Teen Kiwi Running Star Sam Ruthe Breaks Under-18 Mile World Record

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When New Zealand runner Sam Ruthe crossed the line to break the under-18 indoor mile world record last week at Boston University, he became the 11th fastest indoor miler of all time. By clocking the distance in 3 minutes and 48.88 seconds, he also became the youngest male to break the 3:50 mark in the mile - at just 16 years and 294 days old. This unbelievable performance was Ruthe's first time on an indoor (banked) track, and came after a 50-hour travel time from his hometown of Tauranga to Boston, and subsequent jetlag.

Why it matters

Ruthe's record-breaking run is the latest example of an emerging trend in middle-distance running, where teenagers are increasingly comfortable competing at the world-class level. This raises questions about how these young athletes are able to achieve such high levels of performance at such a young age, beyond just early specialization or high training volumes.

The details

Research suggests the key factors behind the rise of young middle-distance stars like Ruthe and Australia's Cam Myers (who recently set a world under-20 indoor mile record) are running economy and biomechanical efficiency. Factors like effective force production, optimal limb proportions, and the use of "elastic" energy in the Achilles tendon allow these athletes to run at high speeds with less muscular effort. Advancements in shoe technology, particularly carbon-plate designs and improved midsole foams, have also played a role in enhancing performance.

• On February 11, 2026, Sam Ruthe broke the under-18 indoor mile world record at Boston University.
• Ruthe achieved this feat at 16 years and 294 days old.

What’s next

Ruthe has been announced to join fellow young stars Cam Myers and Cole Hocker in the prestigious Bowerman Mile at the 2026 Prefontaine Classic in July.