How to train for your first 100-mile race while working full time

I coach busy runners who want to run 100 miles without becoming full-time athletes. They already know how to work hard. What they don't have is a reference point. If you've never run an ultramarathon, you don't know what the training actually requires, so you don't know where to start.

The biggest mistake: no idea where to start

The number one mistake busy professionals make when they train for a 100 on their own is simple: they have no clue where to start.

A lot of people assume that to run 100 miles, you need to train four times as much as you did for a marathon. That's not the case. But if you've never done it, you have nothing to compare it to, so you either overtrain and get hurt, or you get overwhelmed and never sign up.

The truth is the training is very doable on a real working schedule, as long as it's structured.

What a training week actually looks like

Every athlete is different. Your plan depends on where you're starting, what race you're training for, and what your calendar looks like. But the framework is consistent:

• Run five to six days per week.
• Most runs are easy pace. This is where your endurance gets built.
• One to two speed sessions per week.
• Peak volume starts six to nine weeks before the race, depending on the distance.

Peak weekly volume by race distance

Race	Peak weekly running
50K or 50 miles	At least 6 hours/week for 3+ weeks, starting 6 weeks out
100K or 100 miles	At least 9 hours/week for 6 weeks, starting 9 weeks out

Why we train by time, not distance

For ultramarathons, I program by time instead of miles. Trail, elevation and heat all change how fast you move, so an hour on the trail is a more honest measure of the work you're doing than a mileage number. It also makes the plan easier to fit into a calendar. "Run 60 minutes" is something you can schedule. "Run 8 miles" depends on the day.

A real peak week

Here's an actual week from one of my athletes training for 100 miles at a backyard ultra, a race format where you run a 4.17-mile loop every hour until you can't. Effort is on a 1–10 scale (RPE), where 2–3 means you can talk in full sentences the whole time.

Day	Workout	Time
1	Easy run, RPE 2–3. Fully aerobic, conversational the whole way.	1:40
2	Steady-state run, RPE 4–5. 10-minute warm-up, 4 × 20-second strides, then 2 × 25 minutes steady.	1:20
3	Easy run, RPE 2–3.	1:20
4	Easy run with pickups. 10 minutes easy, then 6 × 30-second pickups.	0:50
5	6-hour backyard simulation on trail, RPE 2–3. A 4.16-mile loop, run like race day.	6:00
6	Easy run, RPE 2–3.	0:50
7	Rest and recover.	—
Total	About 65 miles	About 12 hours

Notice the pattern: almost everything is easy, there's one quality session plus some short pickups, and one big day on the weekend that rehearses the race itself. Most of these runs fit before the workday starts.

Long training runs peak around 40 miles, and your longest effort before a 100 is usually a 50-mile race as a tune-up.

How to fit training around travel, meetings and family

Having a dialed-in schedule is the most important thing. Most of my athletes run in the morning, and there's a reason for it:

• They start the day with a win.
• They're done in time to help out with the family before work.
• After work, they can just be with their family, with no training left to make up.

When training is the first thing on the calendar, the rest of the day can't push it out.

How long it takes to go from a marathon to 100 miles

Realistically, about a year: 12 to 18 months from marathon to a 100-mile finish. It depends on the athlete and their goals, but trying to shortcut it is how people end up injured or out of a race.

The way to get there is one step at a time. This is the progression I use:

1. Half marathon
2. Marathon
3. 50K
4. 50 miles
5. 100K
6. 100 miles

Why accountability matters more than motivation

One athlete I work with, Cole, runs a fitness coaching company and advises businesses on how to scale. He's an extremely motivated and disciplined guy. He came to me because he needed a dialed-in program to build up to running 100 miles.

Even Cole admitted that after a long day of work, it's easy to miss a workout if nobody is holding you accountable. That's true for almost every high performer I coach. Discipline gets you started. Structure and accountability are what get you through month nine.

Cole also travels a lot, so the plan couldn't be rigid. We stayed flexible and adapted his training week to week around his schedule, and we knocked it out. He finished his 100 miles in 29 hours.

What your first 100 will teach you

My first 100-miler taught me that I'm capable of way more than I think. That's the thing I want every athlete I coach to leave with.

We put limits on ourselves that just aren't true. A 100-mile race breaks those, and that carries over into your family, your business and everything else.

Your first step this week

Look at the progression above and decide what the next-longest distance is for you. Then sign up for it. Don't wait until you have it all figured out. Pick the race, put it on the calendar, and work out the rest later.

Common questions