Why You Don't Need to Worry About Wearing 'Illegal' Running Shoes for Your Race
The Myth of the 'Illegal' Running Shoe
For the vast majority of runners, the term 'illegal' running shoe is nothing more than a catchy phrase thrown around on social media. But here's where it gets controversial: despite the buzz, you don't need to worry about being disqualified for wearing these so-called 'illegal' shoes. So, let's dive into the nitty-gritty and separate fact from fiction.
The Running Shoe Boom
Over the past half-decade, running shoes have exploded in popularity, both literally and figuratively. On one hand, the running boom has made trainers more popular than ever. On the other, they're literally getting taller. With each new model, midsoles have grown in the name of (alleged) improved efficiency. The 'illegal' shoe emerges from this category.
What Makes a Shoe 'Illegal'?
These would be the laws of the governing body for athletics, World Athletics. Its guidelines for road races – covering everything from mile events up to ultramarathons – state that footwear can have a sole height no greater than 40mm and have only one 'rigid structure', like carbon plates or rods. Running shoe brands have mostly obeyed these guidelines for their premium racing products.
The Reality of 'Illegal' Shoes
However, they've totally ignored the rules for other models like humble daily trainers, which, in recent years, really have beefed up – and it's these shoes that many, many runners are wearing. According to Strava's Year in Sport Report for 2025, these were the top three pairs of running shoes logged by users that year, along with each shoe's stack height:
- Asics Novablast – 41.5mm
- Nike Pegasus – 37mm
- Hoka Clifton – 42mm
All are daily trainers – and you'll notice that only one is below the 'legal' competitive limit. The 'illegal' shoes aren't contraband, though. They're the beloved trainers that your uncle wears on a jog with his boys. Maybe you wear them, too. And that's fine.
The Reality of Race Disqualifications
Whether you're lacing up for a local 5K or an Abbott World Major Marathons event, the likelihood that you'll be disqualified for wearing 'illegal' shoes is tiny. I ran the New York Half Marathon last year wearing the Asics Superblast 2 (45 mm) and, in 2024, I also took on the Big Sur Marathon with a group outfitted in the Hoka Skyward X (48 mm), without any issues. I know plenty of runners who can say the same. In practice, these rules are meant to apply to elite competitors – they even run in different heats. These runners are also drug tested, which is another thing that normal participants don't have to worry about.
The Importance of Smart Shoe Selection
Just in case, I checked in with New York Road Runners (NYRR) – the organization behind the New York City Marathon (and the half marathon that I ran last year). An NYRR rep confirmed that the organization does apply World Athletics rules to its major events, but that it also considers violations on a case-by-case basis. Last year, NYRR didn't disqualify anyone due to these rules.
The Bottom Line
Even though I think that the 'illegal' terminology is mostly social media hype, it doesn't mean that you shouldn't be smart about the shoes that you're wearing. High stacks can be unstable and affect your running gait – and they come with a learning curve. 'It's an adjustment, like getting braces on your teeth,' says Dr Mark Mendeszoon, a board-certified podiatrist and surgeon at Precision Orthopaedic Specialties in Ohio. 'You have to learn slowly.'
Mendeszoon recommends breaking in new shoes by wearing them around the house, then focusing on cross-training and recovery after you hit the road. 'With all that foam and stack height, it's going to kind of shorten your Achilles,' he says. 'So work on Achilles flexibility and stretching afterward.'
Basically, if you're somebody who needs to worry about 'illegal' shoes, you likely already know all this. And you're probably not a runfluencer. So, whether you're lacing up for a local 5K or an Abbott World Major Marathons event, don't stress about the 'illegal' shoes. Just focus on enjoying the run and pushing your limits.
