Inov8 F-Lite Max review

We think that the Inov8 F-Lite Max should be on your radar if you are in search of a cross-trainer that:

• is ideal for strength training with heavy loads
• comes with a stiff TPU heel (akin to lifting shoes)
• has the biggest toebox in town

If you include a lot of high-impact exercises, plyometrics, or interval runs into your training routine, we recommend choosing a more well-rounded alternative to the F-Lite Max.

The Reebok Nano X4 and the Nike Free Metcon 6, for example, are some of the best gym shoes when it comes to versatility. Both are better cushioned and are more agreeable for walking as well.

Measuring the heel stack of the F-Lite Max, our caliper recorded an above-average reading of 27.7 mm. While we wouldn't call it tall, it is taller than the popular Nike Metcon 9 (21.5 mm).

Looking at the cutaway midsole of this Inov8 shoe, you can see that its stack comprises a notably thick insole as well as a massive TPU heel stabilizer in addition to the primary midsole foam.

As for the shoe's forefoot stack, we found it to be on par with the average at 18.6 mm.

Because nearly half of it is taken up by the cushy insole, we were pleasantly surprised with the responsiveness the F-Lite Max offered under the balls of our feet.

But while it makes the shoe more accommodating for high-impact cardio bursts, the stiff and chunky heel holds the Inov8 F-Lite Max back from being the best HIIT trainer. We found that its design is more biased towards lifting and Crossfit but more on that below.

The brand explicitly states the shoe's heel-to-toe drop on the back of the midsole - 6 mm. 

But as much as we wanted to confirm that number, our caliper said otherwise - 9.1 mm. Inov8 must be using a different approach to measuring drop because its stack measurements are also drastically different from our findings - 14 mm and 8 mm, respectively.

However, a slightly higher offset doesn't make the F-Lite Max a bad cross-trainer! In fact, a bit more heel elevation benefits squats and heavy lifting as it prevents the Achilles from overstretching.

One of the primary reasons why we confidently recommend the Inov8 F-Lite Max for lifting and Crossfit is its firm and stable platform.

Its Powerflow Max midsole is some of the firmest foams we've seen on a training shoe with a durometer reading of 35.0 HA (25% firmer than average).

What's more, the shoe's incompressible TPU heel makes the F-Lite Max feel a lot like a crossover between a trainer and a lifting shoe.

Pressing our durometer against it returned a whopping reading of 88.0 HA which is on par with what we get in the TPU heels of lifting shoes!

We were able to lift up to 300 lbs (135 kg) without experiencing any destabilizing compression underfoot!

So far, the Inov8 F-Lite Max comes across as unforgivingly hard underfoot. And that would be true if it wasn't for the shoe's amazingly cushioned Boomerang insole.

It is nearly twice as thick as the average training shoe insole at 7.2 mm!

Made of hundreds of tiny balls (kind of like Adidas Boost) with some energy return to them, this insole buffered our feet from the hard platform very nicely. Doing high-impact exercises would feel punishing without it.

Seeing the Inov8 F-Lite Max for the first time made us worried that we had mistakenly ordered the shoe's wide version. Its toebox was MASSIVELY large.

But upon double checking, we realized that this trainer is, in fact, offered in Wide fit by default, and according to the brand's size and width chart, the widest area of the forefoot should come in at 100 mm in a men's US size 9.

But when we applied our caliper to the mentioned toebox area, it showed an even bigger reading of 103.8 mm. This width is normal for high-performance Crossfit shoes like the Metcon 9, for example, which has it even wider at 108.0 mm.

However, it's the F-Lite Max's toebox shape that makes all the difference...

Measuring the shoe's dimensions at the big toe mark, our caliper returned an abnormally high reading of 89.4 mm! That is the widest we've recorded among the training shoes in our lab.

But we can't complain because having this much toebox space allowed us to splay toes as much as we needed to find balance for strength straining.

It also makes the F-Lite Max a perfect match for gym goers with wide and even VERY wide feet. On the other hand, we believe that narrow footers should stay away from this Inov8 shoe for the same reason.

As the shoe's strongest suit, stability is the reason to buy the Inov8 F-LIte Max. We could even trust this Inov8 trainer with our PR-level weight!

In addition to being incompressible under heavy load, its TPU Heel Stabilizer provides excellent lateral stability. Enhanced by the rubbery Met-Cradle cage around the midfoot, it makes the foot immune to buckling over during high-intensity exercises.

Testing the shoe's torsional rigidity in our manual test, we found that its platform is frozen stiff from the midfoot to the heel. So much so that we gave it a high stiffness score of 4 out of 5.

Inov8 leaves just a touch of pliability in the forefoot to make the F-Lite Max versatile enough for dynamic exercises.

Even though we didn't find much rigidity in the shoe's heel counter, it didn't seem like the trainer lacked heel support because of that. On a 1-5 stiffness scale, we rated its heel counter as low as 2.

The Met-Cradle around the midfoot and the sturdy platform underfoot generated enough support to keep our foot locked in and steady.

There is no kidding when Inov8 promises your toes "room to splay." The midsole of the F-Lite Max replicates its toebox shape and stretches as wide as 113.0 mm in the widest area.

A few millimeters wider than average, it creates very large side flanges to lean on.

Measuring the heel of the F-Lite Max, we were surprised to see a below-average reading on our caliper.

But even though the widest part of its heel comes in at 83.1 mm, we never felt as if the platform was lacking. The heel stabilizer did its part brilliantly!

Lined with deep flex grooves, the forefoot portion of the F-Lite Max offers enough flexibility for jumps, lunges, burpees, push-ups, and more.

Our gauge measurement revealed that at 16.3N, this Inov8 shoe requires just as much force to bend to a 90-degree angle as the average cross-trainer.

We don't expect a shoe with large TPU stabilizers to feel light as a feather. Neither does it make for the best HIIT and cardio companion.

But we were glad to discover that the Inov8 F-Lite Max was not the heaviest trainer in our catalog.

At 12.1 oz (344g) in a men's US size 9, it weighs less than the acclaimed Metcon 9 (13.4 oz/378g).

Designed for workouts that make you sweat hard, the Inov8 F-Lite Max is also there to take care of the moisture.

Its entire toebox is made of a paper-thin airy fabric that feels almost nonexistent on top of the foot. Our transparency test below is a perfect demonstration of that.

The textile also features numerous large and small pores that keep the airflow going non-stop. Looking at it through our microscope revealed that its threads are pretty loosely woven.

Being able to forget about sweaty feet is a necessity, not a privilege, and we are happy that Inov8 thinks likewise. The F-Lite Max gets the highest breathability score - 5 out of 5!

The only problem with the shoe's breathable fabric is its fragility. Even though the F-Lite Max features a pretty large toe bumper, we would refrain from using this shoe on abrasive surfaces like concrete.

That's because a single slash or toe drag can damage its upper quite significantly.

The toebox fabric completely failed to resist the sandpaper on our Dremel earning this part of the shoe the lowest durability score of 1 out of 5.

Even though it's not a cheap shoe, the inner lining of the F-Lite Max didn't live up to our durability standards.

Our Dremel burned through the textile in less than 4 seconds lowering the heel padding durability score to the minimum (1 out of 5).

On the bright side, Inov8 chose solid abrasion-resistant rubber for the shoe's outsole.

According to our Shore C durometer measurements, both green and black rubbers showed an identical reading of 86.0 HC which indicates above-average hardness.

Putting the shoe's outsole rubber through our most abrasive durability test (22 seconds at 10K RPM Dremel speed), we were pleased to see that the damage was moderate.

As our tread gauge showed, the newly occurred dent was only 1.2 mm deep which is common for most cross-trainers.

The black rubber also protrudes up on both the lateral and medial sides of the F-Lite Max. It forms protective Rope-Tec wings that guard the shoe from getting burned against the rope during rope climbs.

Hard, abrasion-resistant, and thick, the outsole of the Ino8 F-Lite Max promises a long and happy life.

Our caliper measured its outsole thickness at an above-average reading of 4.1 mm which is plenty of rubber for an indoor gym shoe.

The Inov8 offers the F-Lite Max at the same price as the industry-leading Nike Metcon 9 and the Reebok Nano X4 and we believe it's fair.

If you prioritize a highly stable platform for lifting- and Crossfit-oriented training regimen, this trainer is well worth the cost.

The interiors of the F-Lite Max are rather moderately padded.

Our caliper showed 5.9 mm of foam thickness in the shoe's tongue which is common for training shoes.

Contributing to the shoe's secure foothold is a fully gusseted tongue which made the inner bootie feel like one piece around our foot.

We never had issues with tongue shifting and this tongue design also worked perfectly in tune with the external Met-Cradle to provide side-to-side containment.

There is no pull tab or finger loop to help with the on-and-off.

Even though the insole of the F-Lite Max is easy to remove, not many custom orthotics will accommodate the in-shoe space of this trainer.