24, so the hardest running comes late rather than early.

Is the Clarence DeMar Marathon a good Boston qualifier?

Yes, one of the better small-race options. 14.3% of finishers ran a Boston qualifying time in 2025 and 11.3% in 2024, with rates near 20% in 2021 and 2022. The course is USATF certified and its net drop is not large enough to trigger the BAA's downhill adjustment.

Put the 12-week window against your actual race.

Each page counts back from race day, maps the 4 phases to real dates, and applies the window to that course and its typical conditions.