We spent 8.5 hours reading reviews from experts and users. In summary, this is what runners think:

7 reasons to buy

  • The Fresh Foam Hierro Boa is comfortable, many runners claimed. 
  • Some consumers said that the traction is excellent. 
  • A couple of buyers testified that the shoe offers good support. 
  • Many purchasers appreciated the shoe’s good cushioning. 
  • A few users mentioned that it is also comfortable for winter runs. 
  • It can be worn without socks, according to a tester.
  • One consumer loved that this shoe is easy to clean. 

3 reasons not to buy

  • The ankle collar was tight making it hard to get on, some users reported. 
  • One runner said that the outsole lugs cause pain and discomfort while running. 
  • The Boa laces can’t get tight enough if you have a small foot, said a buyer. 

Bottom line

The New Balance Fresh Foam Hierro Boa is a neutral running shoe that works best for runners who do not overpronate. It is made out of high-quality materials that enhance durability and comfort even on uneven surfaces. This trail running shoe offers aggressive traction, responsive cushioning, and breathable upper, which are designed to provide an efficient and comfortable running experience. 


Base model: New Balance Fresh Foam Hierro
Terrain: Trail
Arch support: Neutral
Weight: Men: 11.4oz
Heel to toe drop: Men: 8mm
Pronation: Neutral Pronation
Arch type: High arch
Use: Jogging
Material: Mesh upper, Vibram sole
Features: Breathable | Cushioned | Comfortable
Strike Pattern: Midfoot strike
Distance: Daily running | Long distance | Marathon
Technology: Fresh Foam, Vibram
Brand: New Balance
Type: Heavy | Big guy | Low drop
Width: Men: Normal, Wide | Women: Normal, Wide
Price: $160
Colorways: Blue, Multi, Yellow
Small True to size Large
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Expert Reviews

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79 / 100 based on 2 expert reviews

  • 86 / 100 | Timothy Ashford

    New Balance Fresh Foam Hierro Boa: Are these as tough as iron?

    More photos

    With an integrated sock, state of the art lacing system, and top-shelf outsole, the New Balance Fresh Foam Hierro Boa should be a tough performer. Hierro means “iron” in Spanish.

    Are these as tough as iron? Let’s take a look.


    The basics

    Size and weight: Normally, I wear a US 11. This shoe runs pretty true to size. It may be just a bit on the smaller size than usual, so if you are on the border, go ½ size larger. I weighed these in at about 13.1 oz per shoe, for my size.

    Visual: No doubt about it, these shoes look clunky. The thick, brightly colored sole against the darker top, add to the oversized look. The distance from the outside of the outsole to the top of the sock liner is just shy of 6”.



    The lack of laces, being replaced by three “straps” across the top of the shoe, along with the Boa dials on the side of the shoe, add to the chunkier look of the shoe. The colors are not the worst, but unless they are the colors of your alma mater, you may be indifferent to them.

    One of the cool design elements of this shoe is on the outsole. If you look at the red over the black on the outsole, it forms an arrow facing forward.



    Stack and drop: The NB Fresh Foam Hierro has an advertised 8mm of drop. The stack is 30mm at the heel and 22mm at the toe.




    Uppers: The uppers are constructed of a reinforced mesh. The base fabric is a woven breathable material and is infused and overlayed with reinforced multidirectional mesh.

    There are no seams over on the front portion of the shoe. And, the only seams on the back portion of the shoe are those that reinforce the lacing system (more on that in a minute).

    The toe has a flexible rubber cap that creates a reinforced Toe Protect cap.



    Insole: New Balance uses a non-specific, insole. Nothing fancy, but it does the trick.



    Midsole: The midsole is injected Ethylene-Vinyle Acetate (EVA) using New Balance’s proprietary Fresh Foam technology. This midsole compound is durable and reasonably long-lasting.



    Fresh Foam is used across a range of New Balance shoes and delivers good rebound and minimal degradation over time. The exposed portion of the Fresh Foam EVA midsole has an abrasion-resistant texture which has held up well.

    Outsole: The outsole of the FreshFoam Hierro Boa is a Vibram MegaGrip compound. Going back to 1937, Vibram has a long history of high-performance outsole compounds and designs.



    The MegaGrip compound is formulated to maintain traction and grip, even on wet surfaces. There are lugs of varying depth in the design—with the deeper lugs being on the ball and heel portion of the outsole.



    In addition to having a fairly deep design, the lugs form a pattern, which maximize grip in multiple trail conditions.



    Boa Fit System: The Boa Fit System started in the Rocky Mountains of Colorado and has been around since 2001. It is used on ski boots, snowboard boots, cycling shoes, and medical bracing.

    The Fresh Foam Hierro comes with a Boa Fit lacing system, instead of traditional shoelaces. There are three straps which cross the top of the shoe (think kids Velcro-type straps).



    These straps have a cord which runs through the ends, and into a Boa dial. Push/snap the dial-in and turn clockwise, and the cords tighten. Pull/snap the dial out, and the cords loosen.

    Liner: Instead of standard tongue in this shoe, there is a built-in bootie-type liner. This liner is a breathable, stretchable mesh. It is attached to the collar of the shoe and forms the tongue portion, which is fastened on the sides of the shoe, down by the insole.


    At first, I was skeptical of the overall durability of these shoes. The mesh upper, sock liner, and plastic Boa dials did not conjure up images of bomb-proof longevity and durability.

    That being said, I have been duly impressed with the toughness of this shoe. The uppers have held up well against the standard abrasions that one encounters on the trail. The plastic Boa dials have not had any issues, whatsoever.

    My disclaimer is that I have not fallen or scraped the side of the shoe where it would have caused a potential problem.

    However, I have been running in 10-40 degree weather, and the plastic has not appeared brittle, and the Boa fit system functioned flawlessly, even when covered in snow.

    The stellar component on this shoe has to be the Vibram MegaGrip outsole. This outsole has shown hardly any wear; even after using it on snow, ice, concrete, single track, and gravel.



    Maybe I am biased towards Vibram, but if I am, it is because I have had really good luck with the Vibram soles in the past. Kudos to New Balance for putting in an outsole on a show that is on the more expensive side: pay more, get more.

    Comfort and fit

    I have to admit that this is the first pair of shoes that I have run in, which have a built-in bootie liner. In the past, I have gravitated away from them for a few reasons.

    First, I normally run in low cut socks, and I do not like anything coming above my ankle. This is a personal preference.

    Second, I had it in my mind, that the built-in bootie liner would stretch out, and appear saggy, and not hold tightly around my ankle.

    Third, I am not a huge fan of the way they look (again, this is a personal preference). After logging some miles in the Fresh Foam Hierro, I can say that most of my reservations have been dismissed.

    I got used to the bootie above my ankle, and after a few runs in the snow, I began to appreciate it. The bootie did a great job of keeping the snow out, where I may have needed gators on a different pair of shoes.



    Whatever New Balance did to keep the bootie stretchy, and maintain its shape, worked. They fit as tightly now, as when they were new.

    As for the appearance, I am still not a huge fan, but this comes down to what you, as an individual like. If you are a fan of knit shoes like the Nike FlyKnit or some of the Adidas Ultraboost, then you will probably like these New Balance.

    The overall comfort of this shoe is excellent. They took no time to break-in, and even after moderate distances, they generated no hot spots. The Fresh Foam midsole worked well in balancing the right amount of rebound with the right amount of cushion.


    I would not describe this shoe as an all-day mountain running shoe, but by the same token, I would not hesitate to take these out for 3-4 hours on moderate terrain.

    The lug design of the outsole and overall ergonomics of the shoe, seem to lend itself toward trails that are “flowier”. When I was on these types of trails, this shoe seems to float over the terrain.

    I also think that this shoe handles admirably in loose conditions like sand and snow. I really think that this has to do with the Vibram MegaGrip compound, but I had a difficult time getting them to slip on ice (relatively speaking).

    What I like

    I appreciated the fact that these shoes were comfortable to wear from day one. If you try them on and get the sizing correct, you will not be disappointed with them.

    In fact, after a few runs, you will probably like them more. As I mentioned before, I really like the Vibram outsole. This sole is tough, provides omnidirectional traction, and inspires confidence on a variety of terrain. What did I like the most?

    The Boa Fit System

    I was skeptical at first, but the Boa Fit System provides an infinite amount of adjustment. Start off with your shoe too loose? No problem. Take 5 seconds and turn the dial a couple of clicks.



    Did you over tighten them, or are your feet swelling? Again, take 5 seconds, pop the dial out, push back in and tighten it to where you want it.

    The other part of the Boa Fit System that I like is that it has the three, wide straps across the top of the foot. This means that there are not tight portions, as there can be with a traditional lacing system.

    Not all feet are the same, and this Boa Fit System really allows for adjustments to the comfort of the wearer.

    What I don’t like

    My negative comments with this shoe are few. I am not a huge fan of the look. While if feels fast running, it looks somewhat slow.

    The straps and Boa Fit System that I love for performance, also, detract from the overall appearance of the shoe.

    Final review

    • Appearance 75/100
    • Materials 90/100
    • Longevity 90/100
    • Value for the Money 90/100
      OVERALL 86.25/100


    The New Balance Fresh Foam Hierro Boa show is an edgier looking shoe that provides excellent comfort, grip, and adjustability.

    Is this on the higher end of the price bracket? Perhaps, but you get what you pay for, and this shoe has a well-knitted, nice fitting upper, Boa Fit System, and Vibram outsole.

    There are a lot of features built-in here. If you are after a shoe that you can grab and just enjoy the run with, then the Hierro is a solid choice.


    This expert has been verified by RunRepeat. Reviews are neutral, unbiased and based on extensive testing.

  • 74 / 100 | Test 4 Outside | Level 3 expert

    We loved the design and material of the upper’s mesh: superb.

  • First look | Boa Fit System |

Become an expert

- The New Balance Fresh Foam Hierro Boa is a highly durable trail running shoe that offers a balance of comfort, style, and performance. 

- This New Balance trail running shoe utilizes a TPU-coated textile coverage that offers breathable coverage. The upper also incorporates the Boa® Closure System that allows the user to dial in a customized fit. 

- Providing plush comfort is the Fresh Foam technology integrated into the midsole of the shoe. This foam material offers optimal cushioning even on aggressive trails. 

- To provide maximum grip, the Vibram® MegaGrip outsole technology is utilized in the shoe. This outsole material delivers great traction in both dry and wet conditions. 

The New Balance Fresh Foam Hierro Boa is constructed using the standard sizing measurement. Runners can get a pair in their usual sizing expectations. However, it is advisable to try on the shoe first or utilize the general feedback about sizing to ensure a comfortable fit. 

The technical part that affects the fit of the shoe is the Boa® Closure System, which allows for a customized fit.

This running shoe utilizes the Vibram® MegaGrip outsole for superior grip on both wet and dry surfaces. The Vibram® MegaGrip outsole is lightweight and water-resistant. It prevents the feet from getting damp and protects the shoe from becoming damaged so quickly. 

Other popular trail running shoes that feature the Vibram® MegaGrip outsole are the Altra Olympus 3.0 and Hoka One One Speedgoat 3.

Just like the New Balance Fresh Foam Hierro, the New Balance Fresh Foam Hierro Boa also incorporates the Fresh Foam midsole cushioning technology. This component is precision-engineered to provide an ultra-soft and lightweight ride. It is designed to give optimal comfort and support for long runs. 

The bootie upper construction is designed to provide a supportive fit, reducing in-shoe slippage. The bootie construction and no-sew material application lessen the shoe’s overall weight and prevent the risks of rubbing and blisters. 

The breathable and flexible TPU-coated textile upper aims to keep the foot dry and cool throughout the entire running duration. 

Incorporated into the upper is the Boa® Closure System for a customized fit without pressure points. The Boa® Closure System is used as an alternative to the traditional lacing system. It allows the user to easily adjust the tightness around the shoe. 

The shoe also uses the Toe Protect™ technology. This component protects the foot from rocks, debris, and other elements.


Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.