Saucony Freedom ISO review

The Saucony Freedom ISO is a versatile performance trainer for the neutral runner. It has a heel-toe drop of 4mm (23mm in the heel and 19mm in the forefoot) and weighs in at 9.0oz/255g for a US 9.

The Freedom ISO is a fresh model from Saucony that comes with a feature that makes it stand out from the rest of the market. The Freedom ISO competes with the likes of Adidas Boston Boost 6, Nike Zoom Fly, Brooks Launch 4, Asics Dynaflyte 2 and New Balance Zante v3.

Upper of the Saucony Freedom ISO

Saucony uses a dynamic ISOFIT system that adapts to the shape and motion of the runner's foot. I found the upper plush yet minimal. The Engineered stretch mesh upper is extremely lightweight and is also breathable. I never once felt like my feet were heating up during runs of any speed.

The upper is one of the most comfortable uppers I have ever worn, coming right behind the first version of the Under Armour Speedform Fortis. I felt that the upper did exactly what Saucony claimed; the stretchy mesh conformed well to my foot and yet provided an adequate structure to hold my foot over the midsole without any pressure points.

Overall, the upper wins a place in my books as one of the best fitting and most comfortable uppers in lightweight trainers.

Heel Cup/Ankle Collar

Moving on to the heel. The Freedom utilizes a heel support frame to further cut down on weight to the upper.

The support frame was made with the intention to support the heel without the additional weight of a heel cup. I found this feature rather redundant. It adds unnecessary weight while providing the same amount of support as a Nike Free Run Flyknit.

In simple terms, the heel support frame does nothing to support the heel. I understand the reasoning behind the support frame (the shoe is called the Freedom for a reason) but Saucony should have discarded the frame from the start.

Tongue & Lacing of the Freedom ISO

The tongue is thin and minimally padded but provides the right amount of pressure to prevent any lacing tension on top of the foot.

The padding on top of the tongue combined with the flat laces ensured further help with the distribution of lading pressure. However, the padding looked kind of strange.

This is more of an aesthetic issue for me and can be looked over considering the fantastic overall build quality the shoe brings to the table.

The lacing is unique.

The Engineered mesh forms 3 “band-like” loops that replace the traditional eyelets found on most running shoes in the market. This lacing system allowed the upper to hug around my foot like a burrito, giving the upper a versatile fit for varying foot widths.

Overlays are placed on these “bands” to reinforce them, further enhancing its durability.

The Freedom ISO runs true to size

I have rather wide feet, and the Freedom accommodates my feet nicely without squeezing my toes together. However, a couple of my friends had to size up half a size to accommodate their wide feet. I recommend trying on the shoes at a local store before deciding on getting a pair.


I absolutely love the design and colorway of the shoe. Although the design on the top of the tongue looked strange, the strategic placement of the yellow-orange colors on the upper and midsole and low stack heights made the shoe look fast and sleek.

I would love to see Saucony come up with a racer with a stack height of about 12mm of Everun in the forefoot and 16mm in the heel, utilizing a softer carbon rubber variant for the outsole and a Pebax shank extending from the midfoot to the forefoot. I believe that this racer will be one of the most responsive yet cushioned racer.

Midsole Tech & Ride Quality

This is where the magic happens. The Midsole comprises a full-length Everun foam complimented by a 2mm Everun topsole with a 4 mm heel to toe drop.

Everun is made of TPU ( Thermoplastic Polyurethane) foam which is made to be bouncier, softer, and more durable than standard EVA foam that many shoes use. I was skeptical about the Everun topsole technology in the other Saucony models as there was only a thin layer of it which made it seem insufficient and gimmicky.

The Freedom ISO changes everything! I had never been so excited to have so much Everun below my feet. Sure, Adidas has their boost technology but most of their shoes feature a thin layer of EVA foam to stabilize the soft boost midsole.

The models with a full boost midsole either weigh above 300g or are too soft and unresponsive to run at quicker efforts. With the Freedom ISO, I enjoyed an undiluted experience of TPU foam bouncing below my feet with each step.

The Everun was claimed by Saucony to “produce a dramatically livelier and more responsive feel, 83% energy return and maintains its properties 3x longer than standard EVAs”

Everun was indicated to feel roughly 10% firmer than boost foam. This provides a more stable and responsive feel without losing the desirable attributes of the TPU.

I found that landing on the forefoot was firm but bouncy and landing towards the heel was towards the softer side. This allowed for more cushioned landings and faster toe- offs.

I could not tell that the Everun Topsole was present but I'm sure that it contributed to the overall bouncy feel of the Midsole.

At Uptempo speeds, the ride quality was one of the best if not the best that I have experienced. Many Uptempo shoes give a responsive ride but lack the bouncy characteristics of the TPU foam that makes this shoe so much fun to run in.

However, there are some drawbacks to the midsole of this shoe. For longer runs, the shoe started to feel “bottom-heavy” due to the weightless upper paired with the heavier midsole.

This made me feel as if I was on top of the shoe instead of being in the shoe. Also, due to recurring shin splints, I usually run in shoes with more cushioning for anything more than an hour. I decided to test the shoe for a 15km recovery jog and regretted it immediately.

I felt that the protection the midsole and outsole gave was inadequate for my sensitive shins on the longer miles. However, it shouldn't pose a problem for those without injuries.

Freedom ISO Sock liner 

The sock liner is rather standard with minimal targeted padding on the heel and forefoot. I switched the insole out for my personal insoles for a better ride.

Outsole & Durability of the Saucony Freedom ISO

The outsole uses a single, full-length slab of crystallized rubber that runs from the front to the back of the shoe. The newly introduced crystallized rubber is unlike any other outsole manufactured by Saucony,  presenting both pros and cons which will be addressed below.

This outsole design gave the shoe a very uniform feel from heel to toe which translated into smooth transitions from impact to toe-off. The crystallized rubber came in a bright yellow color. Personally, I preferred if they utilized the Orange-Yellow outsole color pattern with the blue upper.

The crystallized rubber is incredibly durable. I have about 200km in my pair and the outsole shows minimal signs of wear! I expect the outsole to last as long as or longer than the typical daily trainer.

However, I noticed that the crystallized rubber did not provide adequate grip during runs in wet conditions. Whether it was the road or the track, i would occasionally slip and lose my footing. Because of this, i would never pick up the Freedom for a run when it was raining or if the floor was wet.

  1. Weight of 65kg (154lb) and above
  2. Running pace of 4:00km/min to 5:00km/min
  3. Preference for cushioned & durable Shoes
  4. Neutral gait
  5. Wants a flashy shoe that would turn heads

Potential areas for improvement

  1. Add a minimal heel counter
  2. A Slight reduction in weight
  3. Tweak outsole configuration to enhance grip in wet weather conditions


Saucony Freedom ISO vs Altra Escalante

The everun midsole in the Freedom is firmer than the Escalante. As much as I enjoy the EGO midsole in the Escalante, I dislike the slight negative drop of -1mm as I usually run in shoes with a heel to toe drop of 4-10mm and this negative drop tires my calves and Achilles. Unless you are into low drop shoes, pick the Freedom.

Saucony Freedom ISO vs Kinvara 8

The Kinvara 8 is softer but lacks the bounce the Freedom offers. Despite being 30grams heavier, the Freedom is more responsive and is an overall faster shoe. The only situation where I would pick the Kinvara over the Freedom is for long and slow runs.

Saucony Freedom ISO vs Asics Dynaflyte

The Freedom is much bouncier than the Dynaflyte though both shoes have great vibration-dampening in their midsoles. Both uppers are equally as comfortable.

One with wider feet or a preference for bouncy cushioning should opt for the Freedom while a person with narrower feet or a preference for firmer cushioning should consider the Dynaflyte.

Saucony Freedom ISO vs Nike Zoom Fly

The  Saucony Freedom ISO is much more flexible compared to the extremely stiff Zoom Fly. I would prefer the Zoom fly over the Freedom for paces of 4:15min/km and below, the Freedom for everything else.

Facts / Specs

Terrain: Road
Weight: Men 9oz / Women 8.1oz
Drop: 4mm
Arch support: Neutral
Update: Saucony Freedom ISO 2
Forefoot height: 15mm
Heel height: 19mm

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Samuel Chua
Samuel Chua

I'm Samuel, a recreational runner, and a triathlete. I have taken part in over 30 races and 17 triathlons so far. I have an avid passion for running gear, especially running shoes. This obsession with running shoes has helped me obtain vast knowledge on each brand's technology, which led to me trying shoes from many different brands and giving unbiased opinions on the performance of each shoe.