We spent 7.5 hours reading reviews from experts and users. In summary, this is what runners think:

10 reasons to buy

  • According to several reviewers, aside from extremely snowy conditions, the All Out Crush Shield’s water-repellent upper felt efficient when it came to staving off water, as well as dirt and mud.
  • Many consumers thought that the price of this shoe is affordable.
  • The lightweight nature of this shoe was welcomed by a lot of those who have tested it.
  • The drainage ports were able to filter out water with ease, commented some satisfied trail running enthusiasts.
  • The grip capability of the 5mm lugs was lauded.
  • A handful noted that the Shield version of the All Out Crush is quite stylish.
  • The 5mm lugs hold on to soft and mucky conditions.
  • There were persons who appreciated the roomy toe-box, which allowed their toes to splay naturally.
  • More than a few runners valued the arch support coming from the Shield version of the Merrell All Out Crush.
  • A couple of expert reviewers praised the fast turnover through the gait cycle.

4 reasons not to buy

  • Some runners mentioned that the underfoot platform was a bit stiff.
  • Despite the 5mm lugs and the rock protection plate, a handful of testers felt some underfoot pinching when running on rocky ground.
  • The forefoot section of the upper unit felt too wide, according to a several purchasers.
  • The outsole showed early signs of wear and tear, based on the observations of a handful of runners.

Bottom line

The Merrell All Out Crush Shield is the water-repellent version of the standard model. It is marketed to obstacle course lovers and trail runners alike. Merrell designs the shoe for soft and muddy surfaces with all-weather comfort in spades. With a very reasonable price, this is a solid option for those who need a grippy and fast partner that can take the runner from the door to any water-soaked outdoor surfaces.


Base model: Merrell All Out Crush
Terrain: Trail
Arch support: Neutral
Weight: Men: 15oz | Women: 15oz
Heel to toe drop: Men: 7mm | Women: 7mm
Pronation: Neutral Pronation
Arch type: High arch
Use: Jogging
Waterproofing: Water repellent
Strike Pattern: Midfoot strike
Distance: Daily running | Long distance | Marathon
Release date: Jul 2016
Brand: Merrell
Type: Heavy | Big guy | Low drop
Width: Men: Normal | Women: Normal
Price: $110
Colorways: Blue, Green, Grey, Orange, Purple
Special editions: 1 special editions
Small True to size Large
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Expert Reviews

Experts are runners, who post reviews at youtube, directly at RunRepeat or at their own websites. Each expert is categorized from level 1 to level 5 based on expertise. See stats on expert reviews and how we calculate scores here.

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80 / 100 based on 4 expert reviews

  • 80 / 100 | River Rock Outfitter | Level 1 expert

    If you are looking for a lightweight, responsive trail runner, this is gonna be the way to go.

  • 85 / 100 | Runner's World | Level 5 expert

    Using a mesh upper wrapped in a plastic-like coating, the All Out Crush Shield will keep water out where it belongs in most situations. That construction, however, doesn’t hinder forefoot flexibility—the men’s model bends easiest among all shoes in this guide.

  • 80 / 100 | iRunFar | | Level 4 expert

    What’s new? The upper. It’s got TPU overlays for mud and water shedding along with a breathable tongue that aims to offer protection from morning dew or occasional mud. It’s got a moderately aggressive outsole and a 7mm drop.

  • 70 / 100 | Outside Online | | Level 2 expert

    That said, Shield is a misnomer: the lack of a rock plate made high-alpine jaunts and extended stony stretches distractingly uncomfortable, especially on runs over an hour. 

Become an expert

  • Merrell brings the water-repellent version of the All Out Crush to those who love an all-weather challenge as part of trail running or tackling obstacle courses. With a water repellent upper, the shoe keeps the foot fairly dry and breathable at the same time. In ankle-deep water or heavy downpour, the upper also dries quickly to limit the possibilities of blisters.
  • The 5mm lugs provide leverage on soft or muddy ground. Merrell places the lugs at strategic intervals to prevent mud from caking, which is highly-beneficial when taking on soft or loose ground.
  • Reflective materials on the upper make it an excellent option when visibility is low.

The All Out Shield has a standard fit and hold in the heel and midfoot. It wraps the foot without being restrictive. The toe box is very spacious, which should be excellent for those with bunions or those with inflexible or flat feet. It runs true to size.

Merrell covers the entire section of the outsole with its proprietary M Select Grip for sticky traction, even in wet conditions. There are 5mm lugs that are scattered all over the underfoot, from heel to toe for a superior bite on tricky and wet surfaces. These lugs are also ideally built to handle the challenges of obstacle course racing.

The unique is quite simple as it features only the brand-exclusive UniFly technology, which is a molded foam that has optimal responsiveness and adequate stability. It runs the whole midsole and helps the transition from landing to take-off much smoother. Merrell’s UniFly technology is quite durable despite being very light. The All Out Crush Shield gives a nice mix of cushioning, ground feedback, and pop with every stride because of this foam. A rock protection plate straddles the boundary between the midsole and the outsole for protection against sharp objects on the trail.

Merrell’s typical upper construction is simple and very functional. It has a well-ventilated mesh that is covered with TPU water resistant features. The quick-drying upper is also another asset of this shoe. There are reflective elements for night-time or low-visibility running. A protective toe cap lessens the potential of bruises in the toes. The cushioning and support are enhanced by the presence of a fixed insole.


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.