Our verdict


A neutral shoe suitable for the trail, the New Balance Fresh Foam Hierro v4 received mixed comments from users. Positive reviews were about the shoe’s comfortable cushioning, great ground contact and pleasing design while the negative ones are about its fit, sizing, and durability. Overall, users thought that it is a good shoe that also needs improvement.


  • True to size
  • Wide toebox
  • Sock-like design
  • Plush
  • Comfy cushioning
  • Flexible
  • Excellent traction


  • Difficult to put on

New Balance Fresh Foam Hierro v4 review

The New Balance Hierro v4 is New Balance’s latest version of the rugged trail runner.  A few much-improved, albeit small changes from the Hierro v3.

Looks of the Hierro v4

The Hierro v4 didn’t change much about the look from the v3, but it did remove the “hypo-skin” that coated the entire upper on the v3.

The hypo-skin remains on the heel, and a bit on the mid-foot, but it doesn’t have the “wetsuit” look that the v3 did. That is about all that changed. Other than the 2 colorways for men and 2 for women.


In traditional New Balance fashion, the shoes run a hair small. But I am convinced that they are slowly turning from running small to fit a little more traditional in size.

This is very evident in the switch from v3 to v4. I wear a 9.5 and the length is always spot on, but the v3 had a tightness in the top of the foot and the toe box bordered on the uncomfortable realm.

In the v4, the toe box has been widened just enough, and the upper doesn’t squeeze the top of your foot. The opening in the shoe is still just as tight as with the v3, causing some annoyance in getting your foot in, but the tradeoff of a debris-less bootie is worth it.

I ran in 12 inches of snow and literally never got any inside my shoe. No gaiters required. The shoe itself is a single piece of fabric with little if any rubbing points. The sock-like entrance works as a makeshift gaiter to keep out debris.

Comfy cushioning

The sole of this shoe remains unchanged from the v3 and is like a chiseled work of art from Michelangelo. It lacks a midfoot strike plate, but it’s added cushion negates the need for one.

The midsole is made of New Balance’s Fresh Foam which is as comfy as it sounds. It is a single piece of foam material that runs the shoe's full length. It's plusher than the usual platforms and delivers a cushioning that feels soft and comfortable on the underfoot.

With this feature, combined with its flexibility, it grants a ride that feels natural yet responsive and protective. It lacks sharper points and grooves that some technical shoes might have (think, Salomon’s Speedcross or Saucony’s Peregrine), but it’s grippy Vibram sole makes up for it.

As I traversed to the top of a peak in inches of snow and ran back down in a packed down trail, not one time did I doubt my step. Not once did I feel like my grip wasn’t there for me.


Now to the hypo-skin that New Balance has adopted in a few of it’s latest model shoes. The skin remains a positive, but on the 3rd version of the Hierro, it was just not breathable enough.

They removed the skin from covering the upper in entirety and replaced it with a breathable skin in just the right places. You still have the benefit of the quick clean hypo-skin but adding a breathable upper and loosening the upper removed all hot spots from my feet.

Midsole & outsole

A nice thick 33mm midsole with an 8mm drop provides a great ride. The transition is pretty seamless on a shoe that looks to be sturdier in nature.

The Fresh Foam offers plenty of cushion, and protects your foot from any rough terrain the trail throws your way. The outsole is Vibram and offers excellent traction. The best of the best.

The Bad

If I were to point out any fault in this shoe, it would be the tight entrance. Thicker socks are what I normally wear, but I am hesitant to wear them due to the difficulty in getting the shoe on. That being said, it’s totally worth keeping debris out of the shoe.

Overall verdict

Looking for a trail running shoe that will stand out from the rest? Looking for grip that will make sure you get home without a newfound ability to do the splits? Looking for a shoe that just simply does its job? The New Balance Hierrov4 is the one.

Not to mention that the shoe is light and comfortable enough to manage the roads well if you ever have to get to the trail — no need to throw a pair in the backpack and switch.

New Balance sets an even higher bar with the new Hierrov4. The improvements over the 3rd version are just the ticket. You would be hard pressed to find a trail running shoe more enjoyable and more capable than this.