A good trail running season is mostly decided before the first training week. The runners who end the year happy usually made a few clear choices early: one race that matters most, enough weeks to prepare for it, a couple of smaller races that help rather than get in the way, and real breaks between the hard parts.
The short answer: to plan your trail running season, review last year, work out how much time you really have each week, choose one A race, count back the training weeks you need for that distance, then place your B and C races and your recovery around it. Everything else is detail.
Here is how to do each step, with the week counts we use with athletes at Vert.run.
Step 1: Look back before you look ahead
Before you open a race calendar, spend ten minutes on the season you just finished. A few honest answers will shape next year more than any race list:
- Which race or training block felt best, and why?
- Where did things go wrong: an injury, illness, a work crunch, a block that started too late?
- How many weeks did you actually train consistently, and what broke the streak?
- Did you arrive at your main race fresh, or already tired?
If the same problem shows up twice, plan around it this time. If spring is always your busiest period at work, for example, a big race in May is probably fighting your calendar.
Step 2: Work out how much time you really have
Your season has to fit the week you actually live, not the week you would like to have. Write down the hours you can train in a normal week and in a busy one, plus the days that are reliably free for a long run.
For context, the runners in our State of Trail Running report average about five hours of training a week, usually over four or five days. Plenty of runners finish ultras on that. What matters is that the plan matches your number, so you can repeat it week after week.
Step 3: Choose your A race
Your A race is the one race the season is built around. One per season is ideal; two can work if they are far enough apart for a full build and a proper recovery in between, which in practice means at least four months.
When you choose it, check four things:
- The date. Is there enough time to prepare? Step 4 shows how many weeks you need.
- The terrain. Does the course match where you can train? A mountain race is very possible from a flat city, it just needs a more deliberate plan. Our guide to training for hills without mountains covers how.
- The cutoffs. Look at the time limits and the results from previous years. If you are unsure where you would finish, our free Race Time Predictor gives you an estimate for the course.
- The step up. Moving up one distance at a time (trail marathon, then 50K, then 50 miles or 100K) is the most reliable way to keep a season on track.
Step 4: Count back the training weeks
Once the date is set, count backwards to find when training needs to start. These are the ranges from our distance guides, assuming you can already run comfortably three or four times a week. If you are coming back from a break or new to trails, use the top of the range or add a few weeks of easy base first.
| Distance | Typical preparation | Guide |
|---|---|---|
| Trail marathon | 14 to 18 weeks | Trail marathon training plan |
| 50K | About 12 weeks of specific training, 16 to 20 weeks in total if you are newer | 50K training guide |
| 50 miles | About 16 weeks from a 50K-ready base | 50-mile training plan |
| 100K | About 14 to 20 weeks, including a two-week taper | 100K training plan |
| 100 miles | 16 to 24 weeks of focused training | 100-mile training guide |
A quick example: if your A race is a 50K on Saturday, June 5, 2027, and you want 20 weeks, training starts the week of January 18. If that date is already uncomfortably close when you sit down to plan, it’s a sign to choose a later race or a shorter one, not to squeeze the build.
Inside those weeks, the order is always the same: build a base first, then make training more and more like the race, then taper for the last one to three weeks. The distance guides above break each phase down week by week.
Step 5: Place your B and C races
Other races are great for a season, as long as they serve the A race instead of competing with it.
- B races are dress rehearsals. Put them four to eight weeks before the A race, run them seriously, and use them to test pacing, fueling and kit. Give them a few lighter days before and some easy days after.
- C races are for fun, for friends, or as a long run with aid stations. They replace a training session instead of adding to the week, and you run them at a controlled effort.
In the 50K example, a 25 km trail race on April 24 (six weeks out) works well as a B race, and a local half marathon on the trails in March makes a good C race.
A simple test before you register for anything: does this race make my A race better, or does it make me more tired for it? If it’s the second, save it for another season.
Step 6: Plan the recovery, not just the races
Most seasons go wrong in the gaps between hard efforts. Put these on the calendar from the start:
- Lighter weeks inside each training block. Many runners need one every third or fourth week; how often depends on your age, experience and how life is going.
- Easy days after every race. There is no rule that fits everyone. A good habit is to wait until you feel ready to train properly again, then give it one more day.
- Lighter weeks around busy periods you already know about, like a work deadline or family travel.
- A real off-season after your last A race: a few weeks of unstructured running, hiking or rest. Our guide to off-season recovery covers how to use it, and our winter trail running plan picks up from there.
What a full season can look like
Here is one way to lay out a year with two A races, using the example above. In the southern hemisphere, shift everything by about six months.
| When | What |
|---|---|
| November to mid-January | Off-season, then easy running, hiking and strength. Review the season and choose the races. |
| Mid-January to March | Base and build for the 50K. A C race in March as a supported long run. |
| April to May | Race-specific training. B race on April 24. Taper from late May. |
| June 5 | A race: 50K. Then two to three easy weeks. |
| Late June to early October | A 16-week build for an autumn 100K. |
| October 16 | A race: 100K. Then the off-season starts again. |
Not everyone needs two A races. One well-prepared race and a few fun ones is a great season too.
Check in every month
Plans meet real life. Once a month, ask yourself three questions: am I completing most of my planned training, are my long runs getting easier, and am I recovering between hard days? If the answers keep coming back no, change the plan early. Moving to a shorter race or a later date is a normal part of good planning, not a failure.
Common season-planning mistakes
- Signing up for races first and working out the training later.
- Two A races only a few weeks apart.
- Jumping two distances in one season.
- Choosing a race that looks nothing like the terrain you can train on, with no plan to bridge the gap.
- No recovery after the B race, so the A race starts on tired legs.
- No off-season, then wondering why motivation disappears in spring.
What our coaches say
Every year we ask the Vert.run coaches how they would plan a season. Read their answers for 2026 in our coaches’ season advice.
Frequently asked questions
How many races should I do in a trail running season?
Most runners do best with one or two A races, one or two B races, and a few C races if they enjoy them. The number matters less than the spacing: every A race needs a full build before it and real recovery after it.
How far apart should my races be?
Put a B race four to eight weeks before your A race. Two A races should be at least four months apart, so there is time to recover and build again.
When should I start training for a summer ultra?
Count back from race day: about 16 to 20 weeks for a 50K if you are newer to trails, 16 weeks for 50 miles from a 50K-ready base, and 16 to 24 weeks for 100 miles. For a race in early June, that usually means starting in January or February.
How long should my off-season be?
A few weeks of unstructured running, hiking or rest after your last big race is enough for most runners. The aim is to start the next season wanting to train, not needing a break.
How do I choose between two races I like?
Pick the one whose date gives you enough training weeks, whose terrain you can prepare for, and whose cutoffs feel realistic. Keep the other as a B race or save it for next season.
