Inov8 F-Fly Review | Fantastic Shoe for HYROX Workouts?

How I’ve Tested These Shoes

For the Inov-8 F-Fly, I’ve made a conscious effort to truly push this shoe in the hybrid vertical. Sure, I train like that normally, but I wanted to really hammer some good runs in this shoe to assess its overall comfort.

Training Tests Summary

• Heaviest Lift In These So Far: Trap Bar Deadlift 455 lb x 6
• Longest Run In These So Far: 5-Miles (7:30 – 8:30 mile pace)
• CrossFit Tests So Far: Open Workout 24.1, Linda
• Total Miles Walked: 30-miles (per the publishing of this review)

Why the F-Fly Surprised Me for Lifting

Of all my tests, the F-Fly’s lifting performance has been the most surprising. Generally, a training shoe marketed as “hybrid” falls short of truly pushing weights in the gym—here’s looking at you On Cloud X 3.

For squats, I’ve trained up to 325 lbs in this F-Fly, and it did a pretty good job. At this weight and above it, you will notice the POWERFLOW PRO midsole compresses a bit, but it never feels unstable or as if I lack balance when training.

Because this shoe has a wider sole and a “lower” stack height compared to other “hybrid” workout shoes, you can push higher intensities in this model without feeling like you’re squatting with normal running shoes.

As for deadlifts, I pushed this shoe’s thresholds up to 455 lbs with a trap bar deadlift of 6, and it felt pretty good. Again, you’ll definitely feel the midsole compress a bit, but not to the point where I was concerned.

For a funny anecdote, I just used the NOBULL DRIVE for the same tests to compare the two since they’re both hybrid shoes, and never again. It’s night and day, and the Inov-8 F-Fly is the clear winner of the lifting tests. The DRIVE felt like I was lifting on pillows.

In the context of general strength workouts, these should work perfectly fine. For example, if you need a model for hitting free weight sessions, some moderate machine work, and hypertrophy sets, you’ll like these.

My Thoughts On Using This Shoe for CrossFit and Cross-Training

For cross-training and CrossFit, I think the Inov-8 F-Fly will work exceptionally well for some workouts but may fall short for others. To elaborate, it really comes down to your weekly training breakdown and what you want these for.

In the realm of cross-training, I found the F-Fly to work best for workouts where I was doing sled work, kettlebell circuits, and explosive exercises like broad jumps and box jumps — think front-to-back explosive exercises and movement.

This shoe can be used for lateral work. However, its downfall is the lack of rigidity around its toe box and lateral midfoot. You may experience some spillover with this shoe if you’re doing harsh cuts and exercises like skater strides.

I also think narrower feet may find that they slide around in this shoe for this performance context. This model doesn’t have the lowest profile upper, and I could definitely see security being an issue for narrower feet in this training context.

For CrossFit, this shoe will slap when you’re running in WODs. It’s stable enough for lighter-weight deadlifts and squat thrusts, and it works well for interval runs, double-unders, and burpee box jumpovers.

Basically, wear these on WODs where you know you’re not rope climbing or going crazy with your strength work. I would not wear these for tackling heavy clean & jerks and snatches, or maxing out/testing my squats and deadlifts.

The Type of Running and Walking I’ve Liked the F-Fly Best For

The reason I like the F-Fly for HYROX-style training is its ability to excel in short runs. Thus far, I’ve run up to 5 miles in this shoe, and where I liked them best was for intervals and 5k runs.

For this running style, I’m primarily using my forefoot to move quickly, and I enjoy the responsiveness of the POWERFLOW PRO midsole in this model. It feels lively and bouncy despite having a more “minimalist” vibe than normal running shoes.

This construction feature will be well-suited to barefoot shoe lovers and those who like lower-stack height running shoes. Even when running slower and with the heel striking a bit, I didn’t find this shoe too uncomfortable, which was also a nice surprise.

Would I use this shoe for tackling marathons and high-volume running weeks? I would personally not, but that’s because I like plusher shoes for this running style, as I feel less beat up from using them when tying together my running and strength workouts.

I’ve thoroughly enjoyed this shoe’s performance and comfort while walking. The outsole has a good level of tread, and it’s comfortable for long walks and being on your feet all day. I wear mine looser to slip on when wearing them for walking.

If you’re like me and like training shoes that you can wear casually and comfortably all day to run errands, walk the dog (or kids!), and even travel with, you’ll appreciate the F-Fly’s comfort.

Construction Details

The construction of the Inov-8 F-Fly is one of my favorite things about this shoe. It’s simple, but it ticks all of the boxes you want from a good hybrid workout shoe.

Outsole

The outsole features a full rubber tread patterning with 2.5mm thick lugs. These lugs did a good job of biting different gym surfaces like turf, rubber gym floors, and even wooden platforms.

Outdoors, when running, I’ve also enjoyed how these lugs have bit concrete, grass, and light gravel. These are all surfaces I’ve encountered with these shoes, running and walking in them.

There’s a meta-flex split at the forefoot, which tends to be standard for Inov-8 shoes, and this gives the outsole a little more flexibility. This model also features ROPE-Tec at the midfoot. If you do end up using this shoe for rope climbs, this feature helps a ton.

Midsole

The POWERFLOW PRO midsole is the star player of this shoe. Inov-8 uses their POWERFLOW midsole in most of their training shoes. For example, the Inov-8 F-Lite 235 V3 and 260 V2 use this midsole but its much denser.

The midsole depth of this shoe is 10mm in the heel and 6mm in the forefoot, giving this shoe a 4mm heel-to-toe drop. Compared to normal running shoes, the F-Fly’s midsole stack height is a lot lower, and this contributes to this shoe’s articulation and flexibility.

There’s a little toe spring in this shoe and heel bevelling. I never found these features to take away from this shoe’s lifting performance because they’re not overly aggressive.

Upper, Tongue, and Laces

The upper is primarily composed of a lightweight mesh. This mesh also features a 3D-printed construction, which helps contribute to this shoe’s durability and support when running and doing explosive workouts.

I like the breathability of this shoe’s upper, and I think the mesh makes it a good pick for hot climates and outdoor workouts. This shoe utilizes five eyelets, with a sixth eyelet for lace-locking.

The tongue is gusseted and built with a padded mesh. I have yet to experience tongue security issues in this shoe, even when wearing it looser. For a hybrid-focused shoe, Inov-8 nailed it with this model’s upper construction.

My Sizing Advice

I think for most lifters and athletes the Inov-8 F-Fly should fit true to size.

This model’s length is a smidge on the shorter side compared to my other size 10 shoes, and they have a wider forefoot width. Size the F-Fly like your other Inov-8 shoes if you own their shoes already.

For context, I wear a size 10 in all of my training shoes. I have an E-width foot with a normal arch. This shoe fits my foot like a glove, and I even have additional room in the forefoot for toe splay.

Additional Sizing Thoughts

• To elaborate, for medium and wider feet (E to EE-widths), you’ll be fine going true to size.
• If you have narrow feet, you may want to look into models that better suit your foot anatomy.
• If you have wide feet and you find you’re normally hitting the end of your toe box, size up a half-size.

If you have additional sizing and fit questions about the Inov-8 F-Fly, drop a comment below, and I can help you out. Let me know what shoe you currently wear and in what size, so I have some context.

Final Verdict

Inov-8 came out swinging the Inov-8 F-Fly. The hybrid shoe market is still what I would call in its infancy stage, or at least that’s how it feels as the hybrid training style continues to get more popular.

If you’re a HYROX athlete, a CrossFitter wanting a more runnable training shoe, or someone tired of using multiple shoes for training and wants a singular model for running and lifting, the Inov-8 F-Fly can be a great choice.

If you have additional questions about this shoe, drop a comment below, and I will help you decide if these are right for you.