Run the Hills to Own the Flats

• Running uphill strengthens muscles, improves power and technique, making flat running more efficient and less wasteful.
• Running downhill develops coordination, eccentric strength and neuromuscular endurance, improving running economy.
• Alternating uphill/downhill creates “overcapacity” useful for running better and longer on flat terrain.

When you hear the word “mountain,” the first image that pops into your mind probably isn’t of you running up one. More likely, you picture a cozy shelter, a sunny deck chair, and yourself sprawled out on it. But what if the mountain could be your open-air gym—a place to test your limits and discover a new side of running?

If you think uphill running is all about strength and downhill is just easy coasting, it’s time for a reset. Mountains and hills are unforgiving—but they’re also some of the best teachers. And they’ll make you a better runner on flat terrain, too.

Climbing: an art of balance and power

Running uphill can feel pointless at first—how can you run on an incline that’s tiring even to walk? To make it work, you’ve got to let go of the long, relaxed stride of road running. On hills, short strides rule. Biomechanically, you just can’t move the same way you do on flat ground.

Biomechanics of ascent

Uphill running isn’t just “regular running but slower,” or “running on an inclined plane.” It’s its own thing. First, you lean slightly forward to shift your center of gravity closer to the ground. Your stride shortens naturally, and you land more on your forefoot. Your joints—knees, hips, and ankles—stay more flexed during stance and extend during push-off, engaging muscles like the quads, calves, glutes, and the iliopsoas.

Why? Because gravity is working against you now. Every meter you climb is a fight against the pull of gravity. That means your leg muscles, especially your quads and calves, work harder—and your heart rate climbs too.

How to handle the climb

You’re on a different surface, a different plane—and a different mindset. Here’s how to take it on:

• Keep strides short and quick – Think like a metronome: steady and efficient.

• Use your arms – Swing them with purpose, like rowing. Poles help too, especially at altitude—they take some of the load off your legs.

• Slight forward lean – Helps balance without wasting energy.

• Look ahead – Don’t watch your feet. Scan the trail to read the terrain before you reach it.

Training the ascent

Uphill running is a great substitute—or boost—for interval training. It mimics intervals while also building strength and technique. Try:

• Short hill sprints – Great for explosive strength.

• Long climbs at steady pace – Build endurance and form.

• Strength drills – Lunges, step-ups, and squats target the muscles that power you uphill.

The descent: like a dance

Downhill running is often misunderstood. Since gravity’s working with you, people assume it’s easier. But many trail runners say the downhill sections are the toughest—thanks to the technique and control they demand.

Biomechanics of Descent

Going downhill tempts you to let go, but that can be risky. Your stride opens up, landings shift to the heel, and your joints take a pounding. To stay balanced, you need to do something counterintuitive: lean forward slightly, land on your midfoot, and keep your knees soft to absorb impact.

Every downhill step is basically braking—controlling the momentum pulling you forward. That’s hard on your knees and ankles, which is why downhills can be even more taxing than climbs.

How to Run Downhill

Even for downhill running, there are techniques and tips

• Use a short, agile stride: do not try to strides, but keep a fast, controlled pace.
• Keep your knees slightly flexed-this will help cushion the impact.
• Keep your torso slightly tilted forward and do not brake with your heels, but try to land with the middle part of your foot (midfoot).
• Keep your gaze forward and focused: pay attention to the ground and anticipate movements.
• Upright and relaxed posture: avoid leaning backward.

What does flat running have to do with it?

We promised you that running in the mountains would also help you with flat running. Here then is explained why.

The uphill one:

1. Strengthens muscles: by strengthening quadriceps, calves and glutes with a greater load than flat, it creates a “reserve of strength” that makes it easier and more efficient to run on flat surfaces.
2. It improves the athletic gesture as it naturally pushes for forefoot support and more effective pushing, habits that, transferred to the plane, help you run more efficiently and less energy expending.
3. Increase power: Uphill intervals are one of the best workouts for developing power and explosive strength, qualities that translate into greater speed and a snappier stride on flat terrain.
4. It is good for the heart, as the intensity of uphill running significantly increases cardiac effort, improving aerobic capacity and anaerobic threshold-key parameters for flat performance.

The downhill one:

1. It trains the muscles eccentrically: that is, stretching them while under tension, thus developing specific strength that improves muscle endurance on the floor as well.
2. It improves running economy since it also teaches you to control your body downhill from a proprioceptive point of view, thus refining coordination and efficiency of athletic gesture, qualities you can also exploit in flat running.
3. It increases neuromuscular fatigue resistance, as downhills train the nervous system to better manage fatigue, allowing you to maintain effective technique even when you are tired on flat terrain runs.
4. Strengthens ligaments and tendons: as the controlled stresses of downhill running strengthen connective tissue structures, reducing the risk of injury even in flat running.
5. It increases reaction speed, resulting from the habit of managing the foot downhill as a function of stance; on the road this speed becomes a snappier, faster stride on the flat.

The combination of uphill and downhill training makes you a more complete, physically stronger and technically more efficient runner. If you get a chance to run in the mountains in short, you know you can build up an “overcapacity” that makes running on the flat easier and more sustainable, especially in the final stages of a race, when fatigue then sets in.

Not surprisingly, many of the best road runners regularly include uphill and, when possible, downhill workouts in their training precisely to take advantage of these specific benefits.