Last fall, I joined a group of runners on a demanding but rewarding hut-to-hut run through New Hampshire’s White Mountains. Over four days, we ran more than 30 miles and accumulated nearly 10,000 feet of elevation gain on technical trails full of boulders and undulating ridgelines teasing us with false summits. Our goal each day was to reach a new Appalachian Mountain Club hut, where we enjoyed a hot meal and sleeping bunks. When morning came, we’d hit the trail again.

I’ve been Running for more than a decade, and I’ve finished a handful of half-marathons and shorter races across the West. I’m not fast or competitive. I prefer to take my time on long, rolling trails. But on this unforgettable trip to New Hampshire, I caught the bug for Mountain Running.

At its core, mountain running means running up and down steep terrain in the mountains. Mountain runs can be as short as a 15-minute sprint and as long as a multi-day excursion. Often, it involves summiting a high-altitude peak, but the sport’s most defining characteristics are significant elevation gain (and loss) and a mix of on- and off-trail terrain.

On my White Mountains adventure, I tackled trails alongside mountain running experts Hillary Gerardi and Jr Rodriguez. Gerardi is a professional mountain athlete: Her primary sport is running (both ultramarathons and mountain running), and she also skis and bikes. Rodriguez is a multi-sport athlete with experience in mountain running, rock climbing, skiing, and fly fishing.

If you like trail running and are looking for a bigger challenge, mountain running is a logical next step—and this guide will help you set off on the right foot. The expertise in this guide is based on interviews with Gerardi and Rodriguez as well as my own experiences with mountain running, which includes the New Hampshire trip and a handful of other adventures. Here’s more info on mountain running, how to get started with it, and the essential gear you need.

Mountain Running vs. Trail Running

If trail running is a genre, mountain running is a subgenre. Trail running is pretty simple: going for a run on trails. There are no elevation gain or distance requirements. As trail runners push into higher altitudes and distances, there’s often crossover with mountain running, but the two are technically considered separate racing activities. The biggest differences arise when it comes to terrain, elevation, and distance.

Mountain running is governed by the World Mountain Running Association. The WMRA defines mountain running as taking place on terrain that is mainly off-road and following a route with significant elevation gain. There are also specific definitions for mountain running races. The Valsir World Mountain Running Cup, for example, has several events, including the short uphill race (3 to 8 kilometers in distance with 750 to 1000 meters of elevation gain), the classic mountain race (9 to 21K with 100 to 150 meters of elevation gain per kilometer), and long mountain race (22 to 45K with 80 to 120 meters of elevation gain per kilometer). 

For the average runner, however, mountain running is just as its name suggests: running in the mountains. As Gerardi defines it, mountain running includes running uphill and downhill as high and for as long as a runner wants.

“You’re running up and down mountains,” she says, “whereas you can trail run on the flats and that’s completely legit trail running.”

Mountain Running Pace

Often, mountain running involves a lot of walking. Along a trail, you’ll encounter sections that you can’t run through, like steep, rocky inclines or areas with lots of fallen trees. The goal is just to keep moving and run when possible. And speed isn’t everything—in fact, a slower, more sustainable pace is an essential part of mountain running.

“The slow pace calms your nervous system and your heart rate down,” says Rodriguez, “and it helps you control your breathing so that you can go longer and farther.” 

Where Can You Mountain Run?

You can mountain run anywhere there are mountains—that includes everything from the snow-capped spires of the Sierra Nevada to the forested peaks of the Appalachians.

Don’t live close to any mountains? You can start out on whatever hills you have nearby. As Gerardi says, “The size of the mountain is kind of in the eye of the beholder.” 

How to Train for Mountain Running

If you’re used to road running or flatter trail running, toss out your expectations. Mountain running takes far longer, and because every trail is different and conditions vary widely at higher elevations, it’s often hard to maintain a consistent pace. Always start small and work your way up to longer, more challenging runs.

To start out, Gerardi suggests treating your first mountain run like a speedier variation of hiking. Pick a hiking route, check the average time it takes to complete, and then try to finish the trail a little bit faster than the average hiker. Run when it feels good, but remember that walking is totally acceptable.

“When you start from a basis of running, people are discouraged because they’re constantly comparing their splits from running,” Gerardi says. “But if you compare your speed to hiking, then you’re like, ‘Wow I’m going so much faster.’”

In addition to running outdoors, anything you can do to strengthen your core, hamstrings, quads, glutes, back, and ankles will be helpful for mountain running. (Click on the links to see specific exercises for those areas.) Personally, I’ve found that balancing on one foot on a bosu ball is a great way to strengthen my ankles, while stair climbing, squats, and lunges are great for building leg muscles.

Other sports and activities can be helpful, too: Mountain runners often cross-train by cycling, hiking, skiing, and doing yoga. 

Staying Safe While Mountain Running

The main safety concerns when mountain running include hydrating and fueling properly to sustain your effort. Always pack water and food, and try to drink small sips and eat bites of food as you’re moving.

Another safety concern is safely navigating remote areas. If you’re a beginner, stick to well-worn trails—or even better, trails you’ve already hiked before—before venturing onto rocky scrambles where you could potentially lose your way. Before you head out for a mountain run, study a map of your route, so you know where you’ll be going, and always tell somebody where you’re headed, even if you’re going with a partner. It’s also a smart idea to bring a satellite communication device so you can call for help if you need it.

Beginners should also be mindful of pushing too hard too quickly. If you feel lightheaded, short of breath, nauseous, or your muscles cramp up, you need to stop. Rodriguez rejects the “no pain, no gain” mindset in favor of listening to your body. Ignoring it can lead to injury.

“Your body is always trying to tell you something,” he says.

Essential Mountain Running Gear

When you’re just starting out, use the trail running and hiking pieces you already have and then make adjustments as needed. For example, Gerardi emphasizes having accessible nutrition and hydration, since that will allow you to move faster and stay fueled more easily.

From head to toe, here are a few essential mountain running gear recommendations. They’re based on what Gerardi and Rodriguez use on their runs as well as what I’ve tested out myself.