Fit

Altra continues its proprietary foot-shaped last in the One v3 which is wider in the midfoot and forefoot than traditional manufacturers. The midfoot secures down well, although some testers had issues with the laces coming loose (and also being way too long). One recurring issue was some slipping in the heel area, even with the laces secured tightly.

Comfort

The new TPU overlays provide added structure to the upper but also decrease the ventilation and breathability of this shoe in warm conditions. Additionally, the overlays across the top of the toe box lie at flexion points and caused some irritation on top of the toes for a few testers.

Responsiveness

Altra’s updated Innerflex midsole is designed firmer to provide a more responsive and less cushioned feel. Stack heights of the midsole increased from 20mm on the One 2.5 to 23mm on this model to compensate for the firmer landing – but if you’re accustomed to Altra’s traditional cushioning platform, the new One v3 will initially feel harder and clunkier. When using a midfoot landing, the midsole material still allows a reasonable heel kick to continue the forward stride with good energy return. The updated rubber coverage in the One v3 outsole provides a definite improvement in traction and push off compared to the 2.5.

Ride Quality

With a low platform and firm midsole, the One v3 feels more like a road racing flat than a trainer. Landings are smooth and the cushioning is evenly distributed, which allows the neutral runner’s natural gait to take over. Over long distances, the firmer midsole delivers consistent responsiveness, but for shorter cruises you may miss the cushiness. The highly flexible midfoot is great for natural biomechanics but loses some energy return.

Speed

This is closely interrelated with fit: our testers who secured the fit down were able to do 5-mile tempo runs at sub-6 pace, and the lightweight One v3 had no problems keeping up. Those who had issues with heel slipping found it hard to maintain a quick rhythm.