Which shoe is better: ASICS Novablast 4 or Brooks Glycerin 21?

The ASICS Novablast 4 and Brooks Glycerin 21 are tied dead-even with identical SoleVersus Meta-Scores of 82 PTS. Your choice should depend on specific geometry: the Novablast 4 features a 8mm drop and 260g weight, while the Glycerin 21 features a 10mm drop and 278g weight.

What is the difference in drop and weight between ASICS Novablast 4 and Brooks Glycerin 21?

The ASICS Novablast 4 weighs 260g with a 8mm drop (41.5mm heel / 33.5mm forefoot). The Brooks Glycerin 21 weighs 278g with a 10mm drop (38mm heel / 28mm forefoot). The Novablast 4 is 18g lighter. The drop difference is 2mm.

ASICS Novablast 4 vs Brooks Glycerin 21

Head-to-Head Comparison·Lab Telemetry

ASICS · Max Cushion

Novablast 4

AXIS_Y // 0.0M9 // 280mm

Stack41.5mm

Weight260g

Drop8mm

Full Audit→

Brooks · Max Cushion

Glycerin 21

Nitrogen-infused

AXIS_Y // 0.0M9 // 280mm

Stack38mm

Weight278g

Drop10mm

Full Audit→

8-Axis Telemetry Radar

Novablast82vsGlycerin82

Dead even · 82 PTS

Tap any axis node to inspect wear-test citations

Key Differences & Advantages

Dead even (82 PTS)

Why choose Novablast 4?Buy Novablast 4 if

+1.5 Weight Efficiency

+1.5 Weight Efficiency: Better measured rating in wear-test consensus.

Why choose Glycerin 21?Buy Glycerin 21 if

+1.5 Stability & Support

+1.5 Stability & Support: Better measured rating in wear-test consensus.

The Runner's Pick

Final Decision: Who Buys Which Model?

Side-by-side selection criteria grounded in verified mechanical specs

ASICS

Novablast 4

Choose the Novablast 4 if:

Choose the Novablast 4 if your priority is an ultralight chassis with effortless turnover powered by FF BLAST+ Eco supercritical foam (260g). It is the better match for runners targeting minimizing leg fatigue across late-mile splits over the Glycerin 21's focus on neutral support and surefooted stride containment.

8mm drop · 260g · $140Audit

Brooks

Glycerin 21

Choose the Glycerin 21 if:

Choose the Glycerin 21 if your priority is a secure, planted base with confident guidance powered by Nitrogen-infused DNA LOFT v3 supercritical foam (278g). It is the better match for runners targeting neutral support and surefooted stride containment over the Novablast 4's focus on high-mileage protection and low-impact recovery cruising.

10mm drop · 278g · $160Audit

Dealbreaker Warnings · Who Should Skip These

Critical biomechanical trade-offs to avoid buying the wrong shoe

ASICS Novablast 4

Skip Novablast 4 if you need medial guidance for moderate to severe overpronation; the tall, softly sculpted platform shifts under lateral load.

Brooks Glycerin 21

Skip Glycerin 21 if your typical workout calls for a specialized racer rather than a durable daily trainer.

8-Axis Telemetry Radar

Dead even · 82 PTS

Novablast82vsGlycerin82

Tap any axis node to inspect wear-test citations

🔬 Inspect Granular Lab Specs & Fit Telemetry▼

Fit & Sizing Consensus

Real-world wear-test consensus across runner foot profiles

Novablast 4

Glycerin 21

Sizing LengthMatch

Runs Small

True to Size

Novablast63%Glycerin86%

Runs Large

Novablast 4: True to size(n=19)

Glycerin 21: True to size(n=26)

Toe Box WidthSizing differs

Performance Tight

Standard

Glycerin82%

Wide

Novablast74%

Novablast 4: Roomy / wide toe box(n=18)

Glycerin 21: Standard width(n=22)

Arch SupportSizing differs

Flat / Low

Novablast61%

Neutral Stability

Glycerin76%

High Arch

Novablast 4: Flat / low arch(n=15)

Glycerin 21: Neutral stability / moderate arch(n=18)

ASICS Novablast 4 vs Brooks Glycerin 21 — eight cohort-calibrated radar axes scored one to ten. Delta is Novablast 4 minus Glycerin 21; positive favors Novablast 4. Score provenance: v1.0, data vintage 2026-10-24. Meta-Score weights score band names.
RADAR AXIS	Novablast 4	Glycerin 21	Δ DELTA	COHORT RANK
Cushioning & Softness	9.1	9.0	+0.1 (Novablast 4 higher by 0.1)	#4/18
Energy Return & Bounce	9.0	8.1	+0.9 (Novablast 4 higher by 0.9)	#4/18
Weight Efficiency	8.7	7.2	+1.5 (Novablast 4 higher by 1.5)	#4/18
Stability & Support	6.2	7.7	−1.5 (Glycerin 21 higher by NaN)	#4/18
Traction & Grip	7.6	7.7	−0.1 (Glycerin 21 higher by NaN)	#4/18
Upper Comfort & Lockdown	8.3	8.7	−0.4 (Glycerin 21 higher by NaN)	#4/18
Breathability	8.6	7.5	+1.1 (Novablast 4 higher by 1.1)	#4/18
Durability	7.9	8.3	−0.4 (Glycerin 21 higher by NaN)	#4/18
Meta-Score	82strong	82strong	0.0	Calibrated

The Record · Specification Telemetry

Cohort-relative percentiles and verified technical specs

Novablast 4

Glycerin 21

Weight (US Men's 9)Lighter than 78% of daily trainers

Novablast 4260g

Glycerin 21278g

›ASICS Novablast 4 saves 18g per stride, noticeable after mile 6 of continuous running.

Heel Cushion StackMore underfoot foam than 65% of trainers

Novablast 441.5mm

Glycerin 2138.0mm

›ASICS Novablast 4 delivers 3.5mm more vibration isolation for long recovery efforts than Glycerin 21.

Heel-to-Toe DropΔ 2.0mm

Novablast 48.0mm

Glycerin 2110.0mm

›Glycerin 21's 10mm drop shifts load toward the knees/quads, while Novablast 4's 8mm drop engages the Achilles and calves.

Midsole Foam & Energy ReturnHigher rebound than 92% of tested foams

FF BLAST+ Eco supercritical foam9.0/10

Nitrogen-infused DNA LOFT v3 supercritical foam8.1/10

›FF BLAST+ Eco supercritical foam yields a springier, high-rebound toe-off compared to Nitrogen-infused DNA LOFT v3 supercritical foam's grounded, stable feel.

Outsole Durability & TractionTougher rubber than 87% of road shoes

ASICSGRIP with exposed midsole foam patches7.9/10

RoadTack durable rubber compound8.3/10

›Glycerin 21 utilizes RoadTack durable rubber compound compound formulated for extended 500+ mile abrasive asphalt longevity.

Fit & Sizing Consensus

Real-world wear-test consensus across runner foot profiles

Novablast 4

Glycerin 21

Sizing LengthMatch

Runs Small

True to Size

Novablast63%Glycerin86%

Runs Large

Novablast 4: True to size(n=19)

Glycerin 21: True to size(n=26)

Toe Box WidthSizing differs

Performance Tight

Standard

Glycerin82%

Wide

Novablast74%

Novablast 4: Roomy / wide toe box(n=18)

Glycerin 21: Standard width(n=22)

Arch SupportSizing differs

Flat / Low

Novablast61%

Neutral Stability

Glycerin76%

High Arch

Novablast 4: Flat / low arch(n=15)

Glycerin 21: Neutral stability / moderate arch(n=18)

The Record · Specification Telemetry

Cohort-relative percentiles and verified technical specs

Novablast 4

Glycerin 21

Weight (US Men's 9)Lighter than 78% of daily trainers

Novablast 4260g

Glycerin 21278g

›ASICS Novablast 4 saves 18g per stride, noticeable after mile 6 of continuous running.

Heel Cushion StackMore underfoot foam than 65% of trainers

Novablast 441.5mm

Glycerin 2138.0mm

›ASICS Novablast 4 delivers 3.5mm more vibration isolation for long recovery efforts than Glycerin 21.

Heel-to-Toe DropΔ 2.0mm

Novablast 48.0mm

Glycerin 2110.0mm

›Glycerin 21's 10mm drop shifts load toward the knees/quads, while Novablast 4's 8mm drop engages the Achilles and calves.

Midsole Foam & Energy ReturnHigher rebound than 92% of tested foams

FF BLAST+ Eco supercritical foam9.0/10

Nitrogen-infused DNA LOFT v3 supercritical foam8.1/10

›FF BLAST+ Eco supercritical foam yields a springier, high-rebound toe-off compared to Nitrogen-infused DNA LOFT v3 supercritical foam's grounded, stable feel.

Outsole Durability & TractionTougher rubber than 87% of road shoes

ASICSGRIP with exposed midsole foam patches7.9/10

RoadTack durable rubber compound8.3/10

›Glycerin 21 utilizes RoadTack durable rubber compound compound formulated for extended 500+ mile abrasive asphalt longevity.

ASICS Novablast 4 vs Brooks Glycerin 21 — eight cohort-calibrated radar axes scored one to ten. Delta is Novablast 4 minus Glycerin 21; positive favors Novablast 4. Score provenance: v1.0, data vintage 2026-10-24. Meta-Score weights score band names.
RADAR AXIS	Novablast 4	Glycerin 21	Δ DELTA	COHORT RANK
Cushioning & Softness	9.1	9.0	+0.1 (Novablast 4 higher by 0.1)	#4/18
Energy Return & Bounce	9.0	8.1	+0.9 (Novablast 4 higher by 0.9)	#4/18
Weight Efficiency	8.7	7.2	+1.5 (Novablast 4 higher by 1.5)	#4/18
Stability & Support	6.2	7.7	−1.5 (Glycerin 21 higher by NaN)	#4/18
Traction & Grip	7.6	7.7	−0.1 (Glycerin 21 higher by NaN)	#4/18
Upper Comfort & Lockdown	8.3	8.7	−0.4 (Glycerin 21 higher by NaN)	#4/18
Breathability	8.6	7.5	+1.1 (Novablast 4 higher by 1.1)	#4/18
Durability	7.9	8.3	−0.4 (Glycerin 21 higher by NaN)	#4/18
Meta-Score	82strong	82strong	0.0	Calibrated

The Runner's Pick

Final Decision: Who Buys Which Model?

Side-by-side selection criteria grounded in verified mechanical specs

ASICS

Novablast 4

Choose the Novablast 4 if:

8mm drop · 260g · $140Audit

Brooks

Glycerin 21

Choose the Glycerin 21 if:

10mm drop · 278g · $160Audit

Quiver Overlap

Direct Max Cushion Rivals

2-Shoe Rotation Strategy

Both models occupy the exact same max cushion slot on your shoe rack. Rather than buying both, runner consensus suggests picking the lighter Novablast 4 (260g) for quicker cadence, or the Glycerin 21 for its Nitrogen-infused DNA LOFT v3 supercritical foam ride feel and structure.

Novablast 4 RoleMax Cushion Workhorse

Glycerin 21 RoleAlternative Max Cushion

Explore Related Showdowns

High-traffic benchmark rivalries and cohort showdowns

Novablast 4

Glycerin 21

Dead even · 82 PTS

Why choose Novablast 4?Buy Novablast 4 if

Why choose Glycerin 21?Buy Glycerin 21 if

Final Decision: Who Buys Which Model?

Novablast 4

Choose the Novablast 4 if:

Glycerin 21

Choose the Glycerin 21 if:

Dead even · 82 PTS

Final Decision: Who Buys Which Model?

Novablast 4

Choose the Novablast 4 if:

Glycerin 21

Choose the Glycerin 21 if:

Direct Max Cushion Rivals

Explore Related Showdowns

GEL-CUMULUS 26 vs Novablast 4

GEL-KAYANO 31 vs Novablast 4

Novablast 6 vs Glycerin 21

Glycerin 21 vs Skyward X 2