Your plan in four answers
Set for September 26, 2027, about 48 weeks out.
- Distances
- Marathon, Half marathon
- Terrain
- Rolling
- Taper starts
- September 8, 2027
Course
The Clarence DeMar Marathon course
The full marathon starts at 7:00 a.m. on Main Street in Gilsum and the half at 8:00 a.m. at Surry Mountain Lake beach in Surry, and both finish on the historic Appian Way at Keene State College, steps from where Clarence DeMar coached. Marathoners run through quiet New Hampshire countryside to the Surry Mountain Dam, where an out-and-back section lets you high-five other runners, then pass Bretwood Golf Course on the way into Keene.
Read the full course notes
There is a net drop from start to finish, and the first half is mostly gentle rolling hills. The real work comes later: a long climb in mile 15, then short, steeper climbs in mile 22 and mile 24 through Greenlawn and Woodland cemeteries. Both courses are USATF certified, the marathon is a Boston qualifier, and staffed water stations come about every 1.5 miles.
- Terrain
- Rolling
- Distances
- Marathon, Half marathon
- Weather on race day
- Late September in the Keene area usually brings crisp mornings in the 40s to low 50s °F at the 7:00 a.m. start, warming into the 60s or low 70s °F by early afternoon. A warm, sunny day is possible in early foliage season, so bring a throwaway layer and be ready to ease your pace if it heats up in the final miles.
What to train for
DeMar saves its hills for the second half, so train to climb on tired legs.
Put a sustained 3 to 5 minute hill around miles 13 to 15 of your long runs, and finish 18 to 20 mile runs on rolling roads with two short, steep efforts in the last 4 miles to rehearse miles 22 and 24.
Once a week, run 6 to 8 x 60 to 90 seconds uphill at 10K effort. The early net descent invites a fast start, so run the first 10 miles of long runs 10 to 15 seconds per mile slower than goal pace and keep something for Keene.
Sample week
A sample Clarence DeMar 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
- Intervals: 5 × 1 mile at 5K to 10K effort, easy jog between
- 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, the last 4 mi at race pace
- Sunday
- Easy run, 4 mi, then 6 relaxed strides
Your build to race day
Taper
Tapering for the Clarence DeMar 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 rolls, so keep one short session on undulating ground in the first taper week. With the race on September 26, 2027, your taper starts around September 8, 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 Clarence DeMar Marathon & Half Marathon on September 26, 2027. I run [distance] a week, [days] days a week, easy pace [pace].
Clarence DeMar Marathon training questions
How long should I train for the Clarence DeMar 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 Clarence DeMar Marathon course hilly?
Rolling. The full marathon starts at 7:00 a.m. on Main Street in Gilsum and the half at 8:00 a.m. at Surry Mountain Lake beach in Surry, and both finish on the historic Appian Way at Keene State College, steps from where Clarence DeMar coached.
What is the weather usually like at the Clarence DeMar Marathon?
Late September in the Keene area usually brings crisp mornings in the 40s to low 50s °F at the 7:00 a.m. start, warming into the 60s or low 70s °F by early afternoon. A warm, sunny day is possible in early foliage season, so bring a throwaway layer and be ready to ease your pace if it heats up in the final miles.
When should I start tapering for the Clarence DeMar 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 rolls, so keep one short session on undulating ground in the first taper week. With the race on September 26, 2027, your taper starts around September 8, 2027.
Do I need an account to get a Clarence DeMar 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.