Physical Therapists Using Clinical Analysis To Discuss The Art And Science Behind Running and The Stuff We Put On Our Feet

Post Page Advertisement [Top]

361 FIERCE Multiple Tester Review

361 has a decent history with solid simple lightweight trainers. The Spinject was one of the originals, featuring a simple knit upper and a solid, flexible sole (REVIEW). The Fantom was the evolution of the Spinject, gaining a bit of weight but adding a thicker and more secure upper (REVIEW). The Fierce is the next in line. Featuring a similar but guided flexible outsole and an evolved knit upper, this should be a similar shoe right? Well... yes and no.

Specifications (per 361 USA)
Weight: 9.8 oz / 280 g (men's size 9) 8.1 oz  / 229 g (women's size 8)
Stack Height: 23.5 mm / 15.5 mm
Drop: 8 mm drop
Classification: Lightweight Trainer


Matt: The 361 Fierce is a flexible, narrow fitting, lightweight trainer following the footsteps of the Fantom and Spinject. Featuring a narrow engineered knit upper and a QU!KSPRING+ midsole (modified EVA), this newer trainer takes some time to break in. While a slight heel bevel has been added, the ride is a bit stiff initially. The upper fits narrow in the toe box and although it opens a little with several miles of use, will work better for those wanting a narrow and snug fit. While the flex groove placement makes for some interesting mild guidance, this shoe is fairly traditional. The 361 Fierce is best for those looking for an narrow and slightly firmer ride for the recreational or beginning runner wanting to perform easy or uptempo efforts in a less structured shoe.

I think that the best way to describe this shoe is a simple, flexible, and firm trainer. The QU!CKSPRING+ midsole is quite firm back to front, but the flex grooves throughout the midsole and beveled heel give a lot of flexibility and overall smooth ride. My hot take is that FIERCE really isn't that fierce, but more of a daily runner with a more narrow fit and nice feeling upper. 

David: The 361 FIERCE is a firmly riding flexible daily trainer. There are not much bells or whistles to this shoe. It is pretty close to the ground with flexibility and a semi natural feel. The upper is narrow throughout but the knit is done pretty well. The name seems to be a misnomer, for this shoe is not that fierce. A neutral, flexible, firm trainer.


Matt: The 361 Fierce fits true to size length wise in my normal men's size 10. The fit is very narrow in the forefoot with a fairly tapered toe box. This does open up a little after a few miles, but the fit especially up front is narrow. The midfoot and heel are average width and should fit fine. The tongue is somewhat thin and despite being free floating is fairly secure. The laces are thin, smooth and unfortunately do not hold well. I have had the right shoe come undone multiple times even when double knotting. This occurs especially with uptempo efforts, so make sure you really secure those laces.

Despite the lace issue, I have had zero problems with heel slippage, even when they do come undone! The upper is a knit material that has additional reinforcement wear it connects to the sole. It is fairly breathable and does slowly mold to the foot with time. The heel counter in this shoe is fairly rigid and aggressive. The heel collar has some decent cushioning, so the hardness is offset a little. It does extend fairly far forward into the midfoot, so there is some guidance there. Overall the upper and fit will be best for those with narrow feet or looking for a bit more of a performance fit.

Nathan: The FIERCE stays true to many other 361 shoes in that is is a bit narrow in the forefoot, particularly on the lateral aspect of the toe box. Additionally it seems to fit a bit long, but not enough to want to go a half size down for length (especially given the narrow lateral side of the toe box). The last small issue I had with the fit is the laces, which come undone if not double knotted. Other than that, there is actually a lot that I like about the fit. The upper is a refined knit upper that stretches a bit over the first few miles, which helps with the narrow toe box. The midfoot feels secure even after the bit of stretch and I don't have any heel slippage.

     361 consistently makes my favorite tongues as they sit in the sweet spot between thick and thin, and despite not being gusseted it has not slipped around at all. The heel cup is of moderate width and has nice padding and a little retrocurve at the top that serves as a nice pull tab. Additionally, the rigid heel cup extends all the way to the midfoot on each side, but is padded well and does not irritate the foot at all. All in all, this is a great fit with a comfortable upper for my moderate to narrow foot. The main improvement for me would be decreasing the length just a bit.

     Step in comfort is the last part I wanted to touch on. Inside the shoe there is a thin topsole and sock liner that provides mild cushion. However, the amount of cushion is so thin that I immediately felt my heel go through the liner and onto the firmer foam below. The shoe felt better once I got moving and after putting some miles on...more on that below.

David: The upper is my favorite part of the FIERCE. The knit upper accomodates the foot pretty well for being narrow initially throughout. The lockdown with the laces could be a little bit better but I did not have any excessive translation anywhere. The hold on the midfoot is pretty decent and has a natural curvature to it that seems to cup and hold the navicular region pretty well. The knit is of decent thickness. It is thick enough to keep your feet warm, but not to overheat. It is not the type of knit that feels like a sock upper, but still a comfortable and consistent upper through varying conditions. The tongue holds the dorsum of the foot nicely as well and compliments an all together pretty solid upper. The toe box is normal to slightly wide and has enough space for toe splay and swelling as well. 


Matt: The 361 Fierce has a fairly flexible and firmer ride. There are flex grooves throughout the length of the shoe that provide a subtle but guided ride forward. The forefoot and midfoot are especially flexible, making for a great mid and forefoot transition. The heel is fairly firm and clunky. Landing at the rearfoot is a bit shocking at first until both you and the shoe warm up. There is a heel bevel, but it is fairly small and steep.     

     The ride overall is a bit more firm. This feels good when picking up the pace and landing farther forward, but not great during slower paces. The Fierce is best for normal runs and  uptempo efforts. I have used this shoe for daily runs, fartleks and hill repeats. The QUI!KSPRING+ responds decently to picking up the pace, but is certainly not bouncy. I would describe the ride as more consistent, as I know what to expect at the beginning and end of a workout. Once you warm up and start landing a bit farther forward, the ride is decent. However it is firm enough that I did not enjoy it during long runs. As you fatigue, the clunky heel becomes more apparent. So for me this shoe maxes out at 7-8 mile runs.

     The outsole, like many 361 shoes, is fairly durable.  After 35 miles the rubber patches are doing fine, but I am getting a little more wear at the exposed midsole. It is very mild and I would expect a solid number of miles out of these for a lightweight trainer. The flex grooves are very good in the midfoot and forefoot, however they are rock magnets. This is not a shoe I would take on rocky trails as I have gotten all kinds of debris stuck in there. So those looking for a simple road shoe for middle distance mileage who land farther forward and also want to do some uptempo work will enjoy this shoe.

Nathan: This shoe falls into the category of flexible, no frills trainers in terms of the ride. Before I dive in, I must state that my take is skewed because I very much enjoy a firmer feel underneath for daily miles. Enter the FIERCE, one of the most firm shoes I've tested in the last several years -- even more firm than the previous iterations of this shoe (Fantom and Spinject). 

    Besides being firm, here is a bit about the ride and how it's influenced by the foam. The heel does have a bevel, which helps smoothen out heel strike for those of us who land back there. That said, because of how firm the foam is, the heel can still be clunky at heel strike. Moving forward, the flexible design of the outsole with the abundance of flex grooves allows for a smooth transition all the way to the forefoot. The flexibility continues to the forefoot, but the firmer foam does provide a slight snap to toe off. This shoe is not responsive or bouncy at all, but you still will get a daily trainer that is consistent and gives nice transitions. 

     The outsole has rubber in the landing zone and push off with exposed EVA in between. Even in the snow, I've had decent traction despite the lack of rubber. This is likely due to the many flex grooves that have gripped the snow. The one issue with the flex grooves is that they are magnets for rocks. I do many miles on a crushed gravel path, and those sized rocks filled the flex grooves after runs. As for utility, I found this shoe best for my daily miles for shorter and mid distance runs.

David: The ride of the 361 is pretty firm and flexible. The EVA is exposed for the majority of the midsole/outsole except for the high abrasion areas in the heel and forefoot. There are deep flex grooves that help with making this rigid and firm foam have some give to it throughout. The ride itself is not overly impressive with responsiveness for it is more of a natural firm riding feel. The shoe feels best at normal training and easy paces. My hot take on the ride actually feels more like a lifestyle shoe that can run rather than a daily trainer that can double as a lifestyle shoe. The heel transition could be a little smoother with the bevel angle and midfoot transition. The midfoot to toe off is pretty smooth overall. The ride feels like a firmer riding and slightly more flexible FANTOM. 


Matt: The 361 Fierce is a neutral trainer. However, there are several elements that add mild stability to the upper and platform. The heel counter runs fairly far forward into the midfoot, providing mild guidance both medially and laterally. The flex grooves in the sole also provide very gentle guidance and facilitated flexibility throughout the length of the shoe. There is also subtle sole flare both medially and laterally in the forefoot and heel, providing a little structure to the ride.

Nathan: The geometric design of this trainer might be my favorite part. There are well placed medial and lateral flares throughout the shoe to create a wider contact platform. This, combined with a firmer platform makes this shoe quite stable for a shoe that is so flexible. The only areas with a bit of potential instability are the heel due to the starker contact due to the firmer midsole and the upper as the knit design stretches. For the latter, this can easily be combated with adequate lacing, but as the miles got put on I did need to lace down more aggressively to achieve the same lockdown.  So for those that need just a bit of structure without posting or more traditional means, the Fierce should perform decently.

David: The 361 FIERCE is not a formal stability shoe and therefore does not have any formal stability measures. The shoe overall is flexible throughout and that will reduce the stability, but still rides pretty low to the ground and is firm riding. Because of this the shoe will ride more stable than it initially seems. The upper is constructed pretty well and is pretty sturdy for a knit upper. It can handle most forces and does well with turns. The stability is pretty good for a flexible shoe, but again nothing to rave about necessarily.   


How does the amount of cushioning affect biomechanics and loading rates?

     We thought this would be a good chance to talk about the influence of different levels of underfoot cushion (stack) on the biomechanics of running given the firmer nature of this shoe. One of the theoretical goals of cushioning is to help with shock absorption as we land. The utility of foam to be able to help with shock absorption is not well established yet. However, it is well understood how the body itself absorbs shock. 

     The quick and dirty of how the body absorbs shock is through movement of the joints as we land. When your foot hits the ground (if you land on your heel) your knee and hip start to bend. If your knee goes through 40 degrees of knee bend, the quadriceps helps provide more shock absorption than if your knee only went through 20 degrees of motion. Likewise in the hip. The more motion that the hip goes through as you land, the more shock absorption your gluteal and hamstrings provide to the body. If there is not a lot of shock absorption through the muscles, it has to be elsewhere, which means that more impact and shock is absorbed through the joints and bones. Long periods of inadequate shock absorption (which is individualized) can lean to certain injuries related to bone and joint health such as stress fractures. 

     A 2018 study by Kulmala et al. looked at the influence of highly cushioned shoes on impact loading. This is obviously of high interest given the recent surge of maximalist-type shoes. What this study found was quite interesting. In comparison to a conventional running shoe (Brooks Ghost 6), the highly cushioned shoe (HOKA Conquest) resulted in higher impact loading rates at both slow (6.4% increase) and fast (12.3% increase) paces. What is interesting is that common sense would say that impact loading would decrease with more cushion, but this study showed the opposite effect. Assessment of these results shows that this increase in loading rates was due to stiffening of the joints. The effects of a stiffer joint when landing is shown above. Now, this doesn't mean that running in a highly cushioned shoe is going to cause impact related injuries, it just helps explain why we haven't seen a dramatic drop in injury rates since the advent of these shoes. 

     One of the thoughts is that a highly cushioned shoe is more inherently unstable (like trying to balance on one foot on a soft pillow versus on the ground) and therefore our body responds by stiffening the joints to create a more stable movement pattern. Less motion is easier to control than more motion. Therefore, a more firm platform like in the FIERCE may allow a person to move through adequate joint motion to achieve shock absorption through our muscles. This difference in impact loading and joint excursion may not be significant in terms of injury for everyone, but for certain patient populations that we see in the clinic, it can become a consideration for their particular case to provide a platform that allows for increased muscular shock absorption.

-Nathan Brown PT, DPT, MS

Kulmala, J. P., Kosonen, J., Nurminen, J., & Avela, J. (2018). Running in highly cushioned shoes increases leg stiffness and amplifies impact loading. Scientific Reports8(1), 1-7.


Matt: The Fierce has a great deal of potential. However there are several changes that need to occur. The first is to restructure the heel. Despite the addition of a mild heel bevel, heel landings are pretty rough until the shoe breaks in each run. I'd suggest either a decoupled heel or add a more progressive and significant bevel. The second is that the Fierce is very firm, so softening the ride might make this more accessible to a larger population. Like Nathan, I like firmer shoes. However I think modifying the durometer of the midsole may help make this shoe less aggressive while also providing a bit more bounce.

The toe box also needs some work. 361 typically has a fairly tapered toe box that takes a while to break in, but the Spinject and Fantom have always done a better job. The Fierce fits like many other models, i.e. way too tapered in the toe box. This is likely going to scare people away as initial impressions fit wise are not positive unless you have a narrow foot. I highly suggest modifying this and adding a bit more anatomic fit up front (not Altra, but better than what it currently is). This, like the other suggestions will make this a shoe that will reach a farther audience. Right now people need to know that this shoe takes some time to break in.

There are a couple tweaks that I think could make great improvements to the shoe. First is somehow softening the ride. Even being someone who loves a firmer ride, this is just a bit too firm. This could  be done through a softer topsole later that could be added or to increase the softness of the entire midsole compound. Second is decreasing the taper on the lateral toe box for a better anatomical fit of the foot and maybe shortening the shoe just a touch. A final small change would be getting some laces that stay tied a bit better...but I can do that on my end as well.

David: The 361 FIERCE has a lot of potential. I will be honest. After enjoying the FANTOM a lot... I was a little disappointed in the FIERCE. The upper is really nice and I like that, but the midsole and responsiveness of the shoe comes off as a little flat. The QU!KSPRING+ midsole was more responsive in the PACER ST and the STRATA 4 for me. I am not sure if it is a durometer thing but I think the shoe can be softened slightly. The exposed midsole and high abrasion rubber pieces are ok. I think the foam needs to be updated to allow for more protection and/or more responsiveness. The shoe seems to be a little flat in both categories but would improve a lot if it ventured into either one more. I also agree with Matt with the heel bevel. The heel transition can definitely be refined to make a more pleasant experience with initial contact. From midfoot to forefoot I am pretty happy with. 


Matt: The 361 Fierce is a simple, narrow fitting, firmer, flexible trainer with a surprisingly stable platform. For those looking for a daily trainer that has a little versatility for uptempo work, this is a good option. The entry level or high school runner looking for a durable shoe should also take a look at this model. Those who land a little farther forward, have narrow feet and want a firmer ride should take a look at this shoe.

The 361 FIERCE is a no-frills, firmer, and flexible trainer that has an overall stable platform for a neutral shoe. This shoe may be a great option for people looking for a daily runner and entry shoe for newer runners. If you appreciate a firmer shoe and don't desire bounce or too much of a cushioned feel, this could be an option for you.

David: The 361 FIERCE is a firm riding shoe for those that like a natural and flexible trainer. The platform itself is decently stable for a flexible construction. The shoe is neutral through and through with a midsole that is best at daily and easy paces. The foam isn't overly responsive and the durometer is quite firm. The knit upper is pleasant throughout with decent lockdown. 


Fit: C (Tapered toe box and laces that won't stay tied. Knit design is nice and the extended heel counter does provide additional stability. Best for those with narrow feet)                     
Performance: B- (Extremely clunky heel but smooth forefoot. ) 
Stability: A- (Stable ride for a neutral shoe. Guided flexibility from flex grooves and extended heel counter provide subtle guidance) 
DPT/Footwear Science: B (Guided flex grooves is great along with extended heel counter. However tapered toe box is likely to cause problems for many people and is not optimal for forefoot health. Heel is too rigid and heel bevel needs to be restructured) 
Personal:  C- (I really want to like this shoe, but it is a big step back from the Fantom and Spinject. There is potential here but not enough to keep in my rotation) 
Overall: C+ (The 361 Fierce has great potential as a simple lighter trainer. It will work well for those who want a firmer ride, a narrower fit and who land farther forward)              

Fit: (Very comfortable upper, but a bit too narrow in the toe box and fits a bit long)                     
Performance:  B- (Runs well for those who like something firm (very firm), but a bit clunky at the heel due to how firm the foam is, the insole flattens out quite early from a comfort perspective) 
Stability: A- (For a neutral shoe, the wider outsole contact and firmer platform are stable, upper loosening is only issue here) 
DPT/Footwear Science: (There are benefits of a firmer surface and the stability integration is good, fit just off, loosening of upper changes stability over time if you don't adjust, and heel strike is a bit clunky) 
Personal: B+ (I really enjoy firmer shoes and enjoyed this for daily miles, but didn't have enough versatility and was too firm for a higher grade and all around trainer)     
Overall:  (A nice simple trainer from 361 especially for those who like a firmer ride, just off on the fit and a bit too firm and lack of underfoot comfort/cushion)   

Fit: (The shoe does run a tad long, otherwise the upper fits well, the knit is comfortable and reinforced well)                    
Performance:  C+ (The shoe feels like it needs to choose a side. The shoe is flexible and natural, but the shoe is definitely firm riding to where it might be too firm, and also unresponsive enough to wear I don't want to push it. Overall it is "meh") 
Stability: (Overall pretty stable for such a flexible shoe. The shoe does still have some deformation to unstable ground but the shoe does a pretty good job for such an unstable design) 
DPT/Footwear Science: C+ (There are elements with potential, but execution misses the mark for me. The flexible firm riding shoe could do really well, but the midsole needs to either be more responsive or more protective. The heel mechanics can also be improved as well to reduce clunkiness) 
Personal: C+ (This isn't a bad shoe, but its not a great shoe. I used the word "meh" earlier and I feel that's the best way to describe this shoe. A LOT of potential, but pretty underwhelming with responsiveness or protection. The heel mechanics don't feel that smooth. Otherwise the upper and the midfoot/forefoot are pretty nice.)     
Overall:  C+ (A shoe with SO MUCH potential to be in the likes of Kinvara or Nimbus Lite but just misses the mark with responsiveness and/or protection. The shoe mechanics also need to be refined at the rearfoot. Overall the shoe still is a pretty decent shoe though for the firm riding neutral category) 


Reebok Floatride Energy 3.0 - Soft and affordable daily trainer from Reebok
Saucony Freedom 4 - Light and energetic daily trainer from Saucony
Saucony Kinvara 12 - Classic lightweight trainer from Saucony goes back to its roots for '21.
Asics EvoRide 2 - Impressive update merging aggressive toe spring with a daily trainer platform

Recently at Doctors of Running
Podcast Ep. 38: What is a Carbon Fiber Suspension Shoe, with Inventor Lenn Hann

North Face Vectiv Infinite Review - New ultra distance trail runner
February Round Up: Latest Articles and More at Doctors of Running
Asics GlideRide 2 - Mile crusher with decent cushioning and Guidesole technology
Podcast Ep. 37: Sharing Our Favorite Race Day Memories
On Cloudventure Peak - Lightweight trail racer with expert grip

Thanks for reading!

Dr. Matthew Klein is a 140 lb male with notable PRs of 14:45 for 5k and 2:32:44 for the full marathon.  He typically runs 70-100 miles per week and trains at a variety of paces from 8min per mile recovery runs to 4:40 per mile 1k repeats.  He prefers firmer and responsive shoes with snug heels and medium to wide toe boxes.  He is particular to less cushioned shoes and close to the ground shoes, but can handle a little cushion when he gets beat up. IG handle @kleinrunsdpt

Dr. David Salas is a 135 lb male with notable PRs ranging from 3:54 in the 1500m to 1:08:36 for half marathon. He typically runs 60 to 70 miles per week and trains from about 7:30 recovery runs to fast shorter efforts at 4:30 pace. He normally prefers neutral shoes with a firmer ride, but is completely open to other types of shoes.  He is a footwear enthusiast at heart and will always appreciate a high quality shoe when it comes around. For updates on training or testing, IG handle: @docsofrundavid

Dr. Brown is a 155 lb male with notable PRs of 18:18 5K, 39:25 10K, 1:29:01 half marathon, and 3:54 marathon. He typically runs between 20-40 miles per week at a variety of paces from 7:30-8:30 min/mile for recovery runs to 6-6:45 min/mile for tempo runs. He typically prefers shoes that provide some cushioning underfoot but still maintain a more firm and responsive feel. Current goals for 2020 are to break the 1.5 hour half marathon and 3:30 marathon. IG handle: @nate.docsofrunning

Editor's Note: As always, the views presented on this website belong to myself or the selected few who contribute to these posts. This website should not and does not serve as a replacement for seeking medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist. If you are in the Los Angeles area, I am currently taking clients for running evaluations.

Doctor of Physical Therapy
Board Certified Orthopedic Clinical Specialist
Fellow of the American Academy of Orthopedic Manual Physical Therapists

Nathan Brown PT DPT MS
Doctor of Physical Therapy 
Masters in Anatomy and Clinical Health Science
Movement Performance Institute Certified in Advanced Functional Biomechanics 

David Salas PT DPT CSCS
Doctor of Physical Therapy
Certified Strength and Conditioning Specialist

Bach Pham MS
Marketing and Social Media Manager
Master of Arts in Cultural Anthropology

***Disclaimer: These shoes were provided free of charge in exchange for a review.  We thank the  people at 361 USA for sending us a pair.  This in no way affected the honesty of this review. We systematically put each type of shoe through certain runs prior to review. For trainers and performance trainers, we take them on daily runs, workouts, recovery runs and a long run prior to review (often accumulating anywhere from 20-50 miles in the process). For racing flats we ensure that we have completed intervals, a tempo or steady state run run as well as a warm up and cool down in each pair prior to review. This systematic process is to ensure that we have experience with each shoe in a large variety of conditions to provide expansive and thorough reviews for the public and for companies. Our views are based on our extensive history in the footwear industry and years testing and developing footwear. If you are a footwear rep looking for footwear reviews or consultations on development, we are currently looking to partner with companies to assist, discuss and promote footwear models. Partnership will not affect the honesty of our reviews.

Like and Follow Doctors of Running
Facebook: Doctors of Running Youtube Channel: Doctors of Running 

Please feel free to reach out, comment and ask questions!

Bottom Ad [Post Page]

// ]]>