Training for an Ultramarathon (50K to 100M)

Start with the time you have

Ultra fitness comes from the total running you carry week after week, not from any one run. So the first job is a weekly load you can repeat for months. A recreational runner who consistently hits the plan can be ready for an ultra on 8 to 12 hours of training a week, all in, cross-training included.

Build in small steps, with an easier week after every two or three weeks of building. No percentage is a tested safe limit, so size each step to how you absorbed the last one (see the guide on training load and recovery).

More time helps only if you can absorb it, so a week you can repeat beats a bigger one you cannot. Count cross-training in your hours. An hour of low-impact aerobic work is real ultra training even though it is not running.

If this is your first ultra, you do not need a bigger plan, you need a safer one. Ask of every training choice what buys the most with the least risk of not being able to run tomorrow.

A week of ultra training

Most good ultra weeks share the same shape. Runsense puts each piece on the days that suit your week.

• Easy runs, most of the week. Slow enough to talk, with strides after two or three of them.
• One hard session. Hills or short fast intervals early in the build, threshold work (about one-hour effort) as the race gets closer. Keep easy days between it and any other hard day, the long days included.
• A long run, or two long days in a row, covered in the next sections.
• One cross-training session of 60 to 120 minutes. Its job is aerobic work without more impact on your feet and legs, so use anything that lifts your heart rate into zone 2, even low zone 2, without pounding your lower body: uphill hiking on a treadmill, a bike, rowing, a ski-erg or cross-country skiing, an elliptical. It suits a body that breaks down under running volume, because the aerobic benefit comes with fewer injuries and consistency is the backbone of a plan.
• Two short strength sessions.
• A day off.

The one hard session

An ultra is run far below your threshold, so why spend a day a week above it? Because your ceiling sets what the race costs. The higher your top end, the smaller a share of it a 100-mile effort takes, and the easier it is to stay comfortable for hours. Long easy running builds the base. One hard session a week keeps the top end from shrinking.

Hard sessions come in a few kinds, and each gives the body a different stimulus. Rotate through them across a build instead of repeating one.

• Threshold: a hard effort you could hold for about an hour, run in long reps. The stimulus is time right at the edge of what you can sustain, and the response is that the edge moves up, so the same pace feels easier and lasts longer. See the guide on tempo and threshold runs.
• Short fast intervals: reps of 1 to 4 minutes at a hard effort, around 5K effort, with easy jogging between. The stimulus is your heart and lungs working near their maximum, and what counts is the total time up there, about 10 to 20 minutes. The response is a higher ceiling, which gives threshold work more room to grow. See the guide on interval workouts.
• Hill power: hard climbs of 30 seconds to 2 minutes, with a walk or jog back down. The stimulus is high muscle force with little pounding, because climbing loads the legs the way fast flat running does without the impact. The response is stronger legs that climb with less effort, which an ultra with real vert asks for. See the guide on hill repeats.

Long runs: hours, not miles

Nobody needs to run the race distance in training, and you should not try. Measure your longest run in hours, and keep most of them, though not always all, at three hours or less. Most of what a run does for your aerobic system comes in roughly its first two hours. After that the gains shift to fueling logistics and muscle breakdown, mostly from eccentric loading (muscles lengthening under load, as they do on descents), and a run past about three hours is hard to recover from, costing you training in the days after it. This holds for every race from the 5K to 100 miles, and longer long runs mostly make you slower.

Fitness comes from weekly volume, never from one big run: easy running spread across many runs, built in small steps and carried for months. It is the total volume carried over long periods, and not the longest run or the two or three biggest, that builds the durability an ultra asks for, and most of a build goes to becoming a good runner. The guide on the long run covers building one.

A few long runs past three hours have a different job: rehearsing pace, food and terrain, in the race's shoes on the race's kind of ground. Only a runner with a strong running foundation does them, and each is sized to the week you run now, not to the longest run you once did. Two long days in a row are more than fine, they are good, when each stays within the three-hour limit: a three-hour run followed by a run of two to two and a half hours practices running and eating on tired legs. See the guide on back-to-back long runs.

Train on the terrain you will race on

An ultra on trails is four sports: climbing, running flat, descending and walking, and all four need training.

So rehearse the race. By the last block, your long runs should climb and descend about as much per mile as the race does, on footing that is as technical. Where you cannot reach hills, an uphill treadmill is the substitute, and an occasional flat long run is a fair compromise. Put descents in your long runs on purpose, because they are hard on the quads (downhill running). Measure these runs by time, not distance. The guide on terrain and conditions covers steep climbs, poles, heat and altitude.

Preview the hardest part of the course. Every race has a crux, and if you cannot run the whole course, run that, in your last big block.

Strength: a little, all year

Strength is the one extra worth making room for, and it is added work, so take a little running out to make room. Any added stress needs a counterbalancing cut in total load, so do not lift on top of unchanged running.

The simple version is Ultra Legs, a 10-minute routine. A runner who wants to lift heavier does it early in the season, while running volume is lowest, because heavy lifting is hard to recover from. See also strength training for runners.

Practice the race food

Fueling is trained like running. Use the product(s) you will race with, on the schedule you will race on, on every long run, and eat the race-day breakfast at the race-day time. Start with the hourly amount of carbohydrate your stomach accepts, aim first for a good experience, then raise the amount. See the guide on carbohydrate during exercise.

The stomach is why this matters. In a 2009 survey at two 161 km races, nausea or vomiting was the reason non-finishers gave most often for dropping out¹. The guides on training your gut and hydration and electrolytes cover the practice.

The taper and race week

Taper for two weeks: cut weekly volume by roughly 40 to 60 percent, in steps, and keep some intensity. If another race sits close, shorten the taper in proportion. See the guide on tapering.

In the last weeks, change nothing dramatic in daily life, food or sleep. Schedule race week hour by hour (shakeout, bib, half an hour at the expo, lunch), because an hour at the expo can turn into five hours of socializing.

Race day: pacing and hard decisions

Start slower than feels right. A simple early check is that you can talk comfortably on the first long climb. Ignore what other runners are doing far from the finish, check whether you have peed in the last couple of hours and what color it was, and in general pace yourself by effort feel rather than by heart rate. Decide your crew and gear before you arrive (see crewing and pacing and foot care and blisters). For a hot race, add heat practice (passive heat training) and incorporate cooling into your race, such as an ice bandana or keeping your head wet.

Settle the hard decisions before the race. People are bad at forecasting how they will feel, and worse at it the longer the task: a runner at mile 70 of a 100-miler stretches today's feeling over the next 30 miles, and often regrets dropping out ten minutes after feeling better. Write a list of what could go wrong in a 100-miler (what if I get nauseous, lose the ability to eat solid foods, get the worst blisters of my life) and decide what you will do about each, so every one already has a plan. Before the race, ask yourself two questions: what keeps you mentally strong if something goes wrong, and are you willing to use every minute the race gives you to fix it and stay in.

When it does go wrong, give yourself time and an easier effort before you decide, because conditions and symptoms can change, especially if you slow down and take care of yourself. The easy decisions to drop are a real injury, heart or breathing trouble, or sudden vision loss, and if a medical professional at the race, not a volunteer or your crew, tells you to withdraw, do it.

After the race

Recovery takes much longer than the race did. After a 50K, Ferdinandson plans on 3 days to 2 weeks before significant training, by how hard it was. After 50 to 100 miles, Runsense follows David Roche: he gives the runners he coaches about one rest day per 10 miles raced, then easy running with hill strides within a week, flat strides a few days later and a short fast session within the first two weeks, while total training stays low. If you do not feel up to that, take the longer recovery Ferdinandson and Koop use: 2 to 3 weeks after 50 miles to 100K and 3 to 6 weeks after a 100-miler before significant training. Soreness goes away first, but the deeper tiredness stays longer, and hard training before it is gone sets you back.

Watch for the trap at a week to ten days. Soreness is gone, blisters have healed, you feel fresh, but a 90-minute to two-hour run shows the deeper fatigue still there. Build back in steps: strides first (5 x 20 seconds), then a tempo, then steady running, then a three-hour run.

The mind needs a break too. Going race to race breeds burnout, and a random adventure, such as a long bike ride over a pass, rests the head and keeps the fitness.