Adidas Ultra Boost 21 Boston Marathon (2021)
(6,073 reviews)
Prototype after prototype. Innovation after innovation. Testing after testing. Meet us in the hot pursuit of the pinnacle harmonization of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.
Prototype after prototype. Innovation after innovation. Testing after testing. Meet us in the hot pursuit of the pinnacle harmonization of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.
$223.00
in 1 offers
Colour:
Adidas Ultra Boost 21 Boston Marathon (2021)
$223.00
(6,073 reviews)
Prototype after prototype. Innovation after innovation. Testing after testing. Meet us in the hot pursuit of the pinnacle harmonization of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.
Prototype after prototype. Innovation after innovation. Testing after testing. Meet us in the hot pursuit of the pinnacle harmonization of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.
Colour:
Size
6
Price comparison
Last updated at 30/07/2025 17:56:05
Price history
Price history
Reviews
15 February 2024
AJ
originally posted on topsandbottomsusa.com
Fits small I need a 9 1/2. Do you send me a return label. I have emailed 2x with 1 response saying send back the 9 and buy the 9.5. What is the process (next steps) was my
next email with no response.
next email with no response.
4 January 2024
John H.
originally posted on stockx.com
Sneakers are well constructed and very comfortable but wish I had a half size down but this is no big surprise with Adidas crazy sizing methods .but guess thankful to be able
to cop these period since there's not to many of these in this exact colorway still available
to cop these period since there's not to many of these in this exact colorway still available
Amazing shoe!
28 March 2021
Alex
originally posted on roadrunnersports.com
I've been a lifelong Nike endorser until these came out! Amazing shoe! They take a bit to break in but once they do you'll never go back! I was a huge fan of the Nike free
runs and was skeptical that these could even come close... but they did! This has been by far my favorite shoe! I used it for track and xc training.
runs and was skeptical that these could even come close... but they did! This has been by far my favorite shoe! I used it for track and xc training.
Price comparison
Updated 1 day agoStockX
$223.00
+$34.95 delivery
Price history
Price history
Reviews
15 February 2024
Fits small I need a 9 1/2. Do you send me a return label. I have emailed 2x with 1 response saying send back the 9 and buy the 9.5. What is the process (next steps) was my next email with no response.
AJ
originally posted on topsandbottomsusa.com4 January 2024
Sneakers are well constructed and very comfortable but wish I had a half size down but this is no big surprise with Adidas crazy sizing methods .but guess thankful to be able to cop these period since there's not to many of these in this exact colorway still available
John H.
originally posted on stockx.comAmazing shoe!
28 March 2021
I've been a lifelong Nike endorser until these came out! Amazing shoe! They take a bit to break in but once they do you'll never go back! I was a huge fan of the Nike free runs and was skeptical that these could even come close... but they did! This has been by far my favorite shoe! I used it for track and xc training.
Alex
originally posted on roadrunnersports.comDecent shoes for heel strikers
30 December 2023
These shoes are pretty decent. They have plenty of cushioning in the heel for heel strikers. I’m enjoying them for my runs.
JMS1223
originally posted on Academy Sports + OutdoorsGreat response, and cushion as advertised
8 March 2021
I really liked the Ultraboost 20s and bought 2 pairs of the Ultraboost 21 to add in my rotation. I work out 4-5 days a week, doing cardio and weights. And these feel really good on my feet. I am not an avid runner, but as advertised, the additional boost feels more responsive and more cushioned. If you liked the Ultraboost 20s, you'll like the upgrade on the Ultraboost 21s. I am a heavy set guy, I've lost over 60 lbs in the last year, and have put my Ultraboosts through the test...
Bigbeebs
originally posted on finishline.comHonest review.
25 February 2022
The fit is almost tight enough not to need any laces. I havent tried the size up. I'm normally a 8.5 on Nike but this is snug fit. The archilles tendon has two plastics to hold the shoe in and its tight if you use any cross training or side movements. Just good for running. Been running on a treadmill and not used outdoor.The top lip of my left shoe flips back and doesnt look all that great when i wear it. If only they moved the adidas label just a bit higher so it wont flip back .
originally posted on Academy Sports + Outdoors
I Don't Reccomend the Adidas Ultra Boost 21
10 August 2021
I run from 1 to 1.5 hours daily and have for about 50 years. I buy two pairs of shoes at a time, rotate them daily, and replace them with another pair in about three months. I have worn Adidas exclusively for about 30 years. The Ultra Boost 21 is the most uncomfortable Adidas shoe I have worn. I blame the thick plastic "plates" housing the eyelets through which the shoelaces run. With little effort, the edges of the plates could be filed to a knife's blade sharpness. They are that thick. They are so thick that they inflexible, probably by design. And, other than hold the eyelets for the shoelaces, their only function seems to be to cause the upper parts of my feet to hurt. These shoes are miserable to wear. I am stubborn, so I am going to wear them for three months. ... MoreI run from 1 to 1.5 hours daily and have for about 50 years. I buy two pairs of shoes at a time, rotate them daily, and replace them with another pair in about three months. I have worn Adidas exclusively for about 30 years. The Ultra Boost 21 is the most uncomfortable Adidas shoe I have worn. I blame the thick plastic "plates" housing the eyelets through which the shoelaces run. With little effort, the edges of the plates could be filed to a knife's blade sharpness. They are that thick. They are so thick that they inflexible, probably by design. And, other than hold the eyelets for the shoelaces, their only function seems to be to cause the upper parts of my feet to hurt. These shoes are miserable to wear. I am stubborn, so I am going to wear them for three months. I will then use the plastic plates to scrape paint off walls. I gave the shoe two stars because everything but the plastic plates is okay. I do not recommend this shoe.
Christopher
originally posted on roadrunnersports.comQuality and style you would expect from Ultraboosts!
8 July 2021
All out red looks exteemely sharp! The extended boost sole looks sharp and provides additional stability. Upper is well made with very little evidence of stich/glue lines. Can wear casually or for running but sole is not flat or firm enough for most gym leg-day exercises. We ordered a full size down as the shoe runs noticably large.
Alex
originally posted on finishline.comReally Help with foot pain
1 March 2021
Long distances and wearing these all day every day Man they are great for that......We're going to run in a little heavy but listen I'm not going racing.If you walk man you could take these guys on a 6 mile walk and have your feet and knees be right as rain. The white ones will be impossible to keep clean.
Truby
originally posted on roadrunnersports.comStill the one!
19 March 2021
I've had the last three versions of this shoe including an ST version back in the day and this shoe continues to impress. I do a lot of hill work and the new toe plate has been great working through my transitions. I'm normally a size 13 but I always size up for the extra toe box room and this one continued with that trend. The toe plate makes the shoe a tad firmer on the ball of the foot but the performance is still there and it's my new daily work horse. I'm 6'1" and 220lb and this shoe definitely gets the job done.