How to Train for Your First Trail Half Marathon (and Actually Enjoy It)
The trail half-marathon sits at a sweet spot in the running world. It’s long enough to test your endurance and mental strength, but short enough that you can still train for it around work, family, and life. Events like the UTA 22km, RollerCoaster 23 km, Buffalo Stampede 20km, Kunanyi Mountain Run 22km, or Ultra Trail Kosciuszko 30km all offer the perfect blend of challenge and satisfaction. You get the hills, the changing terrain, and the sense of adventure that comes from leaving the roads behind.
But training for a trail half isn’t just about running more kilometres on trails. Trails ask for a broader type of fitness — a mix of endurance, strength, control, and the ability to adapt when the surface, slope, or weather suddenly changes. With a few key focuses, you can prepare for all of that without overcomplicating your training or adding endless sessions to your week.
What makes trail halves different
The biggest difference between road and trail running is terrain (hopefully that was clear). On the road, you can settle into a pace and hold it for most of the race. The demand on your body is high, but it’s not very variable. Trails demand a lot more from your body and your training. You’re constantly adjusting — climbing, descending, dodging roots, or navigating rocky sections. Effort, not pace, becomes your guide.
That variability can be confronting at first, especially for runners who are used to structure and predictability. But it’s also what makes trail running rewarding. Once you learn to train for effort instead of pace, you’ll start to feel more comfortable in the unpredictability of uneven terrain. The key is building endurance, developing hill strength (up and down), and improving your ability to move efficiently when the trail throws something unexpected at you.
Building endurance that lasts
Most trail half marathons take between two and four hours for recreational runners. That’s a long time on your feet, and it requires a different approach to long runs. Instead of chasing distance or pace, focus on time and terrain.
Start with incorporating 1-2 trail runs in your week. Keep them easy and more undulating instead of heading straight up the biggest hill you can find. Gradually extend the length of those runs, specifically the long run, towards a maximum of three hours, or that equivalent distance, and aim for the same elevation change per km as you race. with trails, you can do longer time long runs than on the roads more consecutviely becuase of the variying demand and ofter surface
For example, if you are running the Rollercoaster Run 23km, which has 1100m of elevation change, do this:
1100m / 23km = 47.8 m/km
Using this, if you know you are going for a 16km run, then:
16km x 47.8m/km = 765m
The goal is to become comfortable running for prolonged periods at the specific event terrain type. You’ll be training your aerobic system, leg strength, stomach, and mental pacing — the things that will make the biggest difference on race day.
And it’s totally okay to do a higher vert ratio than this; in fact, I would encourage this on some of your long runs. At the same time, there is no need to train over the distance you are racing for your first trail half.
Over the course of 8 weeks, you could follow this kind of progression (assuming you are running roughly 90 minutes on the roads):
8 weeks Out: 12km Trails | ~250m (21m/km)
7 weeks Out: 12km Trails | ~400m (33m/km)
6 weeks Out: 12km Trails | ~575m
5 Weeks Out: 14km Trails | ~670m
4 Weeks Out: 14km Trails | ~ 750m (53m/km)
3 Weeks Out: 16km Trails | ~ 765m
2 Weeks Out: 12-14km Trails | ~ 650m
1 Week Out: 80 min Trails | Undulating
The above assumes that 16km will take ~3 hours in training. We use distance instead of time to help calculate elevation.
If you finish your long runs feeling tired but still steady, that’s a good sign. You don’t need to finish them exhausted. Endurance for the trails is built through patience and repetition, not hero sessions.
The strength behind good trail running
One of the easiest mistakes runners make when training for a trail half is underestimating how much strength matters. Every uphill demands power from your calves, hamstrings, and glutes. Every downhill asks your quads to absorb force with control. Even the smaller stabilising muscles around your hips, knees, and ankles are working harder to keep you balanced.
You don’t need a gym membership or a complicated strength plan to build what you need. Two short sessions a week are enough to make a big difference. Include simple, effective movements like calf raises, split squats, step-ups, single-leg RDLs, Plyometrics, and core stability work such as planks or dead bugs. Focus on controlled movement, not just getting through the reps. Over time, you’ll notice that climbs feel steadier, descents feel more confident, and your legs recover faster between runs.
Strength also plays a major role in injury prevention. Trail running puts a higher demand on your joints and connective tissue because of the uneven surfaces and eccentric loading from downhills. A consistent strength routine improves resilience — not only helping you perform better but also helping you arrive at the start line healthy.
Learn to run by effort, not pace
If you’ve spent most of your running life on the road, this might be the biggest mental shift. On the trail, pace tells you very little. One kilometre might take five minutes on a flat fire road and fifteen minutes on a steep, rocky climb. What matters is how it feels — how sustainable your effort is across the course for the distance remaining.
Practise this by including one run a week on undulating terrain where you pay attention to breathing and perceived effort instead of the watch. Let the uphills slow you down naturally, keep your form relaxed, and use the descents to recover. This teaches your body and mind to manage variable effort and builds the kind of control you’ll need to finish strong.
Hiking can also be a strategic part of trail racing. Hiking with purpose on the steepest sections isn’t a sign of weakness — it’s efficiency. Learning when to switch between running and hiking will help you conserve energy and maintain a steadier rhythm overall. And, this is specific to you. Try and run that extra step in training, but be very deliberate in the event.
Fuel and hydrate early
Trail halves often take longer than road halves, which means fuelling becomes more important. Many runners make the mistake of thinking they can get through without eating or drinking much, only to run out of energy late in the race. The simple rule is to start early, stay consistent, and practise what you plan to do in training (and even go higher on your intake).
As I talked about in this newsletter article on gut training, your stomach can adapt to fuelling if you give it the chance. Start by aiming for 60 grams of carbohydrate per hour, ideally taken in small sips or bites every 15–20 minutes. If you are taking more than two hours, try to get this to 90 g/hour over the course of your training block. Pair this with fluids that aim to replace almost all of what you lose via sweat. The goal isn’t to make yourself sick, but to control the controllables.
Practising this on your long runs is essential. It teaches your gut what to expect, helps you identify which products work best for you, and reduces the risk of stomach issues when it matters most.
You don’t have to live near trails to prepare well
Not everyone has easy access to the mountains, and that’s okay. If you live somewhere flat, you can still build excellent trail fitness. Treadmill incline runs, stair sessions, or even bridges can simulate climbing. For descents, strength work and controlled eccentric training will prepare your legs for downhill impact.
Think of trail training as developing movement quality, not just replicating terrain. You’re training your ability to stay strong, stable, and economical across whatever the trail throws at you. When you finally do get out on real trails — maybe a few weekends before your race — your body will already be prepared to handle it.
Keeping the week simple
Most runners training for a trail half do best with four runs per week. One hill or effort-based session (focus on steadier tempo runs to be more specific), two easy runs, and one long run. Add strength twice per week, and that’s enough. Iif you have come from a higher training load, then adapt accordingly.
Don’t get caught in the trap of thinking more is always better. The runners who improve most are the ones who keep things simple, stay consistent, and recover properly. Small, steady progress beats overtraining every time.
Final thoughts
Training for a trail half-marathon is about balance — enough structure to build fitness, enough flexibility to enjoy the process. You don’t need to run yourself into the ground or spend every weekend in the mountains. You just need a plan that fits your life and builds the qualities trails demand: endurance, strength, and control.
If you do that, race day feels different. The climbs feel manageable, the descents feel controlled, and you can actually take in the views instead of just surviving.
Looking for a one-off conversation about your next event?
I offer Training Consult Calls. It’s a one-off, in-depth session where we map out your race preparation and make sure every week has purpose. You’ll leave with clarity, confidence, and a plan that works.
