12-Week Chicago Marathon Training Plan

Chicago, ILOctober 11, 2026

Start around July 19, 2026. The calendar below gives each phase a real date, then the course guidance shows where to make the build specific to Chicago Marathon.

Chicago is the flat, fast American major: a single loop out of Grant Park through more than two dozen neighborhoods, wall-to-wall crowds, and a course where world records have fallen. If you have a time goal, this is a course that will let you chase it.

Race day
October 11, 2026
Start window
July 19, 2026
Runway
12 weeks
Course
a flat loop through 29 neighborhoods
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 Chicago 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 20, 2026–Aug 2, 2026

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

Build

Weeks 3–7

Aug 3, 2026–Sep 6, 2026

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

Peak

Weeks 8–10

Sep 7, 2026–Sep 27, 2026

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

Taper

Weeks 11–12

Sep 28, 2026–Oct 11, 2026

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 Chicago 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 Chicago

Flat and fast means rhythm. Chicago rewards long runs with sustained goal-pace segments; the ability to lock a number and hold it for an hour-plus is the entire skill. Stride’s time-goal builds put that work in your week at the right dose for your volume history.

It’s an October race, so you’ll build through summer heat and race in (usually) cool air, though Chicago Octobers have served up everything from 35°F to 80°F. Train by effort, plan clothing for a range, and rehearse fueling at goal pace, because a flat course lets you run fast enough to make your stomach the limiter.

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 October 11, 2026.

Build My Plan

12-week Chicago Marathon plan questions, answered.

When should I start a 12-week Chicago Marathon plan?

The 2026 Chicago Marathon is scheduled for October 11, 2026, so the 12-week window opens around July 19, 2026. 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 Chicago 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 Chicago 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. Flat and fast means rhythm. Chicago rewards long runs with sustained goal-pace segments; the ability to lock a number and hold it for an hour-plus is the entire skill. Stride’s time-goal builds put that work in your week at the right dose for your volume history.

What if the 12-week Chicago 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 long do I need to train for the Chicago Marathon?

Most Stride marathon plans run 12 to 20 weeks depending on your base and goal. Get matched in the app and every week from today to race day in Grant Park gets mapped, long runs, step-back weeks, and taper included.

Is Chicago a good marathon for a PR or a BQ?

One of the best in the world. The course is flat, the crowds carry you, and October in Chicago is usually cool. If you pace evenly and your buildup included real goal-pace work, Chicago will give you everything your fitness has.

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.