Inov8 F-Lite review

The F-Lite deserves to be on your radar if:

• you need a gym shoe with the roomiest possible fit and toebox
• you are after a cross-trainer that can do a bit of everything and is not too specialised
• you want a lightweight and flexible trainer that feels agile

If you lift heavy regularly (your body weight and beyond), it makes sense to opt for the brand's more stable and sturdy option, the F-Lite Max.

And if you want an equally lightweight and flexible trainer but with a more traditional toebox shape and medium width, try the Nike Free Metcon 6.

Like most versatile cross-trainers these days, the Inov8 F-Lite balances between cushioning for cardio (and other high-impact exercises) and stability for weightlifting.

Its shock absorption measurements came in at a moderate 85 SA in the heel and 64 SA in the forefoot, which is typical for most training shoes we've tested. You can expect some essential impact protection for jumps and short runs (up to a mile).

In its product description, Inov8 promises a bouncy experience through the combination of a Powerflow Max midsole and a Boomerang insole. But you can only expect this much rebound from a gym shoe.

Our energy return tests confirmed that the F-Lite has a bit more responsiveness than the category average at 59.1% in the heel and 57.6% in the forefoot. This is not a dull experience for sure, but please note that the propulsion is not as high as in running shoes.

The Inov8 F-Lite also proved to have a moderate stack height of 24.1 mm in the heel. It sits right at the average of training shoes, offering a good buffer from the ground but keeping you close enough to feel planted.

The shoe's forefoot stack also came in at a standard 17.7 mm, keeping the toes sufficiently close to the floor but decently protected from the impact.

We found a significant discrepancy of 2.4 mm between the F-Lite's stated drop (4 mm) and our measured drop (6.4 mm). However, the good news is that this difference is not significant enough to cause discomfort or a sense of an excessively elevated heel.

Even though it doesn't pack the same TPU stabiliser as the Inov8 F-Lite Max, you can expect a firm underfoot experience from the Inov8 F-Lite.

Measuring the shoe's single-density midsole with a durometer, we got a relatively high reading of 30.0 HA. Although it's not brick-like, the compression is minimal here.

If you often struggle with finding a gym shoe that fits wider feet or bunions, Inov8 is the way to go!

Measuring a solid gel mould of the F-Lite's interiors, we recorded as much as 99.6 mm in its widest part! Wider than average, it offers plenty of room in the ball of the foot area, even for those with broader foot dimensions.

But it's also the shoe's toebox shape that makes a huge difference.

With a whopping width of 78.1 mm in the big toe area, it exceeds the average of training shoes quite a bit! And it is, in fact, one of the roomiest cross-trainers on the market.

As if the F-Lite's forefoot isn't broad enough horizontally, it also offers plenty of space vertically! The shoe's toebox height proved to be one of the tallest in our lab at 30.7 mm.

Forget about pinch points or black toenails.

Having measured the Inov8 F-Lite Max's friction coefficient at an impressive 0.53, we were baffled by an unexpectedly low result of 0.21 in the regular F-Lite model. We even performed some additional blind testing to double-check the results and still found the F-Lite less grippy!

Even though both shoes list Inov8 Rubber as their outsole material, the blend is apparently different. We wouldn't say that the F-Lite's lack of traction is dangerous, but we would advise being mindful of slick, wet, and dusty patches.

The Inov8 F-Lite features the same outsole design as most of the brand's other training shoes.

It's a signature mix of a flatter honeycomb treading in the rearfoot (for better ground contact) and large flex grooves in the forefoot (for enhanced flexibility).

Touted as the brand's most flexible cross-trainer, the F-Lite proved to be very pliable indeed!

Measuring the amount of force it takes to bend the shoe by 30 degrees, we recorded a pretty low reading of 8.0N, which makes it bendier than the F-Lite Max.

This makes the shoe much more agreeable for planks, lunges, runs, and jumps, and even for casual walking. 

Staying light and agile on your feet is also made easier thanks to the shoe's below-average weight.

Tipping the scale at 10.5 oz (298g) in a men's US size 9, the F-Lite is a whole 1.6 oz (46g) lighter than the F-Lite Max (in case you are choosing between the two).

At first glance, the shoe's engineered mesh appears to be quite airy. But upon closer examination, it turned out to be only moderately breathable.

Assessing its toebox permeability in our smoke test, for example, we found that the billows it releases are relatively thin compared to shoes like the Nike Free Metcon 6.

But the F-Lite's upper showed some decent transparency in our light test, revealing its ventilation pores in the tongue and midfoot as well.

And as for the shoe's toebox perforations, we found that they are partially blocked by the mesh lining underneath.

All in all, we assessed this shoe's breathability with a moderate score of 3 out of 5. Not ideal for sweaty gyms in summer, but pretty nice for mild weather.

Stability is the primary characteristic that differentiates the F-Lite from the F-Lite Max. If you are someone who regularly lifts heavy weights and strives towards new PRs, the F-Lite Max is the way to go. Its stiff TPU Heel Stabiliser makes the platform stouter to resist compression under heavy loads.

But if you need more of an all-around shoe for both cardio and lifting, the F-Lite packs a good amount of lateral support and stability to keep you surefooted.

This Inov8 trainer features a firm base with tall sidewalls and a firm Met-Cradle around the midfoot to keep the foot securely in place when lifting or performing forceful lateral movements.

Both generate a good deal of torsional rigidity, which doesn't let the shoe twist so easily. Assessing its stiffness level on a 1-5 scale in our manual test, we readily gave the F-Lite a solid score of 4.

But as for the shoe's heel counter, we found that it's not nearly as stiff as in the Nike Metcon 10, for example. We were able to squeeze and fold it very easily in our manual test, resulting in a very low stiffness score of 1 out of 5.

However, thanks to the F-Lite's solid midfoot support, we didn't feel like stability was compromised here. And on a positive note, this Inov8 shoe is not as hard on the Achilles as some other cross-trainers.

Measuring the shoe's midsole dimensions with a digital calliper, we also found that it is moderately broad for its kind.

However, its forefoot still proved to be nice and wide, measuring 112.6 mm in the widest area (echoing the shoe's spacious toebox).

But the shoe's heel showed a much narrower reading of 81.5 mm, proving to be slimmer than the average training shoe.

Although it detracts from the F-Lite's lateral stability in the rearfoot, it trims the shoe's weight down and makes the shoe more versatile and manoeuvrable for cardio work and other agile exercises.

With nothing but exposed mesh on its toebox, the Inov8 F-Lite is not the most abrasion-resistant gym shoe out there.

Applying our Dremel to the material for 12 seconds resulted in a large, glaring hole, lowering the shoe's toebox durability score to the lowest 1 out of 5.

But at least the shoe boasts an extended toe bumper to protect the toes and the tip of the shoe from stubbing on gym equipment.

The textile lining inside the shoe's collar also left us wishing for more, as our Dremel scuffed it up quite easily. This lowered the F-Lite's heel padding durability score to only 2 out of 5.

But when it comes to outsole rubber, Inov8 hardly ever falters. The blend proved to be as hard-wearing as it can be after a rigorous encounter with a Dremel.

Measuring the dent depth at a moderate 0.8 mm, we found the shoe's outsole durability to be very promising.

Its outsole thickness also looks reassuring at 4.0 mm.

Like most other training shoes from Inov8, the F-Lite is reinforced with the ROPE-TEC feature on the sides of the midfoot. As an extension of the shoe's durable outsole, it guards the shoe against abrasion during rope climbs.

We couldn't help but notice how thick and cushy the Boomerang insole is in the brand's training shoes. Even though its stats promise 6 mm of thickness, our own calliper measurements showed even more - 6.9 mm!

In addition to offering comfort, we believe that this insole is also responsible for a good portion of the shoe's energy return. You can see that it's comprised of tiny foam pellets, which compress and decompress easily, similar to Adidas Boost.

If you find the shoe's Boomerang insole overwhelmingly cushy, you can easily remove it. But keep in mind that it could be challenging to find an alternative orthotic given the shoe's exceptionally broad toebox dimensions.

In addition to its well-padded insole, the F-Lite also packs a generously padded tongue. With an above-average thickness of 9.1 mm, your instep gets a cosy hug, which also protects it from any lace bites or pressure.

There is no pull tab to help with getting the shoe on, but a slightly extended heel collar can be handy instead.

A fully-gusseted tongue works together with the Met-Cradle to provide a more secure foothold in the midfoot. It also eliminates the annoying sliding of the tongue.

The Inov8 F-Lite is not a cheap cross-trainer but we believe that it is fairly priced in relation to what it has to offer, especially if you need an extra spacious toebox.