Preparing for my last marathon I used my older pair of super shoes for all my specific sessions and long runs. Probably put 300 miles on a pair of Next %'s that already had 100+ miles on them.
The foam generally felt fine, but my issues was the outsole...it tended to have spots that "pitted out" and exposed some foam, but performance wise I didn't notice it while running.
Anyone retiring super shoes after 2 marathons is either a PRO, rich or ignorant.
Geoff Burns was on The Real Science of Sport Podcast in June of 2024. I recall him talking about training in super shoes. If I remember correctly, he said he puts lots if miles on each pair of super shoes and trains in super shoes more than most people. He also said that he believes that because of the rebound ability of the foam they might actually last longer than other shoes (probably EVA foams??).
I remember listening to this too! Basically that the super foams are much more resilient (the technical term) and you can basically wear them till the outsoles disintegrate! They do however lose some of their magic. Personally I race in them for up to 200 miles, and then train in them till they disintegrate.
The new PEBA foams last longer than EVA. I’ve done benchtop materials testing on new VaporFly Next% and ones with 500 km (300+ miles) and the compliance (softness) and resilience (energy return) were very very close to the original values. The energy return dropped from ~85% to ~83%, still dramatically higher than old foams. The compliance was also nearly identical.
For this reason, among others, I’ve switched to doing a lot of my own training in super shoes. The integrity of the shoes seems more predictable, especially as these new polymers are more robust to temperature changes.
The life-limiter on the shoes actually seems to be the physical integrity of the foam, where the abrasion from the road rips it up (unevenly for most people, ie, on the lateral or medial portions), as most have only minimal rubber on the bottom for weight. I typically send my super shoes to the graveyard when the foam gets ripped up enough to feel like the shoe isn’t level anymore on the ground.
We wrote about this in a paper that was just published (pg. 3, “AFT Foam Durability”). It’s still open access, so feel free to check it out:
I wear a pair almost exclusively for racing for about 100-125 miles, then it becomes my workout shoe. It might take 6-8 months to get that many miles on them from races. Probably doing 400-500 miles worth of workouts in that time period. So I guess each pair will get 500-700 miles, and they are a bit beat up by the end up but they're still fine to run in. The foam and existence of the plate makes it a bit different from a normal trainer, when you run a normal trainer that long you feel like there's nothing left between your foot and the road and you can basically feel rocks straight through the foam
The modern era of running shoes began in the 1960s with the introduction of simple polymer midsole foams, and it ended in the late 2010s with the introduction of advanced footwear technology (AFT). AFT is characterized by hig...
The new PEBA foams last longer than EVA. I’ve done benchtop materials testing on new VaporFly Next% and ones with 500 km (300+ miles) and the compliance (softness) and resilience (energy return) were very very close to the original values. The energy return dropped from ~85% to ~83%, still dramatically higher than old foams. The compliance was also nearly identical.
For this reason, among others, I’ve switched to doing a lot of my own training in super shoes. The integrity of the shoes seems more predictable, especially as these new polymers are more robust to temperature changes.
The life-limiter on the shoes actually seems to be the physical integrity of the foam, where the abrasion from the road rips it up (unevenly for most people, ie, on the lateral or medial portions), as most have only minimal rubber on the bottom for weight. I typically send my super shoes to the graveyard when the foam gets ripped up enough to feel like the shoe isn’t level anymore on the ground.
We wrote about this in a paper that was just published (pg. 3, “AFT Foam Durability”). It’s still open access, so feel free to check it out:
Hey, this is such an interesting read! Thanks for sending the paper. However, it finds different results from a research made in Spain, which found that PEBA foams get even down to EVA values in resiliency after ~300 miles: https://onlinelibrary.wiley.com/doi/10.1111/sms.14526 worth taking a look and I'll be happy to hear your thoughts.
My 2 cents on this, as someone that has used +15 pairs of PEBA-based running shoes for +300-500 miles, is that I tend to find PEBA less resilient—certainly more than 2%—after 200-300 miles. But it could also be just less compliance, I don't really know.
It was very noticeable with the Invincible 1s, which a brand new pair felt amazing when compared to a 400-mile pair. But again, just my N=1... and I also believe that a 400-mile PEBA returns way more energy than a 0-mile EVA shoe.
Many of the PEBA-based superfoams are well known to be super durable, and there's no reason to believe the plate wears out. The Metaspeed series uses the same foam as the Superblast and the durability of the Superblast is legendary. It may be the case that their resilience/bounciness diminishes quickly to a degree measurable by a machine or perceptible by an elite athlete using them for a maximal experience, but that doesn't mean they'd quickly become unsuitable for use in training. I haven't listened to the interview with Clayton Young yet, but FWIW I know several very good runners (including a couple of OT qualifiers) who put tons of miles on one pair of Vaporflys in workouts but use a fresh pair for racing. With the major exception of seeing the upper split open and outsole peel off after probably <50 miles on somebody's pair of Pro Evo's I've seen no other convincing evidence that supershoes degrade in a way that would be meaningful for use in training any faster than regular old EVA. If anything, the opposite seems more nearly true.
Many of the PEBA-based superfoams are well known to be super durable, and there's no reason to believe the plate wears out. The Metaspeed series uses the same foam as the Superblast and the durability of the Superblast is legendary. It may be the case that their resilience/bounciness diminishes quickly to a degree measurable by a machine or perceptible by an elite athlete using them for a maximal experience, but that doesn't mean they'd quickly become unsuitable for use in training. I haven't listened to the interview with Clayton Young yet, but FWIW I know several very good runners (including a couple of OT qualifiers) who put tons of miles on one pair of Vaporflys in workouts but use a fresh pair for racing. With the major exception of seeing the upper split open and outsole peel off after probably <50 miles on somebody's pair of Pro Evo's I've seen no other convincing evidence that supershoes degrade in a way that would be meaningful for use in training any faster than regular old EVA. If anything, the opposite seems more nearly true.
The SB is my all-time favourite shoe, and I have to say that FF Turbo holds impressively well over time—maybe second best to Lightstrike Pro—but FF Blast+ does not. At least I really can feel how after 250-300 miles, Blast is dead, and it definitely makes it less appealing. Of course it's a perfectly usable shoe still and I can see the Superblast going +600 miles easily.
However, the PEBA midsole experienced greater wear over 450 km and worsened RE compared with the new PEBA condition. While for the shoes with an EVA midsole, RE was not affected when the shoe was worn for 450 km.
Vaporflys lost their racing pop around 200km but still useful for training up to 600km
Alphafly: never great for racing, worse than the Vaporflys for me. However, I have a pair of the Alphafly V1 that I've put 1000km on and they're still good, better than an equivalent trainer like the Tempo Next % or Endorphin Speed. Great durability.
Adios Pro 2: not as good as the Vaporflys or Alphafly for racing but a solid training shoe. But, it is basically completely dead after 280km. It feels like dead rubber at this point.
My takeaway is that if you want a supershoe for training, the Alphafly is the winner by far, more bang for your buck. But I still race in the Vaporfly as it feels best for me.
