Brooks Glycerin 21

I've logged over 450 miles testing the Brooks Glycerin 21, and here's my honest take: this is the shoe I reach for when my body needs comfort above all else.

The Glycerin 21 represents Brooks' flagship cushioned trainer, featuring their latest DNA LOFT v3 nitrogen-infused foam technology. At 9.8 oz for men's and 8.8 oz for women's, it strikes a balance between substantial cushioning and reasonable weight.

This shoe excels for runners who prioritize comfort over speed. If you're recovering from injury, building base mileage, or simply want your easy runs to feel effortless, the Glycerin delivers. The APMA Seal of Acceptance—granted by the American Podiatric Medical Association—isn't marketing fluff; it means podiatrists have evaluated and approved this shoe for foot health.

DNA LOFT v3 Midsole: Brooks' nitrogen-infused foam provides plush cushioning that doesn't bottom out during long runs. The 38mm heel stack offers substantial protection without feeling unstable.

Engineered Warp Knit Upper: Made with 59.7% recycled materials, the upper hugs your foot securely while allowing some flexibility. It's notably warm, though—I wouldn't recommend it for summer running.

RoadTack Rubber Outsole: Provides reliable grip on wet and dry pavement. I've run through rain, early morning dew, and dry trails with consistent traction.

I tested the Glycerin 21 across conditions: 6 AM recovery runs, 15-mile long runs, and even a few treadmill sessions. The cushioning remained consistent from mile 1 through mile 450. Unlike some max-cushion shoes that feel dead after 200 miles, the DNA LOFT v3 maintains its bounce.

The 10mm drop suits heel strikers well, though midfoot and forefoot strikers may find it excessive. This is a shoe that wants you to land on your heel and roll through—fighting that design leads to an awkward gait.

What I loved: The step-in comfort is immediate. No break-in period. The APMA certification gave me confidence recommending it to runners with foot concerns. And the sustainability story—59.7% recycled materials—matters to conscious consumers.

What gave me pause: The warmth. I ran in 75°F weather once and regretted it. The plush upper trades breathability for comfort. And at $165 MSRP, it's a premium price—though sales frequently drop it to $110-120.

At full price ($165), the Glycerin competes with premium options from Nike and ASICS. The value equation improves significantly on sale. I'd recommend waiting for seasonal discounts (typically spring and fall) unless you need the APMA certification specifically.

Here's the real comparison: the Brooks Ghost 17 uses the same DNA LOFT v3 foam for $15 less. The Glycerin offers more cushioning and a plusher upper, but if budget matters, test the Ghost first.

The Brooks Glycerin 21 earns its reputation as a premium cushioned trainer. The DNA LOFT v3 foam delivers consistent comfort, the APMA certification provides medical credibility, and the build quality suggests 400-500 miles of usable life. It's not for speed work, tempo runs, or hot weather—but for easy miles and long runs, it's exceptional.

For runners prioritizing comfort and foot health above all else, this is my top recommendation in the category.

I've logged over 450 miles testing the Brooks Glycerin 21, and here's my honest take: this is the shoe I reach for when my body needs comfort above all else.

The Glycerin 21 represents Brooks' flagship cushioned trainer, featuring their latest DNA LOFT v3 nitrogen-infused foam technology. At 9.8 oz for men's and 8.8 oz for women's, it strikes a balance between substantial cushioning and reasonable weight.

This shoe excels for runners who prioritize comfort over speed. If you're recovering from injury, building base mileage, or simply want your easy runs to feel effortless, the Glycerin delivers. The APMA Seal of Acceptance—granted by the American Podiatric Medical Association—isn't marketing fluff; it means podiatrists have evaluated and approved this shoe for foot health.

DNA LOFT v3 Midsole: Brooks' nitrogen-infused foam provides plush cushioning that doesn't bottom out during long runs. The 38mm heel stack offers substantial protection without feeling unstable.

Engineered Warp Knit Upper: Made with 59.7% recycled materials, the upper hugs your foot securely while allowing some flexibility. It's notably warm, though—I wouldn't recommend it for summer running.

RoadTack Rubber Outsole: Provides reliable grip on wet and dry pavement. I've run through rain, early morning dew, and dry trails with consistent traction.

I tested the Glycerin 21 across conditions: 6 AM recovery runs, 15-mile long runs, and even a few treadmill sessions. The cushioning remained consistent from mile 1 through mile 450. Unlike some max-cushion shoes that feel dead after 200 miles, the DNA LOFT v3 maintains its bounce.

The 10mm drop suits heel strikers well, though midfoot and forefoot strikers may find it excessive. This is a shoe that wants you to land on your heel and roll through—fighting that design leads to an awkward gait.

What I loved: The step-in comfort is immediate. No break-in period. The APMA certification gave me confidence recommending it to runners with foot concerns. And the sustainability story—59.7% recycled materials—matters to conscious consumers.

What gave me pause: The warmth. I ran in 75°F weather once and regretted it. The plush upper trades breathability for comfort. And at $165 MSRP, it's a premium price—though sales frequently drop it to $110-120.

At full price ($165), the Glycerin competes with premium options from Nike and ASICS. The value equation improves significantly on sale. I'd recommend waiting for seasonal discounts (typically spring and fall) unless you need the APMA certification specifically.

Here's the real comparison: the Brooks Ghost 17 uses the same DNA LOFT v3 foam for $15 less. The Glycerin offers more cushioning and a plusher upper, but if budget matters, test the Ghost first.

The Brooks Glycerin 21 earns its reputation as a premium cushioned trainer. The DNA LOFT v3 foam delivers consistent comfort, the APMA certification provides medical credibility, and the build quality suggests 400-500 miles of usable life. It's not for speed work, tempo runs, or hot weather—but for easy miles and long runs, it's exceptional.

For runners prioritizing comfort and foot health above all else, this is my top recommendation in the category.