CurraNZ Marathoner's big London goal catches attention of Runners World

At an age when most runners are accepting decline, Mark Kleanthous is doing the opposite — and Runner’s World took notice.

The Leighton Buzzard triathlete and coach, now 65, (left, before the Marathon), was recently featured in Runner’s World for his remarkable late-career resurgence. E

arlier this year he ran a 1:29:35 at the Cambridge Half Marathon — his first sub-90-minute half in 16 years — winning his age category by nearly four minutes in a field of over 14,000. He ran his closing kilometre in 4:03. That’s not nostalgia. That’s form.

Over four decades, Mark has completed over 520 triathlons, 42 at Ironman distance, raced in 23 countries, and is one of only five Britons ever to complete a Triple Iron-distance triathlon. Of his 126 marathons, he has finished slower than four hours on just two occasions.

For the 2026 London Marathon, he is targeting sub-3:20 - his fastest in 25 years and 16 minutes quicker than his 2025 London result.

As a long-standing CurraNZ athlete, Mark is direct about the role our New Zealand blackcurrant extract plays: “Without doubt, CurraNZ made a big difference. Not only does it help me sustain a high level of intensity, but it also allows me not to slow down, which in the latter stages of a marathon is where all the time is lost.”

It’s exactly what the science shows. CurraNZ increases fat oxidation by up to 24% during prolonged exercise and augments pre-exercise muscle glycogen stores by ~39% - keeping fuel reserves intact when races are decided.

“Runners seek 1–3% improvements from super shoes,” he says. “CurraNZ delivers more than this.”

We couldn’t agree more. Read Mark’s full story over on Runner’s World.