Best friends design and complete their own Ironman challenge across London

Alistair Marks and IDF veteran Dor Zakai raised £30,000 for Yad Sarah


With the terror attacks in Israel and war in Gaza meaning that the half Ironman was cancelled in Israel, two UK-based friends decided to take on the challenge in north-west London to raise much-needed funds for Israelis.

UK Friends of Yad Sarah trustee Alistair Marks and IDF veteran Dor Zakai completed the gruelling half Ironman challenge on Friday, raising a remarkable £30,000 in support of the Yad Sarah emergency appeal.

The challenge, known as Ironman 70.3, consisted of swimming 1.2 miles, cycling 56 miles and running a half marathon covering 13.1 miles.

Alistair and Dor, who met at the gym in Golders Green, trained for up to 12 hours a week for close to four months to take part in the challenge, which was originally planned to take place close to Lake Tiberius in northern Israel. But following the outbreak of the Israel-Hamas war, it was called off just one month before it was due was to take place.

Faced with the cancellation of the official event, Alistair was determined to complete it and began painstakingly measuring out a route around London instead, which included six laps around Regents Park for the final running leg.

The pair, luckily benefiting from fair weather, conquered the gruelling trial in just under six and a half hours, a particularly impressive time considering they battled Friday rush hour traffic on their bikes.

Alistair said: “It was a challenge logistically, and we didn’t have the fanfare of the official event, with only my dad to cheer us on, but it was a great experience and a real sense of achievement.”

He thought about giving up a couple of times, “I would then remember why we were doing this, and however hard it was, it was nowhere near as hard as what people in Israel have been and are still going through.”

Later that day, after completing the triathlon, Alistair spoke about the experience at his synagogue, Finchley United. He said he would have been “extremely happy” to raise £10,000 through taking on the challenge but was “overwhelmed” to have tripled that target.

He said: “It helped to have Dor along for the ride, who, despite worrying about his friends and family in Israel, was very motivational and didn’t stop for anything. He went over his ankle 2km into the run but kept going.”

Dor, who finds it “tough” to be separated from his country, said: “We knew at every moment through training and the challenge whom we were doing this for, and that fuelled us.

It may just be a drop in the ocean, but we wanted to help in any way possible. We couldn’t have completed it without Alistair’s dad, the third member of our crew, who watched the bikes and refilled our water.”

With over 120 branches in Israel, Yad Sarah is Israel’s largest volunteering charity and non-governmental social and healthcare service provider. You can support the appeal at

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