Hoka One One launched its new like of mega-fat hiking shoes and boots this spring, and we got an advance peek. The three models—a proper backpacking boot, a flashpacking low-cut shoe, and a mid-cut scrambler—all feature Hoka One One’s signature extra-thick midsole. That extra-thick foam certainly works to lessen the impact on your legs while trail running, but the big question we had was how all that foam would feel under a backpack, or on long days of hiking (rather than a few hours of running.
The burning question—how does it feel to hike on all that foam? In each case, it feels slightly different, as I’ll explain further below.
Overall, I was impressed with the feel of each of the three models—the backpacking Sky Kaha, scrambling-ready Sky Arkali, and flashpacking low-cut Sky Toa. These are legit hiking boots, not some sort of repurposed trail running shoe.
First impression: They hold their own against established boots in the hiking space.
All boots in the Hoka SKY series feature some similar core design elements. Each has a curved outsole design that Hoka calls “Meta-Rocker” geometry. The idea is to help heel strike transition smoothly through toe-off, helping drive the foot forward. This reduces foot stress since the heel and toe are closer to the same height during normal strides.
Underfoot, a marshmallow-soft cushioned midsole provides maximum shock absorption with minimal weight. The midsole thickness and density vary through the length of the foot, which is designed to ensure the best performance throughout the stride.
All of the shoes feature a concave insole Hoka calls an “Active Foot Frame.” This design is somewhat like the bucket seat on a race car. It sinks the heel and forefoot deeply into the midsole cushioning, ensuring the foot stays where it needs to be within the boot for best performance, comfort, and foot-health.
Besides those commonalities, here’s what I thought of each model after initial testing.
The Sky Kaha is designed for backpackers and long distance trekkers. It has a fat 33mm of stack under the heel with 27mm under the forefoot—a 6 mm of offset. Named for the Māori word for strength and support, the Kaha does seem to deliver both. It’s both powerful and ruggedly tough but light and very comfortable. And yes, both waterproof and breathable (thanks to its eVent liner).
I tested the Kahas on sloppy, wet trails in the western Cascade Range during the peak of spring rainy season. Because of the cold, damp, conditions, my pack was loaded with cold-weather gear and lots of extra clothing and food for camp. From the first step, the pillowy cushioning of the midsole was apparent. The boots, remarkably lightweight for a boot this beefy, felt a bit springy underfoot. The Kaha’s Vibram outsole gripped the muddy trails well and handled transitions from mud to rock to snow with ease, providing a firm bite onto all trail surfaces. The boots’ high ankle support felt noticeably protective, but also delivered a comfortable fit from heel to toe. The heel cup cradles the back of the foot and Achilles securely without feeling constrictive, and the toe box allows good mobility without feeling sloppy.
But the big question–how does it feel hiking on all that foam? The short answer is pretty good. Underfoot, the airy midsoles kept me ‘floating’ comfortably on the trail, despite my heavy pack. This provides great comfort, especially on hard, rocky trails, though it took some time to get used to the ‘bounce’ in each stride.
Overall, the Kaha proved to be as supportive and secure as any full-leather backpacking boot I’ve worn in recent years, at less than half the weight of the lightest of those traditional boots. And that’s a pretty impressive accomplishment.
Hikers who tend to get into more dynamic, scrambling terrain will appreciate the Sky Arkali. This active boot has 29mm stack under the heel and 24mm in the forefoot, for a 5mm heel-toe offset. That level of heel-toe differential provides good stability and a natural feeling on downhills while still giving the user added leverage in forward momentum.
During testing in the abrasive volcanic rocks of Washington’s high-desert coulee country, the Arkalis proved adept at adhering to steep rocks while providing outstanding ankle support. Personal story—years ago I shattered my right heel and tore up that ankle in a nasty paragliding crash, and that surgically repaired limb is highly susceptible to sprains and fatigue. Scrambling in the Arkalis, though, nearly eliminated any feelings of discomfort or strain in my weak ‘wheel’. Indeed, since that crash in 2005, my feet never felt more secure and comfortable during aggressive scrambles.
That security came thanks in large part to the big, independently adjusted straps that wrap around the heel and ankle. The lacing system incorporates those adjustable ankle and heel straps for support on uneven and unstable terrain. This is a novel design approach and I think it worked incredibly well.
Since the rocky terrain favored by off-trail scramblers tends to be highly abrasive, HOKA ONE ONE constructed the Arkali’s uppers from a nylon fabric interwoven with Kevlar strands for durability and strength without added weight. That abrasion resistance is enhanced with a rubber rand around the perimeter of the shoe. The Vibram outsole features aggressive multidirectional lugs to bite firmly on jumbled rocks and broken terrain.
And how does it feel scrambling on all that foam? The well-padded Arkalis provide outstanding comfort underfoot, and seemingly removed all risks of foot strain on rough routes. But that thick layer of foam also dampens the ‘feel’ underfoot. That is, the boots don’t readily transmit information about what you are scrambling over. When scrambling up brushy slopes where footing is obscured by vegetation, the only way to know what’s underfoot is by feel. Yet at times, when scrambling in the Arkalis, I wasn’t sure if I was bracing myself on a jagged basalt ledge, or merely a pointy stone on a mud-slick slope.
Hoka’s entry into the fastpacking and day-hiking category, the low-top Sky Toa takes advantage of Hoka’s decade of experience in designing trail running shoes. Indeed, the Toa feels like a Hoka trail runner with a high cuff. The Toa is lightweight, breathable, and comfortable throughout.
The boot cradles the foot, from a snug cupping around the heel to a toe-box with just enough wiggle room to keep your toes happy. The Toas proved ideally suited for fast and light hikes, long day hikes, or even everyday use for the person who spends a lot of time striding around town. Hardcore flashpackers are going to love these for the performance, but they are comfortable enough that they’ve even become my go-to shoe for long dog-walks on our suburban trails.
The Toa features a breathable upper backed by an eVent bootie for waterproofness. The sole drops 4mm, from the 26mm in the heel to 22mm in the forefoot, ever-so-slightly more flat and natural of a feeling than the Kaha and Arkali. While still espousing the maximalist philosophy when it comes to the thickness of the midsole, it’s a little thinner than the others in the line. That doesn’t seem to affect the ‘bounce’ provided by the spongy foam midsoles. Like its big brother, the Kaha, the Toa provided outstanding comfort, with just a bit of springiness underfoot. During initial testing, I felt like my momentum was slightly dampened when striding out on at a fast pace. But as I became more accustomed to the boots, I just the opposite was true. Rather than dampening my efforts, I found that I was actually able to maintain a fast pace for a longer period before I experienced my normal “hiker knee” aches.
The point on the Toa is to drop weight—everything about it has been evaluated from a functional and weight-saving perspective. The use of an abrasion-resistant synthetic upper provides durability without added weight, while the rubberized foam midsole is lightweight but effective. Like its siblings, the Sky Toa boasts a Vibram outsole with aggressive multidirectional lugs – dubbed MegaGrip lugs – to provide solid traction on varied terrain.
The Sky Series hiking boots from Hoka One One look be on track to follow their trail running counterparts in pushing a bold new concept forward in the hiking space. The Sky Series proves that stout, supportive hiking boots can be both lightweight and substantial. They are somehow both stoutly protective and remarkably lightweight. My prediction is this will start a new trend to thicken boots on the trail while thinning them down on the scale.