Mountain running is what you get when you crank up the dial on trail running, but that doesn’t mean there isn’t plenty of kilometres on trail and time spent power hiking. At its core, mountain running is broader than trail running in the fact that it doesn’t require a trail at all, and “mountain” can apply to everything from rolling singletrack to the most demanding, remote peaks. It’s untethered, although it does sometimes require a harness and a rope if you’re moving through glaciated terrain or routes that require rock climbing or rappelling. It’s technical, it’s specialized, and it’s fast and light.

Because of the nature of where mountain running often takes you (high-consequence terrain via cross-country travel), and how you’re getting there (with a fast and light style), it requires durable gear that punches well above its weight. Shaving ounces off your mountain running kit adds up over a 16-hour day on foot, but not having the right gear can end your day. To meet the high demands of mountain running, Arc’teryx gear emphasizes strength-to-weight ratios, lightweight fabrications, reliable waterproofing and wind-resistance, and packability, striking the balance between being prepared and staying light.

Do you need special clothing for mountain running?

Because mountain running requires long, intense efforts in mountain terrain, specialized clothing offers more protection with less overall weight added to your kit. Technical running shorts offer strategically-placed pockets for nutrition and gear, sweat-wicking fabrics, and design details that increase lightness, allow for faster drying times, fight odours, and stay comfortable for very long days out. Similarly, technical tops, shells, and insulated layers provide warmth, weather-resistance, and built-in UV protection with less overall weight than clothing that doesn’t offer the same benefits.

What layers do I need for mountain running?

Because you often encounter a wide range of conditions while in alpine terrain — strong winds, sudden rain, errant snow showers, cloud inversions — carrying a lightweight insulated hoody with a high warmth-to-weight ratio and a lightweight waterproof and wind-resistant shell will keep you covered in most cases. For longer objectives or routes that require water crossings, packing an extra pair of socks can be helpful.