Head-to-Head
Glycerin FlexvsAero Glide 4
The Glycerin Flex and Aero Glide 4 are both daily trainer shoes built for road running. The Glycerin Flex retails for $170 while the Aero Glide 4 comes in at $160 — a $10 difference. The Aero Glide 4 is the lighter shoe at 9.0 oz versus 9.1 oz for the Glycerin Flex. In our ratings, the Aero Glide 4 edges out the Glycerin Flex — 9.0/10 versus 8.0/10.
| Rating | 8.0 / 10 | 9.0 / 10✓ | |
| Price | $170 | $160✓ | |
| Weight | 9.1 oz | 9.0 oz✓ | |
| Category | Daily Trainer | Daily Trainer | |
| Terrain | Road | Road | |
| Cushion | Medium | High | |
| Softness | Balanced | Balanced | |
| Drop | Medium | Medium | |
| Drop (mm) | 6 mm | 8 mm | |
| Stack | 36 mm | 42 mm | |
| Stability | Neutral | Neutral | |
| Fit | Narrow | Medium | |
| Energy Return | Low | High✓ | |
| Breathability | Medium | Medium | |
| Traction | High | High | |
| Shock Absorption | High | High | |
| Durability | Good | Good |
