Lighter than a bar of soap - the shoes worn to shatter marathon record
In recent years, major improvements in marathon times have been made thanks to the introduction of carbon-plated midsoles. The latest version also integrates carbon more fully into the design. And in the search for marginal gains, the redesign and reduction in weight have led to an increase in running economy according to the manufacturer.
"At that level, every detail really matters – we were measuring things down to the nearest nanogram," Adidas' VP of running, Patrick Nava, said of the design process. "It was a long process, but it's led to something we believe genuinely changes what a race-day shoe can feel like. " For the casual runner taking advantage of the technology comes at a financial cost though.
A wider release is expected later in the year following on from the initial limited launch, but the shoes are currently priced at £450. When Kipchoge broke the sub-two hour mark wearing the Nike Alphaflys in 2019, the American sportswear brand was undoubtedly the market leader. Its reputation was enhanced further in 2023, when Kiptum set the previous world record in Chicago wearing the Nike Alphafly 3s.
But just like in racing, boundaries are there to be pushed. With Sunday's results, Adidas can now boast that the fastest man and woman to ever run a marathon both wore their shoes. But the battle never stops between the biggest sportswear brands, particularly given the increased popularity in running in recent years.
Rivals brands including Asics, Saucony, Hoka, Brooks, and New Balance were also sported by many of Sunday's marathon competitors. Governing bodies have been trying to keep pace with advances in footwear technology over recent years and World Athletics updated its regulations in January 2022. It released an 18-page document , external , which stated shoes could not be used unless they were available to "any athletes participating in applicable competitions".