La Sportiva Nucleo High II GTX Review

La Sportiva began as a climbing company, but their expertise in technical gear has translated well to hiking footwear. The Nucleo High II GTX is one of their more capable and well-rounded lightweight hiking boots, and after testing both the men’s and women’s versions on several hikes and backpacking trips in British Columbia and Alberta, we’ve come away impressed with the comfort and trustworthiness on a range of terrain. This isn't the stiffest or most protective boot you can find, but it’s a well-rounded choice for hikers who value nimbleness and light weight. Below, we outline our experiences with the Nucleo High II GTX. To see how it stacks up to the competition, check out our articles on the best hiking boots and the best women's hiking boots.

Editor's note: We updated this article on January 28, 2026, to incorporate our experience with the women's Nucleo High II GTX, as we've now tested both the men's and women's versions. We also ensured all information was up to date at the time of publication and updated the competition section at the end of the review to compare the Nucleo to our other current favorite hiking boots.
 

Table of Contents

• Comfort
• Weight
• Traction
• Stability and Support
• Waterproofing and Breathability
• Build Quality and Durability
• Fit and Sizing
• What We Like/What We Don't
• Comparison Table
• The Competition

Performance

Comfort

La Sportiva footwear generally runs narrow, and the Nucleo High II GTX follows suit. That said, it’s still a very comfortable boot. The leather upper is soft, easy to snug down, and conforms nicely to the foot over time. Padded mesh wraps the ankle, and the gussetted tongue provides a sock-like fit. The collar is more flexible than it appears, allowing a natural gait when climbing or ascending steep slopes. The midsole and insole are also well-padded and offered ample support on long backpacking trips on Vancouver Island's Juan de Fuca Trail and Alberta’s Northover Ridge Loop. The low weight and cushioned midsole give the Nucleo a springy feel, providing decent energy return to help prevent foot fatigue. In fact, we weren’t in a rush to remove these boots after our backpacking trips, which is a testament to their comfort. 
 

Weight

On our scales, the men’s Nucleo High II (size 11) weighed 2 pounds 7.8 ounces, and the women’s (size 8.5) weighed 2 pounds 1.7 ounces. La Sportiva has claimed average weights for the men’s and women’s versions lower than the weights we recorded (2 lb. 1.6 oz. and 1 lb. 10.9 oz., respectively). This lands the boot on the heavy end of lightweight hikers, but on the lightweight end of all-around hikers. For reference, Salomon’s X Ultra 5 GTX weighs, on average, 2 pounds for the men’s and 1 pound 12 ounces for the women’s. Burlier boots like the Lowa Renegade Evo, however, weigh 2 pounds 9.6 ounces and 2 pounds 2.2 ounces for the men’s and women’s models. We think the Nucleo hits a nice middle ground in terms of weight: It feels light and nimble underfoot, even after full days of hiking with a pack on technical terrain. It can hold its own on everything from easy day hikes to lightweight backpacking trips.
 

Traction

Given La Sportiva’s climbing roots, it comes as little surprise that the Nucleo High II GTX scores high marks in the traction department. The boot is equipped with a grippy Vibram outsole and aggressive lug pattern. In testing, the outsole is trustworthy over a variety of terrain, including established trails, sand, mud, slick roots, and even a late-season dusting of snow. We also trusted these boots on a technical ridge scramble consisting of loose rock and dirt. We did experience some unexpected slippage on wet rocks, but in fairness, most outsoles would struggle to grip on similar terrain. Overall, the Nucleo High’s outsole design is very trustworthy and versatile.
 

Stability and Support

Lightweight hiking boots often lack stability and support compared to burlier designs, and the Nucleo High II GTX is no exception. The boot has a notably high cut that provides more ankle coverage than standard mid-height models. However, because the collar is soft and flexible, it offers minimal support and structure. Our opinions here are mixed. Our female tester, Sasha, liked the collar's flexibility, which allowed nimbleness on tricky terrain while still providing enough support to avoid ankle rolls (it’s worth noting that she was carrying a 40 lb. backpack while testing). Our male tester, Brian, found the collar too flexible and would prefer a stiffer boot when hauling a heavy backpacking pack over long distances. He also felt like his ankle was more vulnerable to rock strikes and jagged roots because of the supple materials. In the end, it comes down to preference: If you want a flexible boot that retains nimbleness and you feel confident in your ankle stability, the Nucleo is a great choice. But if your goal is to carry heavy loads over long distances, or if you need extra support for weaker ankles, the Nucleo might not be stiff enough.
 

Protection

Along with support and stability, protection is limited with the lightweight Nucleo High II GTX. On the bright side, the rubber toe cap is robust, and the stiff, reinforced heel does a good job of taking the sting out of harsh impacts. As touched on above, the upper portion of the boot around the ankle also uses thick padding, and the mesh-like rubber siding (designed to increase breathability) adds extra rubber along the lower side of the boot for extra buffering. That said, La Sportiva left the sides of the toe box exposed, which often resulted in feeling jagged rocks and roots poking into our forefeet whenever we misjudged our foot placement. In the end, the Nucleo provides better coverage than many lightweight competitors, but it still isn’t as robust as a burlier hiking boot. 
 

Waterproofing and Breathability

The Nucleo High II is equipped with Gore-Tex waterproofing, which proved reliable when hiking through wet foliage, crossing streams, and hiking through rainstorms. The tall collar and gussetted tongue also help seal out moisture at the top of the boot, making it a great choice for hiking around lakes and along the Pacific coast. And while waterproof boots generally lack in breathability due to the waterproof membrane, the Nucleo is surprisingly breathable. The mesh along the outside of the boot allows heat to escape around the foot, which prevents our feet from getting too sweaty when working hard on exposed sections of trail. That said, like all waterproof designs, the Nucleo takes a while to dry out once submerged, which happened a few times when rogue waves lapped up over the collar. If this is a major concern for you, we’d recommend opting for a non-waterproof boot or shoe (for more on the topic, see our article: Do You Need Waterproof Hiking Shoes?).
 

Build Quality and Durability

From our experience, La Sportiva footwear has always been well-made, and the Nucleo High II GTX is as well. All of the materials are high quality, from the hardwearing nubuck leather upper to the premium waterproof membrane, tough rubber toe cap, and capable outsoles. We should also note that we haven’t gone easy on the boots: They’ve thrashed through tidepools, been engulfed by thick mud, and pounded out around 40 miles of rocky terrain in the Canadian Rockies under the weight of a full pack. Despite the abuse, the boots are holding up incredibly well, with cosmetic dings on the midsole as the only signs of wear. However, it’s worth noting that several other users have reported poor durability with the Nucleo, specifically in the laces and upper. We haven’t experienced any issues yet, but we’ll report back if that changes.
 

Fit and Sizing

As we mentioned above, the Nucleo High II GTX runs narrow, particularly at the forefoot. Both our male and female testers assumed the boot would fit too tightly out of the box, but found that the leather upper stretched and conformed to their feet after some use. A wide version is available for folks with high-volume feet or sensitive bunions, but the regular version should fit most users with some time. The rest of the boot fits great: The heel pocket is snug but not restrictive, there’s good arch support, and the lacing system is effective at locking the foot in place. It’s worth noting that there are no locking eyelets, which required us to get creative with our lacing strategy to achieve our desired fit, but security hasn’t been an issue.
 

Sustainability

Sustainability is at the forefront of outdoor gear innovation today, and many brands have begun incorporating eco-friendly practices into their production to stay competitive. In this case, the La Sportiva Nucleo High II GTX features laces made from 100% recycled polyester, and the insole uses 5% recycled rubber with 15% of the foam taken from production waste. The waterproof membrane is also free of PFAS and other forever chemicals, which have been deemed harmful to the environment and consumers. We do hope to see a greater use of recycled materials in future iterations of the boot, as well as a Bluesign certification, but the measures taken so far are a good reflection of where the industry is headed.
 

Other Versions of the La Sportiva Nucleo High II GTX

We tested both the men’s and women’s Nucleo High II GTX for this review, and aside from color options, the two are identical. There aren’t many variations of this design available. The only other boots in the Nucleo line are wide versions of both the men’s and women’s boots. The wide versions have a broader metatarsal circumference and a taller forefoot height, which accommodates higher-volume feet, and are priced the same as the regular fit.
 

What We Like

• Have a lightweight, springy feel, especially given the high cut and well-padded build.
• Gore-Tex waterproof membrane provides reliable waterproofing and better breathability than most competitors.
• Comfortable right out of the box and doesn’t require much of a break-in period.
• Has proven durable and well-built, though some users have experienced durability issues in the upper and laces.
• Grippy outsole provides trustworthy traction over a variety of terrain.

What We Don’t

• Lightweight build compromises on all-out protection and stability; some users may want a burlier boot for carrying a full load over long distances.
• Pricey for a lightweight hiking boot.
• Narrow fit, especially at the forefoot (La Sportiva does offer dedicated wide sizes).
   

Comparison Table

The Competition

The Nucleo High II GTX is a great lightweight hiking boot, but it’s not the only La Sportiva boot to consider. The TX Hike Mid GTX is another high-performing boot from the brand, but it differs from the Nucleo in a few ways, most notably in fit and traction. The TX Hike has a wider forefoot and a shorter collar, which gives it great comfort out of the box. The outsole is also grippier than the Nucleo’s despite having shallower lugs (it shares the same grippy rubber as the brand’s venerable approach shoe series). It still doesn’t offer the stability and protection of burlier hikers, but it's a great lightweight, trustworthy hiking boot at a slightly lower price. If you want to keep costs even lower, Salomon’s X Ultra 5 Mid GTX is a great option. Like the TX Hike, the X Ultra 5 doesn’t have the stiffest build, but it feels lightweight underfoot, has a durable leather-and-synthetic design, and offers reliable traction. We also like the beefy rubber toe bumper on the X Ultra 5, which did a great job at protecting our toes on the trail. That said, the Nucleo beats both options for underfoot cushioning and energy return, helping prevent foot fatigue on long hikes.
 

If you’re looking for something even lighter weight for fast-and-light missions, it’s worth considering Scarpa’s Rush 2 Pro Mid GTX, which is among the lightest boots you can find. The boot is reminiscent of a running shoe, and we found it very nimble and confidence-inspiring over technical terrain. The midsole is also very springy, and the outsole absorbed impact well on hardpack trails. That said, the low collar and flexible build won’t offer much support for those with weak ankles or for heavyweight backpacking treks. For that, we turn to Lowa’s beefy Renegade Evo GTX Mid, which features a tall, sturdy collar, thick outsole, a rubber toe bumper, and a durable leather construction. There’s no denying that the Renegade is a lot of boot, but it’s a great choice for those who need the extra support. It doesn’t come cheap, but the premium materials are sure to hold up to multiple seasons of rough use. In our opinion, however, the Nucleo High II strikes a nice middle ground between ultralight hiker and stiff boot, making it a versatile choice for those who dabble in both technical day missions and long-distance hiking.
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