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Sunday, March 20, 2022

Asics Gel Kinsei Blast Review


Asics Gel Kinsei Blast Review:
The Whole Asics Kitchen Sink in One
By Chief Contributor Matt Klein


The Asics Gel Kinsei series has been a mythical creature of sorts. Years ago (now well over a decade) when I worked in running retail stores, the Kinsei was the most expensive shoe on the market and was only seen if someone special ordered it. Featuring more Asics Gel than any other shoe, it was purported to be the most cushioned and advanced shoe in the line. Being someone who preferred lighter and more minimal shoes at the time, I steered clear. Now that I will run in anything given the chance, the Asics Gel Kinsei Blast sparked my interest given the complete overhaul in design. Featuring a maximal stack and rockered design, a Pebax plate, more Gel and FF Blast, the Kinsei Blast returns with a new look but maintains most of its roots.

Price: $179.95 at Running Warehouse
Weight: 11.7 oz, 332 g (men's size 9), 9.9 oz, 280 g  (women's size 8)
Stack Height: 39 mm / 29 mm
Drop: 10 mm
Classification: Maximal Daily Training Shoe



RUNNING SHOE SUMMARY

The Asics Gel Kinsei Blast is a highly cushioned, maximal shoe that combines a high stack height, rockered ride with a plated midsole. Featuring a huge amount of gel and FF Blast, a Pebax plate is sandwiched in the middle to provide some rigidity to this rockered ride. A narrow last and a plush narrow fit makes this shoe best for those with narrow and stable/rigid feet. The Asics Gel Kinsei Blast combines the high cushioned and plush design of previous Kinsei shoes with current day influences from maximalist and plated shoes for a heavy-duty daily training shoe for high mileage.



FIT 

The Asics Gel Kinsei Blast fits me slightly short in my normal men's size 10. While the upper does stretch a little, those between sizes should consider going up a size unless you like a snugger/tighter fit in the forefoot. The fit overall is snug/narrow throughout thanks to a tapered forefoot, aggressive toe spring, a narrow fit and an extremely cushioned heel collar. While there is a thick internal and external heel counter, I did not notice it due to the thick pad of heel collar cushioning. As this breaks down those with heel counter sensitivities may need to be careful, but after 30 miles I had no issues. The internal and external heel counter travel fairly far forward on both sides of the heel, which locks the rearfoot down well. I did not have to lace lock this shoe at all and did not have any slippage issues. The tongue has a unique design, with cushioning on the sides and being thinner in the middle. It is gusseted farther down in the shoe and I did have some lateral translation of the tongue until I tied the laces a little tighter and locked down the upper lace attachment. The upper is an engineered knit mesh that breathes decently. There are small air holes upfront which add some breathability, but the knit mesh runs on the warmer side.

The forefoot tapers quickly and is quite narrow. The toe spring hold the toes in extension, which further shortens and narrows the shoe. The inner lining of the upper is comfortable against the foot except for the toebox, which contains slightly rougher material as part of a flexible toe guard. This causes a significant amount of chaffing for me, thus I would suggest wearing socks with these. For that reason and the others outlined above, the fit of the Asics Gel Kinsei Blast will work best for those with narrow feet or those who want a snug fit. 



PERFORMANCE 

The Asics Gel Kinsei Blast is a highly cushioned, durable but heavy daily training shoe. Unlike many maximal stack height shoes, there is a 10mm drop. This provides a 39mm heel stack height, which provides an incredibly cushioned landing thanks to full-length FF Blast and rearfoot gel. The midfoot and forefoot are also highly cushioned and those that are forefoot strikers have a specifically placed block of gel at the lateral forefoot for landings. The ride is stiff with an aggressive rocker. The rearfoot has a significant bevel with two split gel pods. This provides a solid heel transition and I am hopeful ASICS will continue to provide solid bevels in their shoes. The forefoot has an extremely aggressive toe spring that holds the toes in extension. It feels like you are falling forward as you hit the front. I have however had several episodes where it felt like I mildly strained some of my intrinsic toe flexors in this shoe, so those sensitive to toe spring or that do not have adequate toe extension should avoid this. This rocker is important as a full-length Pebax plate runs through the midsole. It is extremely stiff and the sole has little to no flexibility. This makes the rocker extremely apparent no matter where you land in this shoe.

As mentioned there is a 10mm drop, but it was not as noticeable given how rockered the sole is and how much it compresses for me. With the high stack height, large amounts of cushion, gel and plate, the shoe is heavy. It is a solid choice for easy runs or recovery runs, but is absolutely too heavy for anything uptempo. This is further emphasized by how incredibly durable the outsole is. I have over 30 miles in this shoe and have not managed to make even a dent in the outsole. So those that want a highly cushioned and aggressively rockered shoe for daily miles may want to consider the Asics Gel Kinsei Blast. 




STABILITY 

The Asics Gel Kinsei Blast is a neutral shoe but is unstable for me. There are several components that could add stability, but they are nullified by the narrow last/shape underfoot. There is a full-length Pebax plate that has a small elevation on the medial midfoot. There is both an internal and external heel counter that runs fairly far forward. There are midsole sidewalls on both the medial and lateral side of the midfoot. Finally the sole is aggressively rocker and rolls you forward. However, for such a maximal and high stack height shoe, the last/shape of the shoe is incredibly narrow. The heel is already on the narrow side, but the midfoot is extremely slim and wobbly. I had an extremely difficult time running farther than 4-5 miles in this shoe at a time due to the instability of the midfoot. This is due to the narrowness combined with how soft the midsole is and the incredibly tall stack height. Thus, despite some of the measures, this shoe is best for those with stable mechanics, particularly at the midfoot.

THOUGHTS AS A DPT / FOOTWEAR SCIENCE

In shoes that have maximal stack heights and stiff rides, toe spring is necessary to allow a transition over the forefoot. However, the way in which the toe spring is implemented can vary. From a clinical perspective, toe spring can be helpful for those that do not have the normal >60 degrees of metatarsophalangeal (MTP) joint extension. The toes do not extend, so the toe spring replaces that. However, this assumes the toe spring is integrated into the forefoot without impacting the position of the toes, ie allowing them to remain in a neutral position. This can be helpful for a variety of toe conditions including those with arthritic changes in those joints, turf toe, gout (which commonly affects the 1st MTP joint), forefoot nerve or pressure injuries or stiff toe flexors (flexor digitorum longus/brevis, flexor hallucis longus/brevis, flexor digiti minimi).

toespring

Image via Pace Athletic

For these conditions, shoes should have toe spring that comes up to the foot but keeps in the toes in a neutral position. Something that actively holds the toes in extension will likely exacerbate the issues mentioned above. Another potential issue is also due to the fact that this can functionally shorten the shoe, causing people to curl their toes in order to compensate for the length issue, which may put them in a hammer toe-like position. Additionally, even if you have normal muscle length, holding a muscle at its lengthened end range is not an optimal place to continually expose to high loads. Muscles are length specific in their function. Typically they can produce the most force in their midrange and produce less force in highly lengthened or shortened positions due to a concept called the length-tension relationship. Since muscles produce less force/torque while in an extremely lengthened position, this puts them at risk for potential strains or spasms. I experienced this several times with the Asics Gel Kinsei Blast and knew what it was from immediately. The only population that might benefit from this is those with either toe flexor weakness or calf weakness. The aggressiveness of the toe spring here does allow for an aggressive roll forward, which may be beneficial for those with limited ability to push off. However, that is a small population and for others that really want to run in this shoe, I would suggest a half size up to compensate. 



RECOMMENDATIONS

I have two major recommendations for this shoe. My first would be to adjust the toe spring so that the toes are not held in extension. It is best to keep the toes in a neutral position, so lower the toes and extending the toe spring may be beneficial, particularly for a shoe with this much stack height and stiffness. This also makes the shoe feel a half size short, so that could be modified. The second is to widen the last of this shoe. A tall stack height shoe cannot have such a narrow last throughout the length of the shoe. Combine that with a soft sole and this will cause problems for anyone with any stability issues at all. Or it will put others at risk for an easy ankle sprain. The narrowness makes the several stability attempts useless, so wide the sole and let them shine. There are many other ways to reduce weight, but this isn't a great one when combined with the design of this shoe. The Asicxs Gel Kinsei Blast has a ton of potential, but the aggressive toe spring and extremely narrow last limits it use to a small population for running.

WHO THIS SHOE IS FOR 

The Asics Gel Kinsei Blast is a neutral daily training maximal shoe that is highly cushioned and aggressively rockered. Those with narrow and rigid feet will enjoy this shoe given the narrow fit and inherantly unstable midfoot. There are a few methods of stability, that although nullified by the narrow last and soft sole, do a great job of locking the feet on the sole. The aggressive rocker is best for those who want to be rolled forward, but the toe spring will require that the user have adequate toe extension and toe flexor range of motion. A solid looking shoe that may double well for those who want a highly cushioned casual shoe and short to moderate distance running shoe. The Asics Gel Kinsei continues its legacy as a high end and extremely cushioned piece of footwear that attempts to pack all the latest technologies in, although there may need to be some modifications to make it biomechanically appropriate for a larger population of runners.


GRADING 

Matt
Fit: B- (Narrow fit with comfortable engineered knit. Fits half size short due to forefoot taper and aggressive toe spring)
Performance: 
B- (Soft ride, heavyweight and aggressive rocker makes this shoe best for easy mileage and recovery runs. The plate adds stiffness to the sole, but the weight stops it from doing anything fast. Still has a solidly bounce sole)
Stability: C- [Neutral] (Several methods of natural stability, but these are all nullified by a midfoot and last that is way too narrow on a soft and high stack height sole)
DPT/Footwear Science: B-/C+ (Several attempted methods of stability, however not biomechanically appropriate design in toes with aggressive toe spring. Will limit this shoe to a small population. This shoe has potential though)
Personal: C- (I want to like this shoe more, but the narrow last, aggressive toe spring and tapered toe box make this shoe extremely uncomfortable for me.
Overall: C+ (A narrow fitting, highly cushioned, aggressively rockered maximal daily training shoe for those with neutral mechanics)
   

SHOP | SUPPORT DOR

Price: $179.95 at Running Warehouse

*Using the link to purchase helps support Doctors of Running. Thanks so much!

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FURTHER READING

Nike Structure 24
-
Slightly refined update for the mild stability trainer
Saucony Axon 2 - A highly valued rockered ride at $100
Saucony Freedom 5 - A super foam in a lower profile built for crosstraining
Diadora Mythos Blushield 6 - The Italian maker's stability shoe model, with a plush underfoot
Xtep RC260
- A decently priced, plated pebax trainer from the Chinese brand

Find all Shoe Reviews at Doctors of Running here.

Thanks for reading!

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TESTER PROFILES:

Matthew Klein, PT DPT PhD(c) OCS FAAOMPT

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

Dr. Matthew Klein is a 150 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.  The stability guy of the group, he also prefers a little stability in his footwear. However, as a researcher, clinician and running shoe aficionado, he will run in anything. 

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.

***Disclaimer: These shoes were provided free of charge in exchange for a review.  We thank the people at ASICS 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.

Please feel free to reach out, comment and ask questions!
Contact us at doctorsofrunning@gmail.com

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Saucony Freedom 5
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