20-Week Tunnel Vision Marathon Training Plan

North Bend, WAAugust 8, 2027

Start around March 21, 2027. The calendar below gives each phase a real date, then the course guidance shows where to make the build specific to Tunnel Vision Marathon.

The Tunnel Vision Marathon spends all 26.2 miles going downhill on an unpaved rail trail in the Cascades, and partway along you run into the Snoqualmie Tunnel and out the other side. The organizers describe approximately 1,000 feet of net downhill, and the course descends roughly four feet for every one it climbs.

Race day
August 8, 2027
Start window
March 21, 2027
Runway
20 weeks
Course
Downhill · Point to Point
Plan choice
Current training

Does this window fit your starting point?

Use the longer window to make the early build calmer, not to add five months of hard training. The plan should begin close to your current load, hold most running easy, and delay the biggest race-specific work until the middle of the cycle.

  • You want a longer foundation phase before marathon-specific training.
  • Your current mileage is steady but below the load you expect to carry later.
  • You prefer gradual long-run growth with regular step-back weeks.
  • You can sustain a five-month routine without turning every week into a peak week.

The 20-week Tunnel Vision 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.

Foundation

Weeks 1–6

Mar 22, 2027–May 2, 2027

Set the routine, grow easy volume gradually, and finish each week with enough control to repeat it.

Build

Weeks 7–13

May 3, 2027–Jun 20, 2027

Extend the long run, introduce race-specific terrain, and keep recovery weeks on the calendar.

Peak

Weeks 14–17

Jun 21, 2027–Jul 18, 2027

Complete the most demanding race rehearsals and settle fueling, pacing, shoes, and clothing before taper begins.

Taper

Weeks 18–20

Jul 19, 2027–Aug 8, 2027

Reduce the load, keep familiar running in the week, and let the work from the previous four months show up on race day.

Make the window specific to Tunnel Vision Marathon.

Build general durability first. Add the race's hills, flat sustained running, downhill exposure, heat, or humidity in layers after the weekly rhythm is stable, then make the final long runs the most course-specific.

Read the full race guide

How to train for the Tunnel Vision Marathon

Train your quads to absorb downhill running, because that's the whole race. A runner who prepares for this course on flat roads shows up with fit lungs, a good heart rate and legs that stop working after mile 18, when a couple of hours of accumulated descent has done its damage. No amount of aerobic fitness substitutes for that specific durability.

Start early and build gradually. From about 12 weeks out, put two to four miles of sustained gentle downhill into one run a week at goal effort, adding distance rather than steepness as you go. Run it with a quick, short stride and let gravity work instead of braking. Real soreness the first few times is the point of the exercise.

Then rehearse the surface. This is a trail race, not a road race, so do a meaningful share of that downhill work on packed gravel or dirt. Unpaved footing asks more of your stabilizers and slightly changes your stride, and finding that out on race day while descending is a bad plan.

Last, practise restraint in the first hour. The grade will hand you splits that look like a breakthrough. Pick a goal effort, run the first ten miles at it even when the watch says you could give more, and you'll still have quads at mile 22 when everyone around you doesn't.

Tunnel Vision Marathon course facts

Course
Point to Point · Downhill · Trail
Elevation gain / loss
267 ft gain, 1,137 ft loss
Net elevation drop
About 870 ft lower at the finish than the start
Highest / lowest point
2,578 ft / 1,696 ft
Marathon finishers
235 in 2026 (very small field)
Boston qualifier
Certified Boston qualifying course
Finishers running a qualifying time
20.4% in 2026
Typical race morning
58°F at the start, 81% humidity, clear
Race day high / low
77°F / 54°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 August 8, 2027.

Build My Plan

20-week Tunnel Vision Marathon plan questions, answered.

When should I start a 20-week Tunnel Vision Marathon plan?

The 2027 Tunnel Vision Marathon is scheduled for August 8, 2027, so the 20-week window opens around March 21, 2027. Treat that as the outside edge of the window, then line week one up with the plan's normal weekly rhythm.

Is a 20-week plan long enough for the Tunnel Vision Marathon?

Use the longer window to make the early build calmer, not to add five months of hard training. The plan should begin close to your current load, hold most running easy, and delay the biggest race-specific work until the middle of the cycle. 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 Tunnel Vision Marathon course in 20 weeks?

Build general durability first. Add the race's hills, flat sustained running, downhill exposure, heat, or humidity in layers after the weekly rhythm is stable, then make the final long runs the most course-specific. Train your quads to absorb downhill running, because that's the whole race. A runner who prepares for this course on flat roads shows up with fit lungs, a good heart rate and legs that stop working after mile 18, when a couple of hours of accumulated descent has done its damage. No amount of aerobic fitness substitutes for that specific durability.

What if the 20-week Tunnel Vision 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.

How steep is the Tunnel Vision Marathon?

Gentle but constant. The race describes approximately 1,000 feet of net downhill spread across 26.2 miles of rail trail, descending roughly four feet for every one it climbs. No section is steep. The difficulty is that the descent never stops, so your quads do the same eccentric work for the entire race.

Is the Tunnel Vision Marathon a good Boston qualifier?

Yes, one of the better ones. 20.4% of finishers ran qualifying times in 2026, 33.5% in 2025 and 34.6% in 2024. The organizers state the marathon carries no time penalty under Boston's net downhill rules, though that ruling is worth confirming with the BAA for your entry year.

Put the 20-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.