On IRONMAN and Prohibited Running Shoes
Super shoes are back in the news a bit, as careful eyes have noticed that IRONMAN has recently updated its list of Prohibited Running Shoes. The list, updated about a week ago, is the first time it’s been revised in almost two years.
Without burying the lede, here are the specific shoes that IRONMAN calls out as banned:
- Adidas: Adizero Prime X / Adizero Prime X Strung / Adizero Prime X 2 Strung
- Asics: SUPERBLAST/Novablast 4/Nova Blast 5
- New Balance: FuelCell SuperComp Trainer
- Saucony: Kinvara Pro
Famously, Patrick Lange wore the Adidas Prime X to the fastest IM run split in Israel in 2022, and the prototype version of Prime X 2 to the fastest full distance run split ever in Challenge Roth in 2023.
All of these shoes violate specific provisions of World Athletics rules regarding running shoes. World Athletics announced their revised ruleset for running shoes in 2021, following the continual shattering of records in part influenced by the technological gains that carbon plated race shoes provide. The gist of these rules is simple: shoes cannot feature a midsole stack height of greater than 40 millimeters, measured “at the center of the heel and forefoot,” deemed to be 12% and 75% of the total midsole length, of a men’s size 42 EU (men’s US size 9) sample.
Shoes also are generally limited to a single carbon fiber plate — an exception exists if the plate is broken up into multiple pieces, but it has to exist “in a single plane” and calls out that plates can’t stack on top of one another.
IRONMAN decided to add the World Athletics language to their rulebook following the 2022 IRONMAN World Championship. There, Gustav Iden utilized a taller stack prototype of On’s Cloudboom Echo to great effect, running a 2:36:14 marathon to victory. The shoe would have been deemed illegal under the World Athletics guidelines — first, for not being commercially available; prototypes are only legal after certification with WA. And second, for violating the stack height limits.
IRONMAN’s rulebook is pretty clear on this subject. Rule 6.02 covers illegal equipment, with subsection e handling run shoes. The rule is pretty darn clear in its language:
IRONMAN adheres to World Athletics’ Shoe Regulations applicable to road events for all IRONMAN and IRONMAN 70.3 Events, including the IRONMAN World Championship and the IRONMAN 70.3 World Championship. For the avoidance of doubt: Running shoes with a stack height sole thickness (as defined in World Athletics: Athletic Shoe Regulations 10.3-10.5) of greater than 40mm are prohibited and will result in disqualification. Shoes containing more than one plate rigid structure (as defined in World Athletics; Athletic Shoe regulation 10.6) are prohibited and will result in disqualification.
It essentially codifies rules that were effectively silent prior to 2023. Remember, as we discussed with Jimmy Riccitello on our podcast last year, where the IRONMAN rulebook is silent, it relies on World Triathlon’s rules. And if that is silent, then the rules of the individual sport apply — World Aquatics for swim conduct, the UCI for cycling, and World Athletics for running.
But that’s also where we start to get murky today — because technically, by IRONMAN’s own rulebook, its list of Prohibited Running Shoes is not exhaustive. Instead, the Prohibited List is just a starting point of specific models that run afoul of the World Athletics regulations. But there are dozens of other shoes that also do not pass muster; for example, there’s HOKA’s Skyward X, or the Brooks Glycerin Max I reviewed last week, which both exceed the stack height rule. Yet they are curiously absent from the Prohibited List.
What gets more complicated are shoes that might be legal, but do not appear on an approved list. World Athletics maintains a database with hundreds of shoes that are approved for competition. Fifty-three different brands are represented on that list. The PDF version of this list is what IRONMAN links to specifically within their rulebook to search for approved shoes. Yet a look through the list shows that gaps remain in the process. Let’s take HOKA as an example. There are 24 different models posted as approved, from the Rocket X2 to the Clifton 7. But the newer models of Bondi are curiously absent; just the two generation old Bondi 7 is listed as approved.
It’s worse for other manufacturers, as it appears that they have focused their efforts on only having their key racing models approved by World Athletics. Adidas, for instance, only has their Adizero line of racing models listed (outside of the prototype next generation Takumi Sen). For Brooks, the only approved non-track spikes are various Hyperion and Hyperion Elite models. Does that make the regular Ghost, or Glycerin, illegal? No, but it makes for a massive gray area for athletes; how can you be sure that your shoe is actually permitted when IRONMAN maintains a small list of Prohibited Shoes, but its own rules point you to a list of approved ones and your shoe isn’t there?
IRONMAN can choose, by my estimation, two paths to make this more clear for athletes. Either a.), they follow the World Athletics approval list to the letter, and everything else is banned, or b.) they need to be more robust in their own testing and approval process if they plan on maintaining their own prohibited list. Either of these options create problems. With the former, you are effectively eliminating many of the “training” shoes that so many choose to race long-distance triathlon in (is it really an IRONMAN if nobody is wearing a Bondi?). With the latter, it means IRONMAN has to invest in its own testing protocol. And heaven forbid if their measurement is somehow different than World Athletics.
It is ultimately a situation crying for clarity. (Jimmy…podcast?)
Same basic list it has been since the last revision. (It’s really just shoes banned by World Athletics, and then trickles down to World Triathlon, and then to IM).
There are plenty of other shoes that technically fail the WA test (I just reviewed one for the front page), but because I don’t think anybody at the front of the field is considering wearing it as a race shoe…they don’t get declared.
Figure this might be easier: the full list of legal shoes (as long as it’s approved under the Road & Race Walking category, you’re fine). Full list | LIST OF APPROVED ATHLETIC SHOES
I’m expecting an upcoming change in the rules in the next couple years. Mizuno has exploited the specifics of the measurement and I don’t see why other companies wouldn’t do the same. They’ll probably just change it to define max stack height at any point perpendicular to the insole/outsole.
They measure stack height at 12% the length of the shoe with the heel on the ground, so shoes like this are legal despite a 60mm stack height. (tbf I snagged a pair and they are brilliant, if you like high stack shoes)
I’m just going to run in my Skyward X this year until they specifically by name ban it.
does IM say that it follows the world athletics shoe rules? which would mean anything above 40mm in shoe height? also, i’m confused by the world athletics rules, as to who they apply to. my cursory read says that they apply to those who are in a competition generating world athletics points.
““Applicable Competition” means a competition that holds a permit issued by either World Athletics, an Area Association or a National Federation where all relevant World Athletics’ Rules and Regulations are complied with and consequently at which World Ranking Points and holding a permit issued by their National Federation, in addition the National Federation must endorse the competition as being valid for World Athletics’ statistical and results purposes.”
there’s a lot of “ands” in there. not “ors”.
so, in a typical road race is this ruleset relevant? is it the same for pros and AGers?
With regard to IRONMAN: yep. Rule 6.02(e) on Prohibited Equipment:
A list of pre-approved running shoes can be found here. Generally, IRONMAN
adheres to World Athletics’ Shoe Regulations applicable to road events for all
IRONMAN and IRONMAN 70.3 Events, including the IRONMAN World Championship
and the IRONMAN 70.3 World Championship. For the avoidance of doubt: Running
shoes with a stack height sole thickness (as defined in World Athletics: Athletic Shoe
Regulations 10.3-10.5) of greater than 40mm are prohibited and will result in
disqualification. Shoes containing more than one plate rigid structure (as defined in
World Athletics; Athletic Shoe regulation 10.6) are prohibited and will result in
disqualification. Customized shoes, as defined in the World Athletics’ Shoe
Regulations, are permitted to be worn in competitions following approval from the
World Triathlon Technical Committee. Development shoes, as defined in the World
Athletics’ Shoe Regulations, can be used in all Events (including World
Championships) with the conditions that:
(i) the specific shoe is already on the list of Shoes Approved by World Athletics
as a development shoe;
(ii) the Event where the shoes to be used is held within the approved dates as
indicated on the list of Shoes Approved by World Athletics; and
(iii) the shoe manufacturer or the athlete must submit the request to the World
Triathlon Technical Committee to be able to use the development shoes.
Athletes are subject to random shoe control before, during, or after any Race. For
any shoe that cannot be identified, each piece of information (and maybe the shoe
itself) will be required to be sent to the World Triathlon headquarters for
verification within 7 days after the Race it was worn. In the official results, the
athletes under shoe review will have the note ‘Result Under Review’ added to the
results footer notes. If the shoe is confirmed as legal, the note will be removed. In
any different case, the athlete will be disqualified.
For your typical, average, run of the mill road race? Depends on whether it is a USATF sanctioned event or not. The vast majority aren’t.
Edit to add: the link described in the rulebook above goes to the PDF version of the approved list I linked upthread.
this is a question i have. that’s a really nice shoe. but i don’t see how it’s legal in IM competition based on the rule section ryan just reprinted above.
IM made this needlessly complicated by supplementing their actual rule with a non-exhaustive list of prohibited shoes.
Exactly.
The easiest way to have done this was to just link to the list of shoes approved for competition versus trying to come up with a banned list.
But they started this thing with their non-exhaustive list of prohibited wetsuits back in the day, which then created the whole loophole that resulted in that Daniela Ryf wetsuit fiasco from a couple years back.
But wouldn’t listing almost every shoe ever produced any where in the world be unmanageable?
See post #3 for an already made list. There aren’t that many companies making running shoes and those companies don’t make that may models, and very few of those are anywhere close to the max height. Probably 100 shoe models/year that actually need to be measured
Dan, it’s not legal but until they specifically ban shoes by name it’s fair game as far as I’m concerned. As was pointed out they made a rule and then they made a list. That was just stupid. They set some sort of precedent with the list and it’s their job to now update that list. If they’re two years behind that’s on them for starting this problem in the first place.
Pre-2016 shoes are all grandfathered in.
Anything more recent than that, if you want your athletes to wear it in a WA-following event, you need to submit it for testing, approval, and publication on that list.
With regard to the Skyward X, as @Slowman and @The_GMAN_Retired are in: it’s not on the approved list, ergo, it is technically illegal for any World Triathlon or IM branded event. But for your average road race? Nobody cares. And I doubt that unless you won your age group or qualified for a worlds slot, anybody would care about wearing a Skyward X (or a Glycerin Max or something else) during one.
And, yeah, this is silly to have a banned list when you could just roll through the approved list. Shoe not there? It’s not allowed.
Disagree. Unenforced, maybe, but not fair game. A pro winning Kona on these shoes would be a big problem.
Hoka Skyward is greater than 40mm and not on the list. Nowhere in the actual rulebook does it say that shoes NOT listed are prohibited are allowed. They would probably define this as “Development shoe” which would be subject to testing
No, the “dev shoe” is a specific call out thing. It still shows up on the list (see, e.g., multiple versions of the new Hyperion Elite, which are legal until the retail version hit shelves).