So far we've talked about physiology, which is the same for all endurance sports. But ultramarathons rarely take place on perfectly flat asphalt. Mountains, mud, roots, rocks and river crossings await us. Welcome to trail running! Different laws apply here, and the preparation of an “asphalt” marathoner needs some serious rework.

5.1. A New “Currency”: Forget About Pace!

The first habit to abandon in the mountains is measuring everything in “minutes per kilometer.” Your main enemy is gravity. A kilometer uphill and a kilometer downhill are two completely different universes in terms of load. Trying to hold a steady pace over rough terrain is a surefire way to “blow up” on the very first climb.

On the trail we have a new “currency”:

Time — how many hours you've spent on your feet.
Elevation gain — how many vertical meters you've climbed. 10 km with 1000 meters of gain is nothing like 10 km through a flat park.
Intensity — your heart rate and perceived effort (RPE). This is the most honest measure of load in the mountains.

Advanced trail runners also track “vertical speed” (VAM), which shows how many meters of elevation gain you make per hour. It's an excellent way to gauge your “mountain” fitness.

5.2. The Art of Moving in the Mountains

Uphill: hiking isn't shameful — it's smart! The trail runner's main rule: choose your mode of movement by efficiency, not by looks. Yes, hiking uphill is normal and often optimal. Even elite athletes switch to hiking on steep climbs.

When to hike and when to run? The core principle of the ultramarathon is to keep your heart rate as even as possible throughout the entire race. Imagine you have a target heart rate (say, 140), and your task is not to exceed it, regardless of the terrain.

Hike if: jogging immediately pushes your heart rate above your target level; your running speed is equal to or lower than a brisk hiking speed; the slope is steep (usually >15%).
Jog if: you can hold your target heart rate and running is noticeably faster than hiking.

A simple rule: if trying to run uphill sends your heart rate soaring while your speed drops to walking speed — switch to hiking! You'll move at the same speed but spend less energy. Remember: in an ultra, the winner isn't the one who runs uphill beautifully, but the one who can still run after 10 hours.

Technique: lean your torso slightly forward and brace your hands on your knees — this creates extra leverage and unloads your leg muscles.
Poles are your “front limbs” and your “four-wheel drive.” They redistribute up to 20–30% of the load from your legs to your shoulder girdle. Important to understand: poles redistribute the load, but they don't reduce the total energy cost of movement — arm fatigue by the end of a long race is very real, so you need to learn to use them in advance too. Master them, and you'll bless the day you bought them. How to choose? Light (carbon), foldable (so they fit in your pack) and the correct length: when you hold the pole, your elbow should be bent at 90 degrees.

Downhill: “falling” at a controlled speed. The descent is not a rest. It's heavy eccentric work for the muscles, which lengthen under load to brake your fall. It's after the descents that your legs feel most “destroyed.”

The main secret: relax! Don't fight the mountain — “dance” with it. Bend your knees slightly, increase your step frequency (cadence), look 2–3 meters ahead rather than at your feet. Your task is not to brake, but to “roll” smoothly downhill.

5.3. Why Does a Runner Need a Bicycle?

“I'm a runner — what do I need a bicycle for?” you may ask. Because it's a secret weapon for building strength endurance without impact load. Long rides, especially uphill at a low pedaling cadence, perfectly imitate the muscular work of running uphill. You “pump up” the right muscles while your joints and ligaments get a break from impact. It's the ideal cross-training tool.

5.4. “Slow” Muscles for Long Running

Think of a chicken: it has white meat (the breast) and red meat (the legs). White meat is glycolytic, “fast” fibers for short, powerful efforts (flapping the wings). Red meat is oxidative, “slow” fibers for prolonged work (walking).

A sprinter is a “chicken breast.” An ultramarathoner is a “chicken leg.” Our task is to use strength and long endurance training to develop precisely the slow, oxidative fibers that run on fat and barely fatigue.

Which exercises should you do? Forget about huge weights in the gym. What we need is strength endurance. That means high-repetition exercises: squats (including single-leg), lunges, step-ups onto a box. Your goal is not to build huge muscles but to make them resistant to fatigue.

5.5. A Home “Vehicle Inspection”

You don't have to go to a laboratory to assess your strength capabilities. Simple tests can tell you a lot about your weak spots:

Single-leg hop. Jump forward as far as you can, landing on the same leg. Compare right and left. A difference of more than 10–15%? That's a reason to think about asymmetry.
Single-leg squat (the “pistol”). Can you perform this exercise without toppling over? It's an excellent test of strength and balance.

Doing such simple tests regularly will help you track progress and spot the “imbalances” that can lead to injury in time. You'll find a whole battery of 49 field tests with reference standards in the strength tests calculator.

In the next chapter we'll put all of this together into a single plan and talk about how to track your progress without digging yourself into the pit of overtraining.