Show up for yourself. These adidas Ultraboost 21 Running Shoes make it easier. Lightweight but without sacrificing an ounce of support, the adidas Primeknit+ upper adapts to the changing shape of your foot as you push forward. Responsive Boost cushioning gives you an energized feeling that reminds you that you can always go one more step, maybe one more block or perhaps another mile.
Show up for yourself. These adidas Ultraboost 21 Running Shoes make it easier. Lightweight but without sacrificing an ounce of support, the adidas Primeknit+ upper adapts to the changing shape of your foot as you push forward. Responsive Boost cushioning gives you an energized feeling that reminds you that you can always go one more step, maybe one more block or perhaps another mile.
in 2 offers
The lowest price for Adidas Ultra Boost 21 Carbon Solar Red right now is $126.05 at Solestop.com, compared across 2 retailers.
The all-time low was $126.05 on 12 May 2026. That's the lowest price we've ever tracked — a great time to buy.
Prices last updated 12 May 2026.
Adidas Ultra Boost 21 Carbon Solar Red
Show up for yourself. These adidas Ultraboost 21 Running Shoes make it easier. Lightweight but without sacrificing an ounce of support, the adidas Primeknit+ upper adapts to the changing shape of your foot as you push forward. Responsive Boost cushioning gives you an energized feeling that reminds you that you can always go one more step, maybe one more block or perhaps another mile.
Show up for yourself. These adidas Ultraboost 21 Running Shoes make it easier. Lightweight but without sacrificing an ounce of support, the adidas Primeknit+ upper adapts to the changing shape of your foot as you push forward. Responsive Boost cushioning gives you an energized feeling that reminds you that you can always go one more step, maybe one more block or perhaps another mile.
Last updated at 12/05/2026 22:06:22
Adidas Running Men Ultraboost 21 Black Red FZ2559 11
Delivery $80.67
Adidas UltraBoost 21 'Carbon Solar Red' | Black | Men's Size 11
Delivery between 14–21 May $25
originally posted on roadrunnersports.com
A good new version of the Boost! Can definitely feel the extra Boost while being a bit stiffer! Not a carbon plate stiffness BUT solid. Use this shoe for everyday miles. Then buy a carbon plate shoe for speed or tempo runs. Much better wear on tread then the old continental rubber. Solid shoe for 50+ miles per week
originally posted on roadrunnersports.com
It has been over a decade since a last ran on Adidas cause I always found their fit too narrow. I tried the UB 21 and surprisingly it fit me well. The Prime Blue material is top notch and good quality and stretchy. One of the draws to me for trying this shoe was aesthetics and in my opinion the best looking running shoe out right now. However, when running on it it was a different story. I had considerable heel slip more on my right than left heel. I felt the weight of the shoe when picking up the pace to my normal zone 2 pace and when picking it up to marathon and tempo pace the boost cushioning feels flat and dead. The bounce goes away and I didn't feel any responsiveness or pop from the plate on the bottom. It actually felt the opposite like I was fighting the ... MoreIt has been over a decade since a last ran on Adidas cause I always found their fit too narrow. I tried the UB 21 and surprisingly it fit me well. The Prime Blue material is top notch and good quality and stretchy. One of the draws to me for trying this shoe was aesthetics and in my opinion the best looking running shoe out right now. However, when running on it it was a different story. I had considerable heel slip more on my right than left heel. I felt the weight of the shoe when picking up the pace to my normal zone 2 pace and when picking it up to marathon and tempo pace the boost cushioning feels flat and dead. The bounce goes away and I didn't feel any responsiveness or pop from the plate on the bottom. It actually felt the opposite like I was fighting the shoe just to get a quicker turnover. It also felt clunky. When at jogging pace the shoes felt fine and could feel the boost cushioning. Overall not the cushioned daily trainer I expected and this version has leaned more towards the casual athleisure category. This is a great walker/jogger but as a shoe part of a rotation for training it's a hard pass. Really wanted to like this shoe but for what I bought it for it's a big disappointment and will be returning it.
originally posted on roadrunnersports.com
This shoe is really comfortable, lots of cush which is important for me with a bad knee. Nice fit on the heel, really locks it in so it doesn't roll around, without feeling constrained. Good arch support. Wore them today for the first time right out of the box and they were soooo comfortable. No breakin needed.
| Style | FZ2559 |
| Release Date | 06/01/2021 |
Adidas Running Men Ultraboost 21 Black Red FZ2559 11
Delivery $80.67
Adidas UltraBoost 21 'Carbon Solar Red' | Black | Men's Size 11
Delivery between 14–21 May $25
A good new version of the Boost! Can definitely feel the extra Boost while being a bit stiffer! Not a carbon plate stiffness BUT solid. Use this shoe for everyday miles. Then buy a carbon plate shoe for speed or tempo runs. Much better wear on tread then the old continental rubber. Solid shoe for 50+ miles per week
It has been over a decade since a last ran on Adidas cause I always found their fit too narrow. I tried the UB 21 and surprisingly it fit me well. The Prime Blue material is top notch and good quality and stretchy. One of the draws to me for trying this shoe was aesthetics and in my opinion the best looking running shoe out right now. However, when running on it it was a different story. I had considerable heel slip more on my right than left heel. I felt the weight of the shoe when picking up the pace to my normal zone 2 pace and when picking it up to marathon and tempo pace the boost cushioning feels flat and dead. The bounce goes away and I didn't feel any responsiveness or pop from the plate on the bottom. It actually felt the opposite like I was fighting the ... MoreIt has been over a decade since a last ran on Adidas cause I always found their fit too narrow. I tried the UB 21 and surprisingly it fit me well. The Prime Blue material is top notch and good quality and stretchy. One of the draws to me for trying this shoe was aesthetics and in my opinion the best looking running shoe out right now. However, when running on it it was a different story. I had considerable heel slip more on my right than left heel. I felt the weight of the shoe when picking up the pace to my normal zone 2 pace and when picking it up to marathon and tempo pace the boost cushioning feels flat and dead. The bounce goes away and I didn't feel any responsiveness or pop from the plate on the bottom. It actually felt the opposite like I was fighting the shoe just to get a quicker turnover. It also felt clunky. When at jogging pace the shoes felt fine and could feel the boost cushioning. Overall not the cushioned daily trainer I expected and this version has leaned more towards the casual athleisure category. This is a great walker/jogger but as a shoe part of a rotation for training it's a hard pass. Really wanted to like this shoe but for what I bought it for it's a big disappointment and will be returning it.
This shoe is really comfortable, lots of cush which is important for me with a bad knee. Nice fit on the heel, really locks it in so it doesn't roll around, without feeling constrained. Good arch support. Wore them today for the first time right out of the box and they were soooo comfortable. No breakin needed.
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 .
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.
I purchased the 21 Boost based on previous experience with the 20's. While these are very different in looks, they provide the same comfort. I'm not a runner, but the cushion in these really help alleviate back pain during long time use. The color way is amazing, I'm a fan of the small details in the upper of the shoe with small touches of the accent color throughout. If you're looking to buy a pair but find yourself on the fence, make the jump. Your feet and back will thank you and you'll get plenty of compliments as an added bonus.
Not sure if others will experience this: I want to like these shoes. I kept telling myself I did like them, and that I just needed to break them in. I've going on multiple walks, and two runs, and the shoes are too uncomfortable to wear. I think they are too tight around the middle of the foot, but I can't explain why they hurt so much. They just make the middle of my feet ache intensely during walks/runs.
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.
I'm a fan of ultra boost tech, have had every model and decided to buy this one on sale. When it first arrived I was super excited to try them on. Out the box, my first impression was that it seemed to follow previous models and was made from solid materials, once on foot my feelings changed. Super comfortable, light weight but LONG. Mens size 8 looked more like a 10. The silhouette was more like a clown shoe paired with a huge heel and I just couldn't keep them.
I'm a recreational runner, some trail and some road. I very much enjoyed the UB 19's and decided to skip a version and go fro the 21. The magic is still there in the springy, comfy road feel and still good to go on hardback trail. The change in the upper Wass the downfall and the reason for 3 stars instead 5, the toe box is not as roomy and really punished my big toes. If you can wear the Nike Peg 37 without issue, this will likely be ok for you. I am also a big fan of the Peg, but similarly the latest version is to tight on the big toe for me. Have great run, there is never a bad one.
| Style | FZ2559 |
| Release Date | 06/01/2021 |
