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Training

Ultra Training Plan: Every Week to Race Day

Ike Lacey October 5, 2026 7 min read

Ultra Training Plan: Every Week to Race Day

Race day is a number of weeks.

That sounds obvious until you try to see it. You sign up in May for a race somewhere past the summer, and the only thing on your screen is this week. Is there time to build? When a build for a 100 miler can run six months, not knowing how far away race day is in weeks is its own kind of worry.

The other worry is quieter. You come back after a year off, or after a season that did not go the way you meant, and the plan in front of you starts from numbers you ran a long time ago. Or it starts at Week 1, as if the ten weeks you have already put in never happened.

NavRun now lays out the whole build. Every week, from today to the start line.


Why an ultra build is different

A road marathon plan is usually a fixed 16 or 18 weeks. An ultra build comes in more shapes. A first 50K, a 100K on a mountain course and a 200 miler ask for different lengths and different tapers (the taper is the stretch of lighter weeks before a race, so you arrive fresh rather than tired).

Distance also stops being a good measure somewhere along the way. Past 100 miles you will spend a day or more on your feet, and hours tell you more about readiness than miles do. Coaches at CTS (Carmichael Training Systems) put it in hours too. Their floor is about 6 hours a week for at least three weeks in a row for a 50K or a 50 miler, and about 9 hours a week for at least six weeks for a 100K or a 100 miler. That is a minimum, not the peak. What NavRun's build aims at is further down.

And most ultrarunners have more than one race on the calendar: a spring 50K on the way to a fall hundred, a local trail race run for fun. The plan has to know about all of them.


What NavRun shows you

Pick your main goal race, which NavRun calls your A race, and NavRun shows the whole build before anything changes. Nothing is written until you say so.

Web. Free.

Every week to race day. Each row is a week, with time on your feet and miles, and a label for what that week is for:

  • Base: "Easy running and time on your feet."
  • Build: "The long days grow toward race day."
  • Peak: "Your biggest weeks of this build."
  • Taper: "Less running, so you reach race day fresh."
  • Easier week: "A lighter week, so the work can settle in." Every third or fourth week steps back.

If your race is far enough out that the build has not started, the first weeks read "Holding steady": steady weeks until the build begins.

Weeks you have already run count. If you have been training for ten weeks, the plan reads "Week 11 of 12 ยท 9 days to race day", not "Week 1". NavRun looks back through your running to find when this build really began.

Four weeks at a time. Say yes ("Use this build") and the next four weeks are written for you, day by day. The weeks after that fill in as you go, from the running you log. A missed week does not break the plan. It becomes part of what the next weeks are built from.

Your other races fit inside. Your other races stay in the build as training races, run as part of the work rather than tapered for, and a bigger one gets "Easier week after" it. Pick a different A race and you see the new build first. The old A race becomes a B race, a race you care about that is not the one the whole build aims at.

When a race moves, it asks. If a race changes date or distance, NavRun shows you the new build and waits for your answer. "Keep my current build" is always one of the buttons.

What the build aims at

There is an old rule of thumb in ultrarunning, credited to David Horton: you should be able to run in a week what you will run on race day. For a 50K, a 50 miler or a 100K, the peak weeks of the build aim at the race distance in a week: about 31 miles, 50 or 62. It does not always hold for 100 milers and longer, so there the build counts hours instead: about ten a week at its biggest for a hundred, twelve for a 200 (and no more than 90 miles in a week).

If there is not enough time to get there safely, the build says so ("This build grows as far as your recent running allows") and does not stack miles to force it. The weekly increase is yours to set.

Coming back

If it has been three weeks or more since your last run, the build starts at about half of the best steady stretch you ran before the break, then gives you two "Rebuilding" weeks: "A steadier week with your usual days and nothing hard, before the build climbs again." The line at the top of the build reads: "This build starts from the running you are doing now." It does not ask where you were.

No history at all? The first weeks start small and grow with the running you log.


Two changes that shape every build

Your taper is three settings. A, B and C races each get their own taper length on your preferences page, and each setting shows your next race of that kind and what it does to that week. Zero is a real answer: a C race set to zero keeps the week whole. A race of 50 miles or more keeps at least three days of taper whatever the setting says.

Web. Free. The iPhone app shows the taper for the race in front of you.

Hikes stop counting as running miles. A long day of hiking used to push up how far the plan asked you to run the next week. Now that ceiling comes from your running, road and trail, and your hikes count as hours on your feet, which the plan still knows about. If you power hike the climbs, and most of us do, this matters. (More on that in power hiking for ultras.)

Web and iPhone. Free.


What it does not do yet

The whole build lives on the web. The iPhone app shows the weeks already written and your recent weekly miles toward a race, but not the full build to race day yet.

Timed races, a backyard ultra or a 24 or 48 hour, have no distance, and the build needs one to size the weeks. So there is no whole-block build for a timed race yet. NavRun tells you that rather than guessing.

A race more than a year out gets a build once it comes within a year.


How to lay out a build by hand

You need a calendar and a pencil.

  1. Count the Mondays. Start at race week and count back to this week. That number is your build.
  2. Mark the taper first. About two weeks for a 50K to a 100K, three for a 100 miler, closer to a month for a 200. The ultra taper guide goes deeper.
  3. Mark the peak. The three to six weeks before the taper are your biggest. Aim them at the race distance in a week, or at hours for a hundred and longer.
  4. Put in easier weeks. Every third or fourth week, run less.
  5. Fill the front with base. Easy running, with time on feet over pace. If the base is short, keep the taper whole and let the peak be smaller.
  6. Place your other races. Run them as training days, then take an easy week after the big ones.
  7. Coming back? Start well under where you were and hold there a couple of weeks before building. Relentless Forward Commotion suggests treating it like your taper in reverse.

If this is your first, the first 50K training guide goes week by week.


Common Questions

How many weeks do I need to train for an ultra?

A full NavRun build is 16 weeks for a 50K, 20 for a 50 miler or 100K, 24 for a 100 miler and 28 for a 200. Less time still gets a build: it has less base, and the taper stays whole.

I have been training for weeks already. Do I start over?

No. NavRun counts the weeks you have already run, so ten weeks in reads "Week 11 of 12", not "Week 1".

Is the whole-block plan free?

Yes. Seeing the whole build and having your weeks written are free.

What happens to my other races?

They stay in the build as training races, and a bigger one gets an easier week after it.

Can I build toward a backyard ultra or a 24 hour race?

Not yet. A timed race has no distance, and the build needs one to size the weeks.


The weeks are the point

Seeing race day as a number of weeks takes one worry off the table. You know where you are and what this week is for. The rest fills in from the running you do.

How each day inside those weeks gets written is on the training plans page.

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