Super Shoes for Ultramarathons?

Should you wear a super shoe for an ultra? Unless unless you are an elite runner, probably not.

What is a super shoe?

I will consider a super shoe to be extremely light, bouncy, and stiff. The use of a new type of foam called PEBA or Pebax is a key part of a super shoe. This foam is far lighter and far bouncier than previous foams. It allows for a midsole that is much thicker without any weight penalty. The bounciness returns a lot more energy than previous foams. This is then combined with a full length carbon fibre plate that adds stiffness and springiness. This combination produces a shoe that can be more than 4% more efficient than previous shoes.

Super shoes and running pace

My experience is that you don't get the benefits of a super shoe when running slowly. For me, there is a transition around 8 minutes per mile (5 minutes per kilometre) where a super shoe comes into its own. At a slower speed, a super shoe doesn't seem to give much benefit, and most people in most ultra races are running slower than that.

Super shoes and running surface

The Super shoe technology only seems to work on paved surface is. On trails or soft surfaces, you don't seem to get the energy return. I had a pair of running shoes with PEBA foam (but no Carbon fibre plate) resoled with a trail outsole. I found that there was no benefit on the trails from the advanced foam, though on runs change between road and trail there was still a worthwhile benefit on the road sections.

Super shoes and ankle stress

I've found the thick midsole and squishy foam make super shoes unstable when walking or running slowly. Unless you're a fast enough runner to be keeping up and continual brisk run, a super shoe probably won't help you in an ultra.

Super shoes and fatigue

Towards the end of 30 mile (50 km) runs I've found that super shoes don't seem to give me the same benefit. I suspect this is mostly because I've adapted to the Super shoe so that it feels normal. Most of my running is not done in super shoes, so i suspect i am still getting the benefit, I'm just not feeling it the same way.

Conclusion

I feel that for most runners, a super shoe is not going to help on an ultra. If you're a fast runner on a road ultra, they might be an advantage. They might also help on a trail ultra that finishes on a road, but again, only if you are quite fast.