• Terrain


    Shoes best for road, track and light gravel. See the best road shoes.


    Shoes best for trail, off road, mountains and other unstable surfaces. See the best trail shoes.

    Good to know

    As long as you stick to the road or path, and if you want just one running shoe, buy a road running shoe.

  • Arch support

    Neutral / cushion / high arch

    Shoes for runners who do not need any additional arch support (Around 50% of runners). Best for people with normal, high or medium high arches. See the best neutral shoes.

    Stability / overpronation / normal arch

    Shoes for runners who need mild to moderate arch support (Around 45% of runners). Best for runners with a low arch. See the best stability shoes.

    Motion control / severe overpronation / flat feet

    Shoes for runners who needs a lot of arch support. Best for runners with flat feet. See the best motion control shoes.

    Good to know

    - Rule of thumb: If in doubt, buy neutral shoes to avoid injuries.
    - More about arch support in this video.
    - Find your arch type by following steps from this video.

  • Use

    Daily running

    Cushioned shoes for your daily easy running. Great comfort. See best shoes for daily running.


    Lightweight shoes good for races, interval training, tempo runs and fartlek. Here are the best competition running shoes.

    Good to know

    If you want just one pair of shoes, buy a shoe for daily running.

  • Price
  • Weight
    Men: 8oz
    Women: 7oz
  • Heel to toe drop
    Men: 6mm
    Women: 6mm

    The height difference from the heel to the forefoot, also known as heel drop, toe spring, heel to toe spring or simply drop.

    There are many opinions about what a good heel drop is. We do not recommend any in particular. Lean more in this video.

  • Heel height
    Men: 24mm
    Women: 24mm
  • Forefoot height
    Men: 18mm
    Women: 18mm
  • Width
    Men: Normal
    Women: Normal
  • Release date
    Feb 2016
Show more facts


A top rated Trail running shoe
A popular pick

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.

Are you an expert? Apply to contribute here.

82 / 100 based on 1 expert reviews

  • 82 / 100 | Trail Run Mag | | Level 3 expert

    Overall a great shoe for those tackling the many short course (5-25km) trail series taking place across Australia and New Zealand where event terrain tends to be softer, the trails less extreme without hard rocky sections, but where a need for grip, comfort and all weather wear is primary.

Become an expert

  • The All Out Crush Tough Mudder comes up with the best obstacle racing features that Merrell can create with the limited time they have. Without a doubt, the new 5mm lug configuration gives the shoe the kind of performance that makes it worthy to feature the Tough Mudder insignia in the upper.
  • The lugs provide a versatile grip on a multitude of surfaces in the most slippery conditions. Since the shoe is designed for travails in muddy conditions, the lugs prevent mud from accumulating and consequently weighing down the user.
  • The upper is waterproof and has drainage ports to efficiently shed water. For simple trail running, the waterproof protection makes it an all-weather friend in crushing the trails. As soon as the user takes the plunge into the water, the drainage ports quickly remove water from the shoe.
  • A sturdier, but lighter rubberized toe cap adds another element of protection in this shoe. It prevents the toes from getting bruised without taking much space in the toe box.
  • Finally, adequate reflective materials in the upper make it a suitable option for night-time or low-visibility running.

The fit of the Merrell All Out Crush Tough Mudder gives runners excellent hold and support that are not restrictive. There is sufficient space in the toe box for the toes to comfortably splay. It is designed for those with regular foot dimensions. The length runs true to size.

Merrell’s proprietary M Select rubber dominates the outsole. It is a proven compound in delivering awesome traction, even in wet conditions. This material is also used in the outsole of the All Out Crush Tough Mudder 2

Magnifying the effect of the M Select is the Pinwheel type of 5mm lug configuration. The lugs have adequate size and depth give the runners confidence in tackling obstacle courses or running on rough and rugged terrains when using the All Out Crush Tough Mudder.

A very simple midsole consisting of the Unifly foam runs the full length of the shoe. It has more cushioning and responsiveness than regular molded EVA. Because the foam covers the entire midsole, the transitions from landing to take-off should also be enhanced. Between the midsole and the outsole is a thin piece of TPU film that shields the foot from sharp objects.

A very breathable and waterproof upper covers almost the whole shoe. While the mesh is quite soft, the thin but abrasion-resistant TPU overlays add optimal support and midfoot hold. The tongue is a bit thick while the ankle collar is lightly-padded. A heel loop makes shoe entry and exit easier and more convenient. Merrell placed the Tough Mudder logo near the heel side on the lateral side of this shoe. Giving it more versatility are the reflective materials that make low-visibility activities doable. The M Select technology in the interior provides anti-microbial and anti-odor properties.