The Flow 2 rides on Altra’s EGO™ P35 midsole foam, a blend designed for efficiency and responsiveness rather than plush softness. Both Abby and Brian found it to be smooth, firm, and stable underfoot, striking a nice middle ground between comfort and performance.
Abby described the foam as “fun, bouncy, and protective,” and noted that the 4mm drop and subtle rocker shape encourage a natural, quick-cadence stride. She loved how it supported midfoot striking during tempo efforts but admitted she saw early compression marks forming under her toes—hinting that durability may not match some of the higher-end foams on the market.
Brian echoed that the midsole feels firm and fast, particularly during shorter runs, workouts, or races up to 10K. He appreciated the stability and ground feel but found it less suited for long runs, where he preferred a bit more cushion.
“The midsole foam is fun, bouncy, and protective. It’s soft for an EVA foam, but it’s more responsive. I didn’t feel like the rocker shape was too dramatic—it feels natural with my individual mechanics.”
In short, the Flow 2’s midsole delivers a controlled, energetic ride that rewards efficiency and turnover. It’s best suited for runners who like a connected feel on the road and don’t mind trading a bit of plushness for speed and precision.