WSJ: The newest marathon super shoes are here and seem AMAZING. One weighs less than 4 ounces, one doesn't have laces.

Shoes without laces would be an absolute deal-killer for me. How would you adjust the fit? I use elastic laces and I still adjust the snugness depending on the thickness of the sock and the type of workout I'm doing that day.

Sorry down voted when for sure wanted to upvote 8x

the heavier shoe may be better because your legs and feet will be destroyed over the marathon distance. I don't think I've heard of an elite time run in anything lighter than the streak lt. Well there was Bikila, but he grew up running barefoot.

God the Streak LT truly was a great one.

Interesting question here. In the sports med/shoe world, we know a decent amount about weight, although less about cushioning. It's usually cited that weight-wise, each 100g of shoe weight increases VO2 at a given pace increases by at least 1% (PMID: 22367745).

Craig Richards and Thomas Hollowell claim in their book for barefoot running that BF running is more efficient, largely due to the mass of the shoe being nil. BUT, when BF running, you tend to over-mid or forefoot strike, which can negatively impact economy. This makes interpretation messy.

When looking at how the same individuals respond to barefoot vs shoe vs weighted shoe, we know two main things.

1) VO2 is 3-4% lower (more efficient) at a given submax pace (think mara pace) in shoe running versus barefoot, despite weight being higher in shoe condition. This was largely attributed to a 3.3% increased stride length in shoes vs barefoot. (PMID 22367745).
2) As you said rojo, indeed when shoes are matched for mass, a more cushioned shoe reduces VO2 at a given pace (PMID: 6654550). When barefoot running, the cushioning requires eccentric (and some concentric) muscle activation, increasing VO2 just to act as a cushion.

Overall, it's messy, and there is no easy answer. There is some goldilocks zone between cushioning and mass, and this is the million dollar question. It also gets messier when you consider individual biomechanics. Beamish versus a heel-striker will respond very differently to different shoes.

100g of weight is approximately equal to 1% of running economy benefit. So 3.4 ounces vs 7 ounces is basically right on 1% of contributing benefit (as 3.6 ounces is 102g).

But everything in this game is a compromise and weight is not the only factor that leads to performance.

For example you had the Mizuno Universe back in the late 90s which was only 2.8 ounces and that shoe amounted to simply an "abrasion protector" for your feet with maybe 8mm of firm EVA cushioning at absolute most. This shoe was insanely light and the lack of cushioning meant it was extremely efficient as a medium between your foot and the ground in terms of ground force - no cushion, no deflection = very efficient ground force scenario. The tradeoff was that zero cushion means your lower legs start taking the beating from the gun with no respite and we know that lower leg shock/impact/vibration is a massive contributor to fatigue especially in longer races.

A shoe like the Adios pro evo 3 gives up a around half an ounce to an old school racer but with 35+mm of cushioning it does a great job of protecting lower leg muscles from fatigue which is why the hallmarks of supershoes has been 1) massively improved performance in the last 6-8km of marathons and 2) not feeling utterly wrecked the next day. But the trade-off here is that despite the super low density of the foams being used, those 35mm+ platforms represent a considerable medium for your energy/force to pass through on the way to the ground. So the trade off is that while your cushioning is incredible and saves your legs, that process of a considerable chunk of foam compressing and rebounding (and the "rebounding" does not generate energy or force which is a massive misconception and not difficult to resolve when you really think about it), does make your ground force potential lower. Not by a ton, but something when you think about how many impacts you'll make in a marathon.

That explains why the Nike Alphafly is almost twice the weight of a Evo pro 3 etc but probably just as effective a race shoe. The FF (with plates, airbags, and all the crap that sticks it together) represents a firmer and ironically more efficient force transfer medium. So you trade off weight for that (and vice versa with the Adios and other super light shoes like the Metaspeed Ray).

So weight matters, but so do a lot of other things.

Why do you use the word “as” so much?

Already back in the -80s my racing shoes Onitsuka Tiger ( nowadays Asics ) were light as leafs... but of course not the same cushoning as todays supershoes.

I just loved my Onitsuka Tigers and even trained in them often because they felt so light and smooth. 🧙‍♂️🏃🇸🇪

There's a reason all the shoes were really minimalist until super shoes came around. All else being equal, lighter is better because it takes less energy to move a lighter thing around.

When super shoes came around they were much heavier and we went in the maximalist direction because the battle was "heavy super shoe" vs "light shoe with no carbon plate," and the former was obviously better.

But as the technology has gotten better, we are able to go back in the lighter shoe direction again while making less compromises on cushioning and plate.

We can imagine different shoes as points on a Pareto frontier of "cushioning" vs "plate" vs "weight." Where if you want less weight you have to compromise on something. Or if you want better cushioning you need to compromise on weight. It's a tradeoff and depends on personal preference.

Bump

I guess those new shoes worked

According to Jack Daniels, for a show every ounce is worth 0.83 sec per mile with the caveat that lighter shoes are usually less protective (or everyone would be running barefoot). The new Evo 3 is 96 gram so that's worth about 1-2 mins compared to the old supershoes, if they somehow manage to be just as protective.

I didn’t think that small reduction in weight would matter; were Sawe and Kejelcha wearing them today?

except it's more than 100 gram PER shoe lighter than the Alphafly 3. It's essentially the difference between a bulky trainer and a racing flat!

Still not as light as bare feet. So what are these shoes providing that makes such a difference?

This was Mantz.

Guaranteed this will trend people to buy the lightest shoes possible.

Lose a few pounds? no that's asking too much!

The same principles have always existed in sports like cycling. Be as light as possible, buy lighter gear = race faster. However, why lose 10lbs when you can gleefully spend $15,000 on a new bice with the latest tech.