Brooks Reviews

Brooks Adrenaline GTS 21: Most Comfortable Running Shoes

gts 21 front


Buy Adrenaline GTS 21 on Amazon 

SCORE: 8.0

Weight:10 oz (Men's size 9)

Heel Drop: 12mm

Shoe Type: Max-Cushioned Stability Running Shoe

Terraine: Road: light trail, grass and pavement

Pace: Moderate



  • Stable
  • Highly breathable
  • Roomy toe box
  • Rides excellently
  • Responsive feel
  • Durable
  • Reliable


  • High heel drop of 12mm can be uncomfortable
  • It takes long for the midsole to break in, thus delaying that soft ride. 

 Take Away: Brooks Adrenaline GTS 21 is a stable running shoe designed perfectly for long-distance running. 



Brooks Adrenaline GTS 21 was released in November 2020. It has a similar appearance to the Brooks Ghost 13.  However, Brooks made some exciting changes with the Adrenaline 21 model. Notable changes include replacing the upper part with a highly breathable and yet flexible double mesh and proper utilization of DNA LOFT foam in the midsole.

In Brooks Adrenaline GTS 20, The DNA LOFT foam, a soft cushioning material, is placed strategically at the heel and extends to the midfoot area. Unlike in Adrenaline 20, the DNA LOFT foam extends from the heel to the forefoot to enhance cushioning and responsiveness. As max-cushioned stability running shoe, Adrenaline GTS 21 guarantees stability to runners with overpronation issues. It is also a joy to run in this shoe.


 Brooks Adrenaline GTS 21 Instant Impression

Looking at Brooks Adrenaline GTS 21, I saw a mix of plush and simplicity. I could hardly tell its difference from Brooks Adrenaline GTS 20. The upper is made of a double engineered mesh and has a 3D print, which gives the shoe a nice look and structure.

When I first slid my foot into this shoe, I felt pretty comfortable across the heel, midfoot, and toes. It is because the upper stretches and wraps nicely around the foot, and the heel collar, ankle collar, and tongue are sufficiently cushioned.

The toe box felt roomy yet not much of a wiggle room. Still, I did not feel my toes cramped together. 

The inner lining also felt seamless, and the feeling under the foot was somewhat soft.

When I took Brooks Adrenaline out, the first few steps felt quite uncomfortable and firm for two reasons: The heel drop of 12mm is relatively high, and the midsole did not break easily. It reminded me of the Asics Dynablast, which also boasts a high heel drop of 12mm.

Though it took longer to break in, the ride became softer with every mile. It took approximately 30miles for the midsole to breaks in to allow a gentle ride. In a short while, I got used to the high heel drop and experienced the soft and responsive nature of the DNA LOFT foam under the foot.

I have done about 60 miles with the Adrenaline GTS 21, and the running experience has been enjoyable.  


Brooks Adrenaline GTS 21 Upper Design and Fitting


The upper is made of a double-layered engineered mesh upper. It is highly breathable to keep the foot cool and dry. It is also stretchy, thus wraps around the foot to provide a secure fit. Because it stretches, the Adrenaline GTS 21 can comfortably fit someone with a wide foot. The flexibility of the mesh does not compromise the shoe's structure. The Brook's logo and 3D prints in the lateral sides combine to give the upper part a solid structure and enhance snug fit around the midfoot area.

 I also like the roomy toe box because it allows the toes to spread out naturally. My toes neither wiggled in the toe box nor cramped together. It was just the right fit for me.

Adrenaline GTS 21 fits true to size but does not command a tight fit. The upper is built to give just a relaxed fit for racking up long distances. It is also durable to withstand critical terrains and over 800 miles of running.

The tongue is gusseted, so it does not slip sideways or downwards. It also enhances a snug fit, especially in the midfoot area. The tongue is well padded. The padding is not thick but just enough.

The heel collar is also well padded to a pin that it feels soft in the fit. I did not experience any feeling of irritation.

The heel counter is solid but not very restrictive. It perfectly holds down the foot when running. 


Overall, Brooks did great with the upper. It stuck with what works and introduced better ideas. I love the upper part. It is perfectly engineered to suit a long-distance runner. Moreover, the upper looks audacious and plush.


Brooks Adrenaline GTS 21 Sole Design and Performance



Exciting upgrades of the Brooks Adrenaline GTS 21 are in the midsole. Most notable is the dual-density cushioning comprising DNA loft and BioMoGo DNA. Unlike in the Adrenaline GTS 20, Brooks ensured that the DNA LOFT cushioning extends from the heel to the forefoot. Brooks also replicated this change in the Ghost 13, and the impact has been an increased cushioning under the foot. I noticed experiencing a firm yet untaxing ride in the first 20 miles, but its responsiveness increased after the midsole broke inThe ride became soft and bouncy, and the transition from heel to toe felt seamless.

Brooks did away with the medial posts and went for the GuideRail technology. A GuideRail system has been common in the Brooks Transcend, and recently it was introduced in the Adrenaline and other stability models. The GuideRail system is placed strategically at the medial post and the lateral side of the heel.  

 You will appreciate the effectiveness of the GuideRail system if you are an overpronator. It ensures that the foot stays in its neutral position when running, thus preventing overpronation.



The outsole is a blown rubber for complete ground contact, reduced landing impact, and enhanced traction. Its difference from the Adrenaline GTS 20 is that it has more blown rubber at the outsole to increase the stability and longevity of the shoe. At 60 miles, I haven't noticed any wear at the outsole. It shows the extent to which this shoe is built to survive longer miles.

I noticed that the Omega Flex Grooves in the outsole keep the forefoot flexible.


Brooks Adrenaline GTS 21 Overall Performance

Adrenaline GTS 21 is super comfortable. It has a soft but responsive midsole. Hence, it rides soft. With the GuideRail, I felt that the shoe gave me excellent stability throughout my running period.

I felt comfortable running on the road. Because of its responsiveness and cushioning, I comfortably racked up long miles. However, it was only possible at a slow tempo because the Adrenaline performs relatively poorly in fast runs. Besides, 10oz feels somehow heavy in the foot and legs. Also, the 12mm high heel drop felt quite uncomfortable during the first few miles. After clocking some miles, I got used to the shoe, and my gait cycle became seamless and unhampered.  

My take is that Adrenaline GTS 21 competes well with the Saucony Guide, Brooks transcend, Asics GT 2000 9. However, it does not ride as firm as the Brooks Transcend or as soft as the Brooks Ravenna. Instead, it is a bridge between these shoes.


 Why You Should Buy Brooks Adrenaline GTS 21




Adrenaline GTS 21 is not too much of a flashy shoe, but just a simple and practical stability running shoe. It is an excellent daily trainer, especially for overpronators. The Adrenaline 21 performs well on the road, but you can also use it for treadmill running since it superb stability features.

You can add it to your rotations, especially if you prefer both a neutral and stable running shoe. It is a go for shoe if you are looking for comfortable long-distance running. Furthermore, Adrenaline GTS 21 is a durable running shoe. Since it does not show any wear at 60 miles, I believe it has a lifespan of more than 800 miles. 


Buy On Amazon

Brooks Men's Adrenaline GTS 21  

Brooks Adrenaline GTS 21 Women's


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Written By: James Riley. He is an experienced marathoner with thousands of miles  under his feet.

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