For most individuals, the term "illegal" shoe simply doesn't apply. Yet, social media is rife with influencers using this term in a sensational manner. One particular creator has even launched a video series comparing these so-called "illegal" shoes with others deemed "legal."
There's a peculiar undertone to this narrative that is hard to ignore.
Let's delve into the details. The running shoe market has experienced remarkable growth recently, both in popularity and in design. The surge in running culture has led to sneakers becoming more popular than ever, while the technology behind them has evolved, resulting in taller midsoles aimed at enhancing performance.
The shoes labeled as "illegal" typically stem from regulations set by World Athletics, the governing body for track and field. Their guidelines specify that for road races, footwear must have a sole height not exceeding 40 millimeters and can only incorporate one rigid element, such as carbon plates.
Most sneaker brands have adhered to these rules for their top-tier racing models, but many daily trainers have also increased in height. It's these trainers that countless runners are choosing.
According to the Strava Year in Sport Report for 2025, the most logged running shoes among users include:
- ASICS Novablast (41.5 mm)
- Nike Pegasus (37 mm)
- Hoka Clifton (42 mm)
Interestingly, only one of these models stays within the "legal" limit. The so-called "illegal" shoes are simply the comfortable trainers that many casual runners wear. And that's perfectly acceptable.
Even if you're preparing for a local 5K or a major marathon, the chances of being disqualified for wearing "illegal" shoes are minimal. I personally participated in the New York Half Marathon last year with the ASICS Superblast 2 (45 mm) and faced no issues. Many runners can share similar experiences. These regulations primarily target elite competitors, who participate in separate heats and undergo drug testing--concerns that regular participants need not worry about.
To clarify, I reached out to the New York Road Runners (NYRR), the organization responsible for the New York City Marathon. They confirmed that while they follow World Athletics rules, they evaluate violations individually and noted that no one was disqualified last year due to these regulations.
While professional athletes have faced disqualifications for shoe-related rule breaches, events like triathlons and Ironman competitions tend to enforce stricter rules.
Despite the hype around the term "illegal," it's essential to make informed choices about your footwear. High-stacked shoes can be unstable and may alter your running form, requiring a period of adjustment.
"It's a learning process--similar to getting braces," advises Dr. Mark Mendeszoon, a certified podiatrist. "You need to ease into it."
He suggests gradually breaking in new shoes, starting by wearing them at home, and focusing on cross-training and recovery after runs. "With all that foam and height, it can shorten your Achilles tendon," he adds, emphasizing the importance of flexibility and stretching.
Ultimately, if you're someone concerned about "illegal" shoes, you likely already know this, and you probably aren't a runfluencer.
Our Recommended "Illegal" Shoes
Rest assured, wearing these shoes won't land you in trouble as a regular runner. Explore these top picks with sole heights of 41 mm and above, but remember to heed Mendeszoon's advice and prepare yourself accordingly.