World Record Bid - 200 Marathons in 100 Days - Breathing Coach Takes on “IN-possible” Challenge

At a glance

David 'Jacko' Jackson, a former rugby player whose career ended due to a head injury, plans to run 200 marathons in 100 days starting May 2026 to raise £1 million for brain injury charities Headway UK and Head for Change. This challenge aims to break the world record for consecutive ultramarathons and highlight the importance of recovery support for brain injury sufferers. Jackson's effort will take place across 25 UK locations, inviting public participation to foster community support and awareness.

A professional rugby player whose career was destroyed by a head injury is running 2 marathons a day for 100 days, for 2 brain injury charities - breaking the world record for ultramarathons in the process and aiming to raise £1million for the two brain injury charities.

“Everyone thinks my new challenge is impossible.”

From late May 2026, David ‘Jacko’ Jackson is to attempt a world-record 200 marathons in 100 days. The former rugby union player hopes to raise £1 million for brain-injury charities Headway UK and Head for Change and will be running in various locations across the UK.

The gruelling challenge, entitled “Mission IN-possible: 200 Marathons in 100 Days”, will begin on May 29, 2026, the day after Jackson’s 44th birthday, and he is aiming to complete it on September 5, 2026. Jackson, after covering more than 8,450 kilometres - the equivalent of running from London to Los Angeles - is expected to break the current men’s world record for consecutive ultramarathons, a feat never achieved on this scale. The current record is held by fellow Briton Sam King with 80 consecutive ultramarathons in 80 days.

In 2013, David’s promising professional rugby career was abruptly ended by a traumatic seizure during training for championship side Nottingham Rugby for whom he had been a prolific try-scorer. He was told by medical experts that a repeat event could be fatal. He admits that after such a serious brain injury the road to recovery was uncertain and, at times, simply returning to normal life felt impossible.

“Everyone thinks my new challenge is impossible,” said Jackson. “But I believe in IN-possible. That belief runs deep - and it’s something my recovery taught me.” Seven years after his brain injury Jackson ran his first marathon. Now he is attempting to run two marathons daily for 100 days.

“My injury took something from me - but recovery taught me how to turn something bad into something good.” A major part of Jackson’s recovery involved running and breathwork, tools that helped him rebuild both body and mind. But he is acutely aware that not everyone affected by brain injury has the same access he had to recovery, rehabilitation and long-term support.

He said:

“I’ve experienced first-hand what recovery can look like - and I’ve also seen what happens when people don’t get that chance. That’s why this challenge is for Headway UK and Head for Change - and for the people whose lives are changed forever by brain injury.”

The “Mission IN-possible” routes have been designed to bring people together across the UK. Jackson will run at 25 locations, spending four days at each, and completing the daily distance through 5km and 10km loops. Anyone - runners, walkers, first-timers or experienced athletes - is welcome to join him.

“This isn’t just about supporting from the side lines,” Jackson added. “It’s about being involved. Running your own little ‘IN-possible’, whether it’s your first 5km or something much bigger, is about believing in yourself again and drawing on the support of each other as I’ve experienced strength is multiplied when shared.”