Asics Gel Flux 4 Fully Reviewed and Tested

8.0 score
Runnerclick score (8.0)/10

Our overall Runnerclick score is based on 3 different factors: Editor's rating after in-depth testing. User ratings submitted on this page Overall score from the "reviewmeter" based on reviews across the web the weight of each factor is: 40% editor rating 15% user ratings 45% reviewmeter
Editor rating: 8.1 / 10
User's rating: based on 5 user ratings
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Asics Gel Flux 4 Fully Reviewed and Tested Review Facts

At a reasonable price that will put a smile on your face, the Asics Gel Flux 4 running shoe is a great start to any running career or as a sturdy daily trainer for running on roads. While it may not feature all of the bells and whistles of some of Asics other expensive styles or shoes formulated for more specific terrains, the brand didn’t hold back on the necessary characteristics of quality that Asics has been known for since the company was founded in 1949.

With its Trusstic System®, Guidance Line®, and Rearfoot and Forefoot GEL® Cushioning System technologies and DuraSponge® and AHAR® rubbers (plus many more features!) this shoe has the comfort, support, durability, and breathability you need to log on those miles. Whether you’re looking for a durable everyday shoe that will take a beating on your long road runs while still providing the comfort you need, or if you are an entry level runner looking for your first shoe, there’s a good chance this is the shoe for you. Since its release in January 2017, the Asics Gel Flux 4 has enjoyed the same popularity among entry-level and light road runners that it’s predecessors did.

Editor's Pros & Cons
  • Good price
  • A sturdy, economical shoe
  • Perfect shoe to wear for the gym
  • Airy mesh and stitching-reinforced overlays
  • The insole can be easily removed 
  • More stylish than some of the previous Gel Flux shoes
  • A few runners have complained of a loose fit
  • Not as light as hoped by some runners
See How
Reviews were analyzed here:
We read, analyze and sort reviews into positive & negative categories to give you the complete picture.
What are buyers saying?

We have spent 4.8 hours analyzing a total of 422 reviews.

These reviews are then categoried into "Positive" and "Negative" feedback.

Below you will read a summary of them:

  • These Asics fit a bit more stiffly than other Asics runners, but once you break them in, they are very comfortable.
  • There is good heel and toe support in these Asics, and I find that they are great for high impact sports.
  • These shoes fit true to size, and they are supportive and comfortable.
  • The Asics Flux 4 shoes not only offer fantastic support and cushioning, but they come in a great selection of colors.
  • The main reason for repeated purchases is mainly because the arch support is top notch.
  • They are actually really good for multiple types of workouts, far beyond running.
  • The toe box is nice and wide; however, I went up half a size.
  • The Ascis Flux 4 fit well right out of the box, and they didn't require a lot of break in time, but I did need to go up half a size.
  • There are quite a few purchased based on how well they work for people with back pain
  • This one is also pretty popular and supportive if you have a pronation issue.
  • The support that works well for pronation issues also works for those with flat feet.
  • Overall, these shoes offer comfort, great fit, and come in bright colors that are very pleasing. They also offer wonderful arch support that are not often found in a lot of shoes with basic support in their design.
  • A lot of people comment that these are also great for walking.
  • The Asics Flux 4 are very durable and versatile. They are my favorite of all the Asics runners.
  • Besides the solid arch support, the overall comfort is something mentioned by a lot of customers.
  • They really don't seem to require much break in time.
  • According to many customers, these are a great choice for people who need to be on their feet for long periods at a time.
  • That same support that aids issues with pronation and flat feet is also ideal when it comes to other conditions such as plantar fasciitis.
  • Running inclines on a treadmill or roads doesn't seem to affect the shoe or the wearer. The overall fit keeps the shoe on right.
  • This seems to commonly be a good alternative to the cumulus for those who like to stay with one brand.
  • These particular shoes are less cushioned than other Asics runners. However, with gel inserts, they were much better.
  • They seem like they're bulkier than they really should be. The weight is a little heavier as well.
  • These shoes do not feel as cushioned as the Asics Nimbus.
  • The overall fit is decent, but noticeably smaller than the last version.
  • Although it isn't the case as much, there are still some earlier customers who felt the sole was stiff for quite a while.
  • These were very comfortable, but a hole developed in the toe section.
The Reviewmeter shows you an overall score that you can easily refer to. The highest rating is 10 (100% positive feedback)
Of the 422 reviews we found in total, 20% were negative, and 80% were positive.


The brand’s standard Guidance Line® technology is featured in Asics Gel Flux 4. The Guidance Line® is a synthetic insert that acts as a physical separation between the midsole and outsole, helping to provide a consistent load transfer during the stage of propulsion and at the peak of acceleration (improving gait efficiency and in turn helping to prevent injury).

Asics have used their durable AHAR® (Asics High Abrasion Resistant Rubber) in the areas of the shoe that are exposed to more wear and tear, producing longer lasting protection from the elements and terrain.

Asics DuraSponge® rubber, which is a softer rubber, is located in the forefoot to provide extra cushioning and added traction to the shoe.


As mentioned above, the Guidance Line® technology (also known as a vertical flex groove) used in Asics Gel Flux 4 will improve gait efficiency and energy transfer efficiency by decoupling the tooling. The SpEVA® Midsole Material boosts your energy return through a specialized spongy foam and rubber material by literally giving you a springier step.

Asics testing shows that SpEVA® provides a 20% bouncier, lightweight and responsive rebound. This means that with the same effort you normally put into your stride, you will now be rebounding 20% faster - that can only mean good things for the miles you put in and the comfort your joints and knees need.


Here in the upper is where some changes can be noted from the Gel Flux 4’s predecessors. Asics made an effort here to provide improved breathability and comfort, through a softer mesh with bigger holes and a more conforming fabric that will easily adapt to a runner’s foot. Also different in this edition is the removal of thicker stitching in the forefoot overlays - in this shoe, the stitching is seamless with synthetic overlays that should alleviate any risk of irritation and give the forefoot more breathing space, while also giving the shoe support and security.


Another of Asics’ staple technologies is the Guidance Trusstic System®, which is formulated to enhance your gait efficiency while maintaining midfoot structural integrity and reducing the overall weight of the shoe. The men’s Asics Gel Flux 4 weighs in at 12.4oz, and the women’s version is a lightweight 9.1oz. Not bad for a shoe that packs in most of Asics trademark technologies while still retaining its energy efficiency, durability, and comfort that runners have come to expect.


The breathability is considerably updated in the Asics Gel Flux 4, with an improved nylon mesh material that is both softer and airier with bigger holes in the mesh that covers the entire synthetic upper section. The breathable mesh underlays are designed to optimize airflow while you are running. With this difference, it’s easier for the air to systematically get into and out of your shoe, in turn keeping your foot cool and dry.


The much loved Rearfoot and Forefoot GEL® Cushioning Systems of previous models, a key to Asics footwear for over two decades, have been happily kept in this version. These cushy gel inserts are located throughout the shoe at key impact zones and attenuate the shock of vertical impact forces.

As the foot moves through the line of progression, these systems reduce the pressure and stabilize the foot. This allows for a great deal of comfort without lowering economic productivity. For additional comfort, the Asics Gel Flux 4 also features a padded tongue and collar, breathable mesh upper, cushioned insole, and soft lining.


In this model, Asics opted to veer away from their standard bold colors and instead created a pleasant, ombre design available in several colors.
The subtleness of the shoe is offset by the familiar flashing Asics logo, with the reflectiveness as always offering more visibility for a runner and therefore helping to make your run safer.

The lace-up closure is snug and produces a comfortable, figure-hugging fit while the built-in breathability keeps your feet aired out even on the longest of runs.
The new, thinner overlays look more stylish than previous versions, and a rubber toe bumper on the tip of the shoe finishes off the look and ensures durability and safe toes.


The SpEVA® Midsole Material used to increase the spring in your step also reduces the chances of your midsole breaking down by making your foot’s rebounds more economical. In addition to this benefit, the durable material AHAR® (Asics High Abrasion Resistant Rubber) is used throughout the Asics Gel Flux 4 in key wear and tear zones to create a protective barrier against the elements and in turn, increasing the longevity of the shoe.


Again, the trademark Asics AHAR® rubber comes into play here by protecting the outsole of your shoe with the rubber’s tough durability and location in crucial areas that will be consistently exposed to the terrain. A solid rubber bumper is positioned on the front of your shoe, protecting your toes while increasing the durability of the shoe. The lace-up closure is secure, providing a protected fit for your foot and helping to prevent injuries.


A key part of responsiveness for the Asics Gel Flux 4 is found in the spongy rubber of the trademarked SpEVA® technology in your midsole. The lightweight spring that it provides ensures that when your foot hits the ground, you get the most out of your step and gravity, allowing you to run longer and harder with better results. The lighter weight of the shoe, thanks in part to the Guidance Trusstic System®, ensures that you are not running with a heavy step and therefore are able to respond more quickly to different conditions of the road.


Asics Gel Flux 4 is primarily designed for one terrain: the asphalt road. Whether that be your neighborhood or pathways in the park, you can rest assured that the increased rebound efficiency and a blend of durable and soft rubbers at key spots throughout the shoe will provide you with a comfortable run. While it may be used for other terrains such as light off-road or gravel, this version is not intended and not recommended for tougher surfaces like proper trail running.


As mentioned above, the price range for the Asics Gel Flux 4 is very, very reasonable, especially considering the tightly woven blend of several of Asics’ best technologies in a reduced weight shoe. In many cases of life, you really do get what you pay for, but in this case, the resources and experience of a successful global brand such as Asics allow you to purchase one of the best durable daily runners for the economical price offered. This shoe is perfect for the budget conscious or entry level runner - don’t let the words entry level fool you though, you are getting solid quality for an unquestionably fair price.


As do almost all of the Asics brand running shoes, the Gel Flux 4 edition offers excellent traction for the terrain in which it is intended (which in the case of this shoe is mainly asphalt). The combination of the Guidance Line® technology (also known as a vertical flex groove) improving your gait and the sturdy, resilient AHAR® rubber that is used on the outsole providing a strong grip and good purchase on the road ensure that for what you are paying for, this shoe has great traction.


The cushioning of the Rearfoot and Forefoot GEL® Cushioning Systems not only make the Asics Gel Flux 4 comfortable but also play a very important role in how your foot flexes with the shoe. These systems work closely together with the Guidance Line® technology to create a consistent load transfer during the stages of impact and propulsion. Combined with the variously specialized rubbers used throughout the shoe, this means greater flexibility for the shoe.


The Asics Gel Flux 4 has moderate stability for the average runner. If you are a neutrally positioned runner or naturally underpronated runner, it offers excellent stability. The shoe achieves its stability by utilizing the Guidance Line® technology (also known as a vertical flex groove) and Guidance Trusstic System®, which strengthens the midfoot structural integrity by mirroring the action of your foot’s ligaments.


Heel to toe drop, also known simply as ‘drop’, or in the shoe industry as ‘pitch’, is the difference in the height of a shoe from the heel to the forefoot.
The heel height for the Men’s Asics Gel Flux 4 is 23mm, while the Women’s is a 22mm; and the forefoot height for the Men’s shoe is 13mm while the Women’s shoe is 12mm.

This means that the heel to toe drop in both shoes is about 10mm, which is a fairly standard sized drop that is found across a broad spectrum of Asics running shoes. This sized drop provides a runner with a good amount of cushioned comfort while not being too ‘marshmallowy’.
Key Features

Key Features

- Guidance Line® technology
- AHAR® (Asics High Abrasion Resistant Rubber)
- DuraSponge® rubber
- SpEVA® Midsole Material
- Guidance Trusstic System®
- Rearfoot and Forefoot GEL® Cushioning Systems
- New and improved seamless stitching and thinner, synthetic underlays
- New and improved soft nylon mesh
Bottom Line

Bottom Line

For the budget conscious, entry level, or daily roadrunner, it’s hard to beat the reasonable price for the solid quality and performance you will get out of this shoe. It’s both durable and comfortable, benefiting from the Asics’ brand well-known breadth of knowledge and research with tried and true running technology.

It’s an everyday warrior type of running shoe - if you’re looking for fancy bells and whistles or for a shoe that’s appropriate for terrains other than asphalt or light off-road/gravel, you are going to want to look elsewhere.

However, if all you want and need is an energy efficient, comfortable, resilient shoe with good breathability and endurance - look no further! The Asics Gel Flux 4 will not disappoint, and the very sensible price will keep you smiling for many days after you purchase this reliable shoe.