Are you signed up for a trail race of about 40 km or 42 km and looking for a training plan? This distance, sometimes called a ‘Maratrail’, combines the length of a marathon with the challenges of trail running. The fastest runners complete it in about 3 hours, while others may take up to 10 hours, meaning your approach should vary depending on your objective.
Whether you’re participating in the MCC at UTMB Mont-Blanc, the Marathon Race at MaXi-Race, the Mont Blanc Marathon, or another maratrail, you’re in the right place. Here are the principles of a 40 km or 42 km trail running training plan.
RunMotion Coach is a partner of the Mont Blanc Marathon. Here is how many weeks to plan for, what a typical week looks like and which sessions matter most.
The short answer
- Allow 12 to 16 weeks of preparation if you already run regularly.
- The key session is the hike-and-run: a long outing alternating running and walking, building up to 3 hours or more.
- Every week, add hills (short or long), strength work and some downhill running.
- A trail marathon usually takes between 3h and 10h, depending on elevation gain and your level.
Contents
- Understanding the Profile of Your Maratrail
- Fundamentals of the 40 km or 42 km Trail Running Training Plan
- How many weeks do you need to prepare for a 40 km trail race?
- Sample training week for a 40 km trail race
- What time should you aim for on a 42 km trail?
- Trail marathon training plan: frequently asked questions
- Your 40 km or 42 km Trail Running Training Plan
Understanding the Profile of Your Maratrail
In the Alps or other mountainous areas, 40 km trails can have elevations of around 2000m, sometimes more. The higher the elevation gain-to-distance ratio, the more you need to focus on muscular strength in your training. The pace will be slower, and for runners who expect to spend more than 5 hours on the course or for whom strength is a limiting factor, the use of poles should be considered.
For more rolling trails, preparation will be similar to that of a road marathon, albeit with some necessary adaptations.
Preparing for a 40 km trail with 2000 m of elevation gain
With 2000 m of elevation gain over 40 km, you climb an average of 50 m per kilometre, often concentrated in a few long ascents. You will walk part of the climbs: that is normal, and it can be trained. Do hike-and-run sessions in the mountains or on the longest hills near you, and work on power hiking on steep slopes. If your race allows poles, train with them for several weeks before deciding whether to use them. An intensive training weekend 4 to 6 weeks before the race is also a good way to build up elevation.
Fundamentals of the 40 km or 42 km Trail Running Training Plan
A 40 km trail, or maratrail, typically takes between 3 to 10 hours to complete, depending on the course profile. Factors such as endurance, running economy, and muscular strength are crucial.
Hike-and-Run Training
To develop endurance, include hike-and-run sessions of 2 hours or more in your training plan. The purpose of hike-and-run is to alternate between walking and running while maintaining a moderate heart rate (in zones 2 or 3 in terms of intensity). These sessions should ideally be on trails similar to those you’ll encounter on race day.
These outings also provide an opportunity to test your gear, nutrition, and hydration strategies (about 500 ml of water per hour of effort).
Working on Resistance and Muscle Strength
For resistance and muscle strength, incorporate short hill repeats, long hill climbs, and muscle strengthening exercises, including proprioception and exercises specific to trail running. Cycling can also be a beneficial addition.
Examples include:
- Short hill repeats: 12 x 25 seconds with recovery by jogging downhill.
- Long hill climbs: 5 x 6 minutes on hills.
In your training plan, it’s also important to work on downhill running to handle the negative elevation on race day. While races in these formats are rarely won on the descent, being unprepared can lead to significant time loss.
How many weeks do you need to prepare for a 40 km trail race?
If you already run regularly and have done a shorter trail race, allow 12 to 16 weeks. If this is your first trail race, start with a 20 to 30 km event using our 20 km trail training plan: it is the best way to discover elevation, race nutrition and pacing over a long effort.
The preparation falls into three phases: the base phase, to build endurance and strength; the specific phase, with long runs that look more and more like your race; and the taper, the last two weeks, so you arrive fresh.
Sample training week for a 40 km trail race
This example is for a runner training 4 times a week over 14 weeks, for a trail marathon with 1500 to 2500 m of elevation gain. The durations are guidelines: adjust them to your level and recovery.
| Phase | Session 1 | Session 2 | Session 3 | Session 4 |
|---|---|---|---|---|
| Base (weeks 1 to 5) | 50 to 60′ easy run | Short hills: 12×25″, recover on the way down | 30′ of strength work or 1h of cycling | Hilly long run of 1h45 to 2h30 |
| Specific (weeks 6 to 12) | Easy run with 10 downhills of 1′ | Long hills: 5×6′ | 30′ of strength work or 1h of cycling | Hike-and-run of 3h to 4h on terrain similar to your race |
| Taper (weeks 13 and 14) | 40′ easy run | Short reminder: 6×1′ uphill | Rest or easy cycling | 1h30 hike-and-run, then race day |
Every 3 to 4 weeks, reduce the volume slightly to recover well.
What time should you aim for on a 42 km trail?
A trail marathon usually takes between 3h and 10h. To compare two courses, use effort kilometres: every 100 m of elevation gain adds 1 effort-km. A 42 km race with 2500 m of climbing is therefore 67 effort-km, far more than a road marathon. To estimate your finish time and aid station splits, use our Race Strategy tool and prepare your trail race plan.
Trail marathon training plan: frequently asked questions
How long should my long run be before a 40 km trail race?
Build up gradually to one or two hike-and-run sessions of 3h to 4h, 3 to 5 weeks before the race. You don’t need to cover 40 km in training: time on your feet and elevation gain are what count.
How many kilometres a week to prepare for a 40 km trail?
In trail running, think in hours and elevation rather than kilometres. For a regular runner, 4 to 6 hours a week at the peak of the preparation is often enough.
Should I use poles on a 42 km trail race?
They become useful when climbs are long and steep, or if you will be out for more than 5 hours. Train with them before deciding, and check your race rules. Our tips for running with poles.
What should I eat during a 40 km trail race?
Over 4 hours or more, you need to eat and drink regularly from the start. Test your strategy during your hike-and-run sessions, never for the first time on race day. See our guide on nutrition for marathons and trail races.
Your 40 km or 42 km Trail Running Training Plan
Consider these elements and work on these varied aspects for your training plan. An easy way to do this is to download RunMotion Coach, as our algorithms will create your personalized training plan. It will be tailored to your goal, experience, and available training terrains (trails, mountains, hills, etc.), and will evolve based on your feedback.
Your training plan may include sessions like:
- 3-hour hike-and-run.
- Hill repeats: 12 x 25 seconds.
- Long hills: 5 x 6 minutes.
- 10 x 1-minute descents, etc.
In the Premium version, you’ll also have access to strength and conditioning workouts for trail running. Muscle strengthening is an important element in these 40 or 42 km formats. In the weeks leading up to your race, you’ll receive specific advice, especially on nutrition.
The RunMotion Coach app, based in the Alps in Chambéry, supports runners of all levels and from all locations. One of our founders, Guillaume Adam, has excelled in maratrail distances, winning the Marathon Experience at the Maxi-Race and finishing 2nd in the MCC at UTMB® Mont-Blanc.
Happy training with your 40 or 42 km trail running training plan!
