The Asics 33-DFA is a shoe with huge promise. This is part of Asics move into "natural running", and the '33' in the name is due to the 33 bones in the foot. There are a number of technologies that are aimed at promoting natural foot movement, and I'm happy to see Asics become aware of the move away from intrusive footwear. However, I'd rather see a simpler shoe without these technologies and the weight they incur. Which is really the Achilles' heel of the 33-DFA; it's too heavy. The 33-DFA comes in several ounces heavier than its competition, and for some reason actually feels heavier than it actually is. I've found myself weighing the 33-DFA several times because of this strange sense of being overly dense. I've rated the 33-DFA 3 as "worth considering", as it's a big improvement over shoes like the Asics GT 2000, but there are better shoes you should look at. (I use The Science of Running Shoes as the basis of how I test running shoes and what you should look for in a running shoe.)

Asics 33-DFA top	Asics 33-DFA bottom. Notice the deep 'X' grove that is Asics 'Deep FluidAxis' that gives the 33-DFA its name.
Asics 33-DFA inside. Looking at the midsole, the white foam is denser than the dark gray foam that is above it.	Asics 33-DFA outside

1 Characteristics

Why you’d buy it. The main issue with the 33-DFA 3 its weight. I think the 33-DFA is worth considering, but I would avoid racing in it. As a training shoe, there might be benefits to the extra weight; rather like running in the Asics Gel Hyper Speed while wearing ankle weights ;}
Cushioning . The 33-DFA is reasonably well cushioned, but I'd expect more given its weight. The 33-DFA seems rather like it's made of overly dense foam, as I'm always surprised by its weight when I pick it up. It's actually the same weight as the Altra Instinct, but for some reason it feels heavier. I find the cushioning is smooth and even, and it would be fine if the shoe were a few ounces lighter. I found the 33-DFA didn't have quite as much rebound/bounce/spring as the Saucony Kinvara.
Drop. The 33-DFA is zero drop, which is great, especially from a major manufacturer. I love seeing low and zero drop become mainstream like this. However, I'm surprised the 33-DFA doesn't have better forefoot cushioning. Most low drop shoes have similar cushioning levels at either end, but the 33-DFA is quite a bit less cushioned in the front.
Structure. The 33-DFA uses two densities of foam, but it doesn't attempt to manipulate or interfere with your natural biomechanics as many dual density shoes do. Instead of putting the firmer foam on the inside of the heel to try to prevent foot pronation, the 33-DFA puts the denser foam under a layer of softer foam. In the pictures above, the dense foam is white and the dense foam a dark gray. The 'DFA' stands for 'Deep FluidAxis', where FluidAxis is the X shaped gap in the foam you can see in the pictures of the underside of the shoe. This X is intended to make the shoe flexible in the two axis of the X, again encouraging the natural movement of the ankle. Does it work? I couldn't tell any difference, but this type of technology can exert a subtle influence over many miles without you being aware of it. I can't say if it's good or bad, but at least the intention seems more reasonable than many shoe technologies I come across.
Flexibility. The 33-DFA has good flexibility, something that's helped by the gaps in the forefoot outsole and the groves in the midsole.
Outsole. There's a good layer of harder rubber outsole over the contact surfaces, giving the 33-DFA good wear characteristics. I found that the X shaped gap in the midsole did tend to act as a stone trap, though the position of the stones meant this did not cause me any major problems.
Shape. The Altra 33-DFA is intended to "mimic the shape of the human foot", and "allow the toes to splay", but sadly it doesn't. While Asics Natural33 Last might be slightly better than other Asics shoes, it's still not designed to fit the human foot, and I had to cut open the toe box for my feet to move naturally. This is common to pretty much all running shoes, but it's a particular shame in a shoe that is intended to be more natural. (I recommend cutting open the toe box of virtually all running shoes, with the exception of a few shoes like some Altra shoes. When you have some worn out shoes, you should try cutting open the toe box. I've found that it's a big improvement, allowing my toes to move naturally and engage for toe off, as well as reducing the possibility of blisters.)
Upper. The upper is unpadded in the forefoot, but has a small amount of padding in the rear. The material is a little thicker than I'd like for breathability, but no worse than most shoes. There are reinforcement overlays, but no seams, and the overlays are positioned so they're unlikely to cause issues. The ankle opening is nicely padded.
Tongue. The 33-DFA has a traditional tongue that is has a tab to attach it to the laces, and it's moderately padded.
Lacing. The laces are slightly rounded, but they stayed tied.
Heel Counter. The 33-DFA has no heel counter, which is another nice feature. I believe heel counters are useless at best, and the 33-DFA shows how little a shoe needs one.

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This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions.

2 Comparisons

Here are some direct comparisons with its potential competition.

2.1 Altra 33-DFA‏ and Asics Gel Hyper Speed

The Asics Gel Hyper Speed provides about the same cushioning as the 33-DFA, but weighs 4.7oz less, which is a huge difference. This makes the Hyper Speed a far better shoe than the 33-DFA, though I like the zero drop nature of the 33-DFA, it's not enough to compensate for the weight.

Asics 33-DFA top	Asics 33-DFA bottom	Asics 33-DFA inside	Asics 33-DFA outside
Asics Gel Hyper Speed 6 top	Asics Gel Hyper Speed 6 bottom	Asics Gel Hyper Speed 6 inside	Asics Gel Hyper Speed 6 outside

Please support this site

This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions.

2.2 Altra 33-DFA‏ and Hoka Clifton

The Hoka Clifton is a wonderful shoe and the 33-DFA really can't compete. The Clifton has massively more cushioning, but lighter than the 33-DFA. While Asics claim their AmpliFoam midsole "provides soft cushioning constructed at a lower density", it doesn't come close to the Hoka foam.

Asics 33-DFA top	Asics 33-DFA bottom	Asics 33-DFA inside	Asics 33-DFA outside
Hoka Clifton 2 top	Hoka Clifton 2 bottom	Hoka Clifton 2 inside	Hoka Clifton 2 outside

Please support this site

This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions.

2.3 Altra 33-DFA‏ and Saucony Kinvara

The Saucony Kinvara is one of the most popular and best transitional shoes, and is an obvious competitor for the 33-DFA. The Asics is zero drop while the Saucony has just 3mm, but counterintuitively it's the Saucony that has similar cushioning in the forefoot and heel. While both shoes have about the same cushioning at the heel, the Saucony is much better in the forefoot. Yet again we see the 33-DFA coming in too heavy against its competition; the Kinvara is 2oz lighter. That could be more than a minute off your marathon time.

Asics 33-DFA top	Asics 33-DFA bottom	Asics 33-DFA inside	Asics 33-DFA outside
Saucony Kinvara 6 top	Saucony Kinvara 6 outside	Saucony Kinvara 6 bottom	Saucony Kinvara 6 inside

Please support this site

This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions.

2.4 Asics 33-DFA and Asics GT 2000

I tend to compare shoes against my benchmark "normal running shoe", the Asics GT 2000. Perhaps here we can find the shoe that Asics was thinking they were improving on. The GT 2000 is heavier than the 33-DFA, and a lot less cushioned in the heel. The GT 2000 includes structures that attempt to interfere with your biomechanics rather than encourage natural foot movement. At least in the company of the GT 2000 it looks like a huge leap forward.

Asics 33-DFA top	Asics 33-DFA bottom	Asics 33-DFA inside	Asics 33-DFA outside
Asics GT2000 top	Asics GT2000 bottom	Asics GT2000 inside	Asics GT2000 outside

3 Cushioning and Shoes

It's intuitively obvious that the cushioning in a shoe will reduce the impact on your body when running. However, The Science of Running Shoes indicates that the reality is rather more complex. While slight cushioning may reduce the effort needed to run by improving your Running Economy, most scientific research indicates that more cushioning does further improve Running Economy. In addition, cushioning does not generally reduce impact and may actually increase it. This is counterintuitive, but is likely to be due to the way a runners mind and body adapts to softer cushioning. Unfortunately, the scientific evidence is far from complete and it's hard to give clear recommendations. I believe that some runners will prefer more cushioning, while others prefer less, and typically those running further have a fondness for greater cushioning. I also believe that a shoe should be as light as possible, and a shoe should justify its weight with the cushioning it provides. My advice is to decide what level of cushioning you're looking for, and then find the lightest shoes that also fit well and are comfortable.

4 Visualizing the Attributes of the Asics 33-DFA

How Asics 33-DFA compares showing rearfoot cushioning against the performance penalty of its weight. Upper right is better.	How Asics 33-DFA compares showing forefoot cushioning against the performance penalty of its weight. Upper right is better.
How Asics 33-DFA compares showing the price against the benefit (cushioning/performance penalty). Upper left is better.	How Asics 33-DFA compares showing the loaded drop against the benefit (cushioning/performance penalty). Upper left is better.

5 A Comparison with other Recommended Shoes

If you're looking for "the best of the best" running shoe, here are my top picks. Of course, the answer will depend a little on what you're looking for, so I have recommendations for various categories.

Best All Round Shoe. The Altra Escalante is my current all-round favorite. It has plenty of cushioning for its weight, it has a very springy midsole, it lasts well, and it has a shape that's closer to the shape of a human foot than most shoes. It's a great shoe for any runner, including those Starting to run. It's also a fairly easy shoe to find due to its popularity.
Best Maximalist Shoe: If you want something massively cushioned, then I'd recommend the Saucony Kinvara 8. It's remarkably light and remarkably cushioned, beating Hoka at their own game.
Best Optimal Shoe: For those looking to trade cushioning for speed, the Nike Zoom Streak LT 3 was my top pick, but the latest version (LT 4) falls short of it's predecessor. There are lots of great optimal running shoes, which provide just enough cushioning with light weight and minimal frills, but all have their weak spots. Probably the best option at the moment is the Altra Vanish-R, which offers great cushioning for just over 5oz/150g.
Fastest Shoe: If you really want speed, then check out the Nike Vaporfly 4%. It's light, massively cushioned, and has a carbon fiber plate. Nothing comes close, not even the now defunct New Balance RC5000‏‎ or New Balance RC5000v2‏‎. There are a number of caveats; it's really expensive, it's really hard to find, and there's a significant injury risk.
Best Minimalist Shoe: Merrell Trail Glove. I recommend the trail glove for road running in spite of the 'trail' moniker. It's not a fast shoe by any means, but it's comfortable and will last well.
All Terrain Shoe. For trail running, I've become a fan of Altra, and I think their best shoe is the the Altra Timp, though the Altra Lone Peak is really close.
Honorable Mention: It's not really a running shoe, but the Vivobarefoot Ra is comfortable, minimalist and can more or less pass as a dress shoe. I've worn mine to weddings with a suit and they've not looked out of place. You can run in the Ra, but the leather means it doesn't breathe well.

For a more detailed on running shoes see the Recommendations for Best Running Shoes. This table lists the key attributes of What to Look for in Running Shoes. For more detailed information, on the shoes see detailed shoe comparison.

Full Review	Brand	Name	Rating	Recommended price	Benefit	Weight (oz)	Penalty (sec/mile)	Forefoot Thickness	Heel Thickness	Loaded Drop mm	Cushioning	Flexibility
Saucony Type A Review	Saucony	A/A7	Recommended	$100	6.4	6.7	12.1	19	22	1	4.3	7
Saucony Type A6 Review	Saucony	A6	Highly Recommended	$100	8.2	6.1	9.5	17	21	4	5.0	7
Saucony Type A8 Review	Saucony	A8	Highly Recommended	$90	7.5	6.2	9.7	19	20	-1	4.7	7
Adidas Adios Boost 2 Review	Adidas	Adios	Worth considering	$140	4.7	8.6	13.4	17	27	11	4.0	6
Hoka Bondi 5 Review	Hoka	Bondi	Recommended	$150	6.1	11.6	18.1	38	42	5	7.1	2
Hoka Clayton 2 Review	Hoka	Clayton2	Highly Recommended	$150	9.1	8.3	12.9	23	28	1	7.5	5
Hoka Clifton 4 Review	Hoka	Clifton4	Worth considering	$130	7.7	9.3	14.5	30	35	10	7.2	3
ON Cloudflash Review	On Cloud	Cloudflash	Worth considering	$180	4.4	8.3	14.6	19	26	7	3.7	6
On Cloudracer Review	On Cloud	Cloudracer	Worth considering	$130	5.7	8.2	12.8	19	27	5	4.7	7
ON Cloud X Review	On Cloud	CloudX	Not recommended	$140	4.5	8.3	16.3	21	27	7	3.8	7
Mizuno Wave Cruise Review	Mizuno	Cruise	Worth considering	$120	6.6	5.9	12.5	17	20	7	3.9	6
Newton Distance IV Review	Newton	Distance	Worth considering	$155	7.5	9.1	14.2	26	31	3	6.8	5
Asics Gel DS Racer 10 Review	Asics	DS Racer	Worth considering	$110	8.2	7.0	10.9	21	26	6	5.8	5
Altra Duo Review	Altra	Duo	Recommended	$130	6.0	8.4	13.1	29	29	1	5.0	5
Mizuno Wave Ekiden 8 Review	Mizuno	Ekiden	Worth considering	$115	5.7	5.7	14.6	13	18	6	3.2	8
Saucony Endorphin 2 Review	Saucony	Endorphin 2	Worth considering	$115	8.0	5.1	9.6	15	13	-1	4.1	8
Adidas Energy Boost Review	Adidas	Energy	Worth considering	$160	7.2	10.0	15.6	20	30	7	7.2	5
Altra Escalante Review	Altra	Escalante	Best of the Best	$130	9.1	8.7	13.5	28	25	-1	7.9	6
Altra Escalante 1.5 Review	Altra	Escalante 1.5	Best of the Best	$130	8.2	9.0	14.0	26	27	-1	7.4	7
Saucony Fastwitch Review	Saucony	Fastwitch	Highly Recommended	$90	9.5	7.1	11.1	20	22	4	6.8	7
Topo Fli-Lyte 2 Review	Topo	Fli-Lyte2	Highly Recommended	$100	6.7	9.1	14.2	24	26	3	6.1	5
Reebok Floatride Run Review	Reebok	Floatride	Worth considering	$150	7.7	9.6	14.9	28	34	10	7.4	5
Saucony Freedom Review	Saucony	Freedom	Recommended	$160	5.4	10.7	16.6	25	29	3	5.8	6
Skechers GORun 4 Review	Skechers	GORun	Not recommended	$100	6.1	7.5	11.7	15	23	3	4.5	7
Skechers GOrun Ultra 2 Review	Skechers	GRU	Worth considering	$90	7.5	10.0	15.6	28	34	8	7.5	4
Asics GT 2000 Review	Asics	GT 2000	Not recommended	$120	4.8	11.2	17.4	28	35	5	5.4	2
New Balance Hanzo S Review	New Balance	Hanzo	Worth considering	$110	7.6	6.9	10.7	21	19	2	5.2	5
Hoka Hupana Review	Hoka	Hupana	Recommended	$115	6.1	8.9	13.9	31	36	7	5.4	4
Asics Gel Hyper Speed 7 Review	Asics	Hyper Speed	Highly Recommended	$75	10.9	6.3	9.8	22	26	5	6.8	6
Altra Instinct 4.0 Review	Altra	Instinct 4.0	Worth considering	$120	6.0	9.8	15.3	29	25	-1	5.9	5
Asics Tarther Kainos 3 Review	Asics	Kainos	Worth considering	$130	10.0	6.9	10.7	17	27	9	6.8	6
Altra King MT 1.5 Review	Altra	King MT	Recommended	$140	7.5	10.7	16.7	19	21	3	8.0	5
Saucony Kinvara 8 Review	Saucony	Kinvara 8	Best of the Best	$110	9.3	8.6	13.4	26	31	3	8.0	5
Altra Lone Peak 3.5 Review	Altra	Lone Peak	Highly Recommended	$120	4.2	11.4	17.7	24	25	4	4.8	5
Nike Zoom Streak LT 3 Review	Nike	LT3	Best of the Best	$80	9.8	5.4	8.4	16	21	5	5.3	7
Nike Zoom Streak LT 4 Review	Nike	LT4	Recommended	$90	8.5	5.5	8.5	15	21	3	4.6	6
Nike LunarSpider R5 Review	Nike	LunarSpider	Recommended	$125	6.9	6.7	10.4	17	21	3	4.6	6
Hoka Mafate Speed Review	Hoka	Mafate	Best of the Best	$170	7.6	11.9	18.5	39	40	4	9.0	1
Pearl Izumi EM Road N0 v2 Review	Pearl	N0	Highly Recommended	$100	7.9	6.5	10.1	14	20	4	5.2	8
Saucony Nomad Review	Saucony	Nomad	Worth considering	$110	4.3	10.5	17.2	25	27	2	4.5	4
Hoka Odyssey Review	Hoka	Odyssey	Highly Recommended	$130	8.5	9.4	14.6	37	45	5	8.0	3
Altra Olympus 2.5 Review	Altra	Olympus	Highly Recommended	$150	4.6	11.8	18.4	35	34	0	5.4	6
Altra One 3.0 Review	Altra	One	Recommended	$100	6.1	8.8	13.7	23	23	0	5.4	6
Altra Paradigm 4.0 Review	Altra	Paradigm	Highly Recommended	$150	5.3	11.0	17.1	28	30	5	5.8	8
Asics Piranha SP 5 Review	Asics	Piranha	Recommended	$100	10.1	4.2	6.5	11	15	3	4.2	9
Brooks PureFlow 5 Review	Brooks	PureFlow	Worth considering	$110	6.0	9.7	15.1	26	29	5	5.8	8
Salming Race Review	Salming	Race	Worth considering	$130	6.9	6.5	10.1	16	19	4	4.5	6
Altra Escalante Racer Review	Altra	Racer	Highly Recommended	$140	6.6	7.6	11.8	24	26	6	5.0	8
New Balance RC1600 v2 Review	New Balance	RC1600	Highly Recommended	$110	8.8	5.6	8.7	15	21	5	4.9	8
New Balance RC5000v2 Review	New Balance	RC5000v2	Best of the Best	$125	14.2	4.0	6.2	13	21	6	5.7	7
Skechers GoRun Ride 3 Review	Skechers	Ride	Worth considering	$85	5.9	8.5	13.2	18	28	6	5.0	8
Nike RN Distance 2 Review	Nike	RNDist2	Worth considering	$120	8.0	9.2	14.3	25	28	4	7.4	7
Inov-8 RoadXTreme 220 Review	Inov-8	RXT-220	Worth considering	$120	5.2	8.0	18.2	14	17	3	4.2	8
Salomon Sense Ride Review	Salomon	Sense	Worth considering	$120	8.5	10.0	15.6	26	29	6	8.5	0
Altra Solstice Review	Altra	Solstice	Highly Recommended	$90	7.1	8.1	12.5	23	25	0	5.7	5
Topo ST-2 Review	Topo	ST-2	Highly Recommended	$90	8.2	7.3	11.4	20	18	0	6.0	7
Hoka Stinson Lite Review	Hoka	Stinson	Highly Recommended	$160	7.3	11.6	18.1	35	40	6	8.5	0
Altra Superior	Altra	Superior	Highly Recommended	$110	5.6	9.9	15.5	21	25	-1	5.5	4
Adidas Takumi Sen 3 Review	Adidas	Takumi Sen 3	Highly Recommended	$160	7.7	6.6	10.2	17	21	4	5.1	5
Topo Terraventure	Topo	Terraventure	Review Pending	$110	2.6	10.8	27.5	24	24	0	2.8	10
Altra Timp Review	Altra	Timp	Best of the Best	$130	3.7	11.6	18.1	30	31	-1	4.3	6
Altra Torin 2.0 Review	Altra	Torin	Worth considering	$125	3.4	9.6	20.7	30	25	1	3.3	9
Altra Torin 3.5 Review	Altra	Torin 3.5	Worth considering	$125	5.8	9.3	14.5	27	28	0	5.4	8
Hoka Tracer Review	Hoka	Tracer	Recommended	$130	7.2	7.4	11.5	21	24	2	5.3	5
Merrell Trail Glove 4 Review	Merrell	Trail Glove 4	Best of the Best	$100	3.4	8.4	23.8	13	13	0	2.8	10
Topo Tribute Review	Topo	Tribute	Recommended	$100	5.9	7.3	11.4	20	18	-1	4.3	6
Mizuno Wave Universe 5 Review	Mizuno	Universe	Highly Recommended	$125	10.7	3.1	10.6	9	12	1	3.3	9
Altra Vanish-R Review	Altra	Vanish-R	Recommended	$100	16.1	5.3	8.2	19	21	4	8.5	6
Merrell Vapor Glove 3 Review	Merrell	Vapor Glove 3	Highly Recommended	$85	2.1	6.1	27.6	6	5	0	1.3	10
Nike Vaporfly 4% Review	Nike	Vaporfly	Best of the Best	$250	10.4	7.2	11.2	25	37	8	7.5	2
New Balance Vazee Pace Review	New Balance	Vazee Pace	Worth considering	$110	6.0	8.6	13.4	18	24	6	5.2	5
Asics TartherZeal 3 Review	Asics	Zeal	Worth considering	$140	10.9	6.3	9.8	17	27	9	6.8	6
Saucony Zealot 3 Review	Saucony	Zealot3	Recommended	$130	8.9	9.5	14.8	29	32	4	8.5	6
Nike Zoom Fly Review	Nike	Zoom Fly	Worth considering	$150	8.3	8.7	13.5	29	36	8	7.2	3

It's not a running shoe, but I love the Hoka Tor Ultra hiking boot and I've tested the Altra Lone Peak Boot, the Hoka Tor Speed 2, and the Inov-8 Roclite 325 hiking boots
Older shoe reviews: Saucony Hattori Review, Mizuno Cursoris Review, Skechers GO Bionic 2 Review, Hoka Clifton Review, Saucony Virrata 2 Review, Brooks PureCadence 3 Review, Brooks PureConnect 3 Review, Brooks PureFlow 3 Review, Skechers GO Bionic 2 Review, New Balance 980 Review, Brooks Transcend 2 Review, Hoka Huaka Review, Patagonia EVERlong Review, Asics 33-DFA Review, Hoka Conquest Review, Saucony Cortana Review, Puma Faas 100 R Review, Saucony Fastwitch Review, Nike Free Review, Asics Gel Lyte 33 Review, Skechers GOmeb Speed Review, Skechers GOrun Ultra Road Review, Nike LunaRacer Review, Altra Paradigm Review.

Asics 33-DFA Review

Contents

1 Characteristics

2 Comparisons

2.1 Altra 33-DFA‏ and Asics Gel Hyper Speed

2.2 Altra 33-DFA‏ and Hoka Clifton

2.3 Altra 33-DFA‏ and Saucony Kinvara

2.4 Asics 33-DFA and Asics GT 2000

3 Cushioning and Shoes

4 Visualizing the Attributes of the Asics 33-DFA

5 A Comparison with other Recommended Shoes

Fellrnr.com, Running tips