An ultra-trail is won or lost months before the start line. Not in one heroic week, but in how the weeks follow each other: how fast the training rises, when it eases off, and what it focuses on as race day gets closer. This guide walks through a season the way most coaches build one, from the first easy weeks to the taper, with the reasoning behind each step so you can adapt it to your own race and your own life.
In short. Work back from race day. Build a broad aerobic base first, then make the training look more and more like the race. Raise the load in small steps, ease off every third or fourth week, and cut the volume by about half over the last two to three weeks while keeping some intensity.
Start from race day and work backwards
Put the race on the calendar first, then count back. For a 100 km race or longer, most athletes who already run regularly need about 24 to 32 weeks: long enough to build volume safely, short enough to stay focused. A shorter ultra (50 to 80 km) can be prepared in 16 to 24 weeks from a solid running base.
If you have more than one race, decide which one matters most. That is your A race: the season peaks for it. Other races become B races (you rest a little before them) or C races (you run them as hard training days). Trying to peak for three races in a season usually means peaking for none.
The phases of a season
A season is usually split into phases, each a few weeks long, each with one main job. The names vary from coach to coach; these are the common ones.
| Phase | Typical length | Main job |
|---|---|---|
| Preparation | 2 to 4 weeks | Get back into regular training after a break; strength and mobility habits. |
| Base | 8 to 12 weeks, in blocks | Aerobic engine: lots of easy running and hiking, gradually more hours, regular strength work. |
| Build | 6 to 8 weeks, in blocks | Make the training race-like: long days with climbing and descending, back-to-back runs, some threshold work. |
| Peak | 2 to 3 weeks | The most specific training: race terrain, race gear, race food, race pace on the climbs. |
| Taper | 2 to 3 weeks | Less volume, keep a little intensity: arrive fresh, not detrained. |
| Transition | 1 to 3 weeks | Recover after the race: easy movement, no plan. |
Base and Build are often split into blocks of three or four weeks (Base 1, Base 2, Base 3, Build 1, Build 2), each block a little bigger than the last.
How fast to raise the hours
Volume in trail running is better counted in hours than in kilometres: an hour on a steep trail and an hour on the road cost about the same, while their distances are very different. Elevation gain is the second number to watch.
Raise the weekly hours in small steps, block by block, rather than week by week in a straight line. A common pattern is three weeks rising, then one easier week at about 60 to 70 % of the block's biggest week. For athletes over 40, or anyone coming back from injury, two weeks up and one easy works well too.
How high to go depends on your history more than on the race. A useful reference: the biggest weeks of the season are often around 1.5 to 2 times what you can comfortably sustain at the start of Base. Someone starting at 6 hours a week might peak at 10 to 12; someone starting at 10 might peak at 15 to 18.
Why every fourth week is easier
Training doesn't make you fitter on the day you do it. It makes you tired, and you get fitter while you recover. A lighter week lets the fitness from the block land, lets small aches settle before they become injuries, and gives you a moment to check how things are going. The easy week isn't a week off: keep the frequency, shorten the sessions, drop the hardest one.
If you feel great at the end of a block, take the easy week anyway. Its benefit shows up in the next block, not in how you feel that week.
Mostly easy, a little hard
Well-trained endurance athletes tend to spend most of their training time at low intensity: roughly 75 to 85 % of sessions easy, the rest moderate or hard. For an ultra, where the race itself is mostly easy-to-steady effort for many hours, that balance matters even more. Easy means you could hold a conversation, including on the climbs, which usually means hiking them.
The harder sessions change with the phases. In Base, short hill sprints and strides keep you sharp without much fatigue. In Build, longer climbs at threshold effort (around the effort you could hold for an hour) and tempo sections inside long runs. In Peak, efforts at the pace you expect to hold on the race's climbs.
Make the training look like the race
As race day gets closer, the training should look more and more like the race itself. For an ultra-trail, that means:
- Time on feet. Long days of 4 to 6 hours in Build and Peak, sometimes as two long days back to back (for example 4 hours on Saturday, 2 to 3 hours on Sunday) to train running on tired legs without one huge session.
- Climbing and descending. The race's elevation per kilometre tells you what to train. Descending is where legs get damaged; practise it regularly so the muscles adapt.
- Hiking. On steep climbs most runners hike in the race, so train hiking with purpose, poles included if you'll use them.
- Food and drink. Every long run is a chance to practise eating: the same products, the same timing as on race day.
- Gear and night. Run in your race shoes and pack, and do at least one long session in the dark if the race goes through the night.
The taper: the last two to three weeks
Research on tapering in endurance sports points the same way: cut the volume by roughly 40 to 60 % over about two weeks, keep some intensity, and keep running almost as often as before. Cutting the intensity too, or stopping altogether, tends to leave athletes flat on race day.
In practice: the last long run about three weeks out, the volume down progressively, a few short race-pace efforts in the last week, and plenty of sleep. Feeling restless or a little heavy during a taper is normal.
After the race
A long ultra takes weeks to recover from, even when your legs feel fine after a few days. Give yourself one to three weeks of easy movement with no plan before the next season starts. That is the Transition phase, and skipping it is one of the most common ways a good season turns into an injury.
When life gets in the way
No season goes exactly to plan. A rule of thumb: missed a few days, carry on with the plan as written; missed a week or more, repeat the last week you did well rather than jumping back in where the plan says you should be. If you're ill, don't train through it; once you're better, restart easy and build back over a few days.
Plan it in MyTrainingDesk
MyTrainingDesk builds your season from your race dates: the phases, the target hours for every week and the mix of easy and hard. When you ask its coach to plan a week, it plans to those targets and tells you when it lowered one because of your recovery.
Sources
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance, 2010; 5(3): 276–291.
- Bosquet L, Montpetit J, Arvisais D, Mujika I. Effects of tapering on performance: a meta-analysis. Medicine & Science in Sports & Exercise, 2007; 39(8): 1358–1365.