La Sportiva Nucleo High Review – Ankle support in light package

The La Sportiva Nucleo High boot is rare. It’s a lightweight backpacking and hiking boot with high-cut ankle support. It took me several years to get my hands on this award-winning boot. You see, La Sportivas run narrow. My feet don’t. I was unable to test or wear one of the lightweight hiking boots before 2021. La Sportiva’s new Nucleo High II GTX was released in wide. This review of the La Sportiva Nucleo High focuses on the boot’s support and weight as well as its waterproofing, waterproofing, durability and fit.

Review: La Sportiva Nucleo High II GTX

La Sportiva’s Nucleo High GTX burst onto the scene five years ago as a lightweight, high cut hiking boot with premium (Vibram) outsoles and Gore Tex’s most breathable waterproof membrane (Gore Tex Surround). That won it a few awards, such as REI Co-op Editors’ Choice Award and Outside Magazine’s 2017 Gear of the Year Award.

This review is about the Nucleo High II GTX, the latest edition of this boot. This boot has been used to backpack hundreds of miles. This included many day hikes through Pennsylvania and New Hampshire’s White Mountains. It also included some of Pennsylvania’s most famous backpacking trips like the Loyalsock Trail or Black Forest Trail. Based on my testing, the Nucleo High II GTX may be a good choice for many hikers.

  • Fast-and-light hikers who prefer shoes to boots for foot and ankle support
  • Women and men looking to get better traction on wet rock
  • Hikers and backpackers who need the best waterproofing.
  • Backpackers who want to lose weight but not sacrifice the benefits of their hiking boots

La Sportiva Nucleo High Review

Women’s Nucleo High II GTX
Men’s Nucleo High II GTX


It is difficult to create a hiking boot that is both lightweight and supportive. To reduce weight, you have to cut back on cushioning and support. The Nucleo II is a backpacker and hiker’s best friend because it offers moderate support with a light weight.

The Nucleo offers better ankle support than lightweight hiking boots. A hiking or backpacking boot should have (1) a high collar at the ankle, (2) a stiff ankle collar, (3) a stiff sole and good torsional rigidity. Here’s the Nucleo going 2-for-3:

  • The Nucleo is at minimum an inch taller that most “mid”-cut hiking boots. It has a more substantial ankle collar and heel than the Salomon Ultra Mid, which also ranks on my list of best lightweight hiking boot.
  • Keep in mind that the soft, nubuck-leather provides good but not great ankle support. It’s also lighter than some mid-weight hiking boots.
  • The soles of the Nucleo are stiff at the midfoot, but have good torsional rigidity. This should help prevent rolled ankles.

The Nucleo High II GTX makes my sore feet and ankles feel quite comfortable. I have had no problems hiking or backpacking on Pennsylvania’s more difficult trails (45 miles/9000ft elevation gain).

The Nucleo’s soles are thicker and more durable than many lightweight boots, but lighter than most hiking boots. These outsoles will absorb some of the trail’s pounding and prevent your feet from flexing on uneven terrain. Rubber surrounds and toe bumpers provide protection from rocks, roots and other hazards on the trail.

Nucleos should support your feet and ankles on steep and rocky trails

This boot is lightweight and provides good support. This boot is a good choice for moderate backpacking or moderate-to-hard day hiking.


Sportiva recommends the Nucleo High II GTX to be a lightweight backpacking and hiking boot. It is lightweight for a backpacking boots and lighter than the average hiking boot. It does feel and weigh like a boot but not like a running shoe.

The Nucleo High is not as light as its mid-cut Salomon X Ultra 4. My pair is 6 ounces lighter than my Oboz Bridgers (one the most popular mid-weights) but almost a pound lighter than the Salomon Quest which is the top-rated backpacking boot.

If you can hike fast enough, or far enough, your weight loss should be equal to some energy savings. La Sportivas feel lighter in my Oboz and I can hike faster with them because I alternate between my pairs. However, my pace is fairly consistent regardless of how heavy I am. This can be seen in the app that I use to track my hiking.

This boot is a good choice for backpackers and hikers who don’t want to lose foot and ankle support.


Comfort is subjective. There will be different comfort preferences depending on how you hike, what you do, and where you live. There’s so much to love here.

Women’s La Sportiva Nucleos (Photo Courtesy of La Sportiva / Photographer Aly Nicklas)

I feel great around my feet and ankles with the Nucleo’s soft, Nubuck uppers. The Nucleo is well cushioned for La Sportiva, a brand that tends to run stiffer and has less “feel” than “float”. The Nucleo now comes in both standard and large sizes so more people can hike comfortably in La Sportivas, one of best brands for hikers.

These boots are very comfortable for me. I think my hiking feet would benefit from a bit more arch support. These boots feel great but my feet feel fatigued on longer hikes in Nucleos than in mid-weight hiking shoes. For more arch support, I replaced the boot’s insoles by Superfeet insoles. These are my favorite!


After 400 miles of wear, my pair is still in great shape. My Nubuck leather uppers are in excellent condition as is the rubber rand. My Vibram outsoles are showing normal wear patterns for their mileage.

However, I have experienced a few durability issues. Sportiva’s thin shoe laces were not strong enough to withstand hard hiking. My first backpacking trip with them was 20 miles in and one of my laces broke on an uphill climb. One of my laces snapped while I was walking along the Franconia Ridge Trail in New Hampshire’s White Mountains. This would have ended my trip if I hadn’t brought extra laces.

The ventilated mesh (Nano Cell), which runs between the boot’s outsoles and uppers, is my other wear area. These meshes are supposed to improve breathability. The protective TPU overlay has begun to fall off as a result of rocks hitting the area. My waterproof membrane is also experiencing this problem. It doesn’t seem to work as well after moderate usage.

The boot’s durability is average for a lightweight hiking boot.


The Nucleo High II GTX is also known for its traction. La Sportiva is known for making the best climbing shoes in the world, so their hiking footwear has grippy soles that are especially suitable for rugged terrain.

Vibram Outsoles on La Sportiva Nucleo Highs

La Sportiva sources its outsoles form Vibram, an Italian company that has been producing high-quality outsoles for over 100 years. The Nucleos ride on Vibram’s(r), Nano XS -Trek Compound, a technical rubber that is known for its flexibility and wet traction for a wide range of outdoor activities. This is a huge plus.

The soft, shallow lugs of this outsole are extremely grippy on rocks and other surfaces. My Nucleos had excellent grip on Pennsylvania’s Mid State Trail, and Black Forest Trail. The heel brake is pronounced to provide better downhill traction. This lug pattern has not been as effective in mud where I have taken a few tumbles.

You can expect good traction on wet and hard surfaces as long as the rubber lasts.

the Nucleo’s Vibram soles should have excellent traction on talus, rock, & scree

water resistance

The “GTX” in the Nucleo High II GTX stands for Gore Tex, still the best waterproof-breathable membranes in outdoor gear.

Gore Tex is a thin sheet of Teflon (expanded polytetrafluoroethylene) with 9 billion microscopic pores per square inch. Each pore is approximately 20,000 times smaller that a single droplet of water. These microscopic pores can also be 700 times bigger than a single water vapor molecule. That’s how Gore TEX’s waterproof-breathable membranes keep liquid from seeping in to your feet (“waterproof”) and also release evaporated moisture vapor into the outside air (“breathable”).

the Nucleo High features Gore Tex Surround for reliable and breathable waterproofing

Nucleos have GORETEX Surround, which is the most breathable waterproofing available. GORE TEX Surround channels heat, moisture vapor away form your feet in all directions–even through the sole. Nucleos can help your feet and socks stay dry in more conditions than waterproof hiking or backpacking boots.

My partner performed well on muddy spring backpacking trips. This included a 45-mile loop with over 50 water crossings. However, as the miles added up, I have taken on more moisture. My suspicion is that my Gore Tex membrane may have failed at the point where Nano Cells on my boots’ outsides have worn off. My feet are still dry in most situations.


La Sportivas is a narrow, slightly smaller version of most Italian brands. This brand has been a good fit for those with narrow feet in the past. They have begun offering their top hiking shoes in wider sizes for backpackers and hikers in North America starting in 2021. The Nucleo will now be able to fit more feet.

For sizing and fitting, nothing beats the experience of trying on shoes in person. Here are some general tips for fitting the La Sportiva Nucleo II GTX.

  • For narrow feet, size up to a half size (after converting Euro size to US size).
  • Standard size feet: Size up to 1/2 size, and consider wider sizes for comfort
  • Wide feet: Choose widest and size up to a full size

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