Facts

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  • Terrain

    Road

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

    Trail

    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.

    Competition

    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
    $110
  • Weight
    Men: 6.9oz
    Women: 5.2oz
  • Heel to toe drop
    Men: 8mm
    Women: 8mm

    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: 17mm
    Women: 17mm
  • Forefoot height
    Men: 9mm
    Women: 9mm
  • Width
    Men: normal
    Women: normal
  • Release date
    Unknown
Show more facts

Summary

We spent 6.6 hours reading reviews from experts and users. In summary, this is what runners think:

8 reasons to buy

  • This is a road racing flat that offers a barely there feel, says some of the testers.
  • The glove-like feel is nice and secured, and there is no slippage is experienced, as commented by some testers.
  • The toe box is great for wider forefoot runners.
  • The M Select FRESH keeps odor off by maintaining a healthy environment for the foot.
  • It is a flexible shoe.
  • The Protective Toe Cap efficiently shields the forefoot area from incoming debris or hard surfaces.
  • Forefoot strikers can easily take advantage of its no-bulk design.
  • It has a lightweight nature.

3 reasons not to buy

  • The outer tread of this running shoe began to come off for some runners after only a few months.
  • The minimal cushioning left some runners feeling some discomfort when traversing the trails.
  • There were complaints saying that the Toe Cap kept hitting the toes of those wearing it, causing discomfort and irritation.

Bottom line

The Merrell All Out Flash is a versatile running shoe for different running routines. Speed running is a lot easier and more efficient thanks to this model, provided that the runner employs a minimalist or barefoot running style. Because of the lack of cushioning, it is not for heavy runners and runners with concerns with foot pronation, but it works well for neutral runners.

Rankings

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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89 / 100 based on 1 expert reviews

  • 89 / 100 | Running Competitor

    Merrell’s All-Out Flash has some of the best design elements of minimalism while also offering a softly cushioned ride.

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Updates to Merrell All Out Flash

  • Merrell’s reputation, when it comes to lightweight shoes with numerous minimalist features, continues to grow in the All Out Flash. The raised heel gives it more protection on the road, but still maintains that nimble feeling when looking for more speed. With a decent stack height and a medium 6mm heel offset, Merrell enables a smooth and effective rolling of the foot from impact to take off.
  • The All Out Flash offers an upper that sticks like a second skin for unbelievable next to skin feel. While there is plenty of natural movement allowed in this shoe, the midfoot is securely locked in while the heel lock holds that part from any slippage.
  • Merrell’s aim to add cushioning in the All Out line gives this shoe better cushioning for such a lightweight shoe. As this has improved cushioning, it can also be a very solid option for uptempo trainings or daily long-distance runs.

Merrell All Out Flash size and fit

Merrell made the fit pleasantly snug in the heel to the midfoot before it becomes a wide forefoot. Road racing shoes that offer this kind of fit usually benefit a large number of runners as it allows plenty of room for the toes to splay. Medium is the available width of the All Out Flash. Sizing bang on in this shoe and offered from 7 to 15 for the men’s and 5 to 12 for the women’s.


Outsole

The lugs in the outsole are moderately aggressive and covered by Merrell’s own M Select Grip outsole. With this kind of lug a configuration and the sticky nature of the rubber in the outsole, runners are assured of a bite that makes runners very confident.


Midsole

The minimal stack height houses the Merrell-exclusive UniFly midsole, which is made of premium EVA and proprietary elements to form a lightweight, durable, and very responsive midsole foam.


Upper

A durable and incredibly breathable AirMesh covers a large majority of the upper. TPU overlays provide structural support and a more dialed-in foothold. A durable and flexible toe bumper protects the foot from bruises. Merrell also gives option to runners who are looking for more cushioning as it has a 2MM insole. Regular laces called the Omni Fit by Merreell enhance personalized fit and comfort.