Ex-Rugby Pro Runs 100 Ultras in 100 Days For Brain Injury Awareness
Mission IN-possible: David ‘Jacko’ Jackson Tackles 100 Ultramarathons in 100 Days for Brain Injury Awareness
Former professional rugby player David ‘Jacko’ Jackson is currently undertaking a monumental endurance challenge: running 100 ultramarathons in 100 consecutive days.
Jacko, who resides in North West Wales, is on track to set a new men’s world record for consecutive ultramarathons. The current record stands at 80 days, a milestone he is expected to shatter on August 17 in Bristol.
For the GB Ultra Runner community, the physical toll of a single 50km is well known, making Jacko's daily mileage an incredible feat of human endurance.
Challenge Overview
- The Challenge: 100 ultramarathons in 100 Days
- Daily Distance: 50km
- Dates: 29 May – 5 September 2026
- Fundraising Target: £1,000,000
- Charities Supported: Headway UK & Head for Change
The Journey So Far
Having started on May 29, Jacko is now more than two-thirds of the way through his staggering journey. To make the run as accessible as possible for supporters, the route covers 25 UK locations, with Jacko spending four days at each site running 5km and 10km loops.
By day 60, the statistics were already mind-boggling:
- He accumulated over 3,400km, which is the equivalent of running from Land’s End to John O’Groats twice over.
- Despite trying to stick to flat terrain, he conquered over 17,000 metres of elevation, equating to more than double the height of Mount Everest.
- More than 630 supporters have run alongside him, with participants ranging from eight to 80 years old.
- Notable runners who have joined him on the route include TV presenter Ben Shephard and fitness entrepreneur Ollie Marchon.
Behind the scenes, Jacko credits his wife, Catherine, as his main support crew, managing logistics, driving and cooking all his meals to keep him fuelled.
A Deeper Purpose
But for Jacko, this challenge is about much more than setting a Guinness World Record. In 2013, his rugby career with Nottingham R.F.C. abruptly ended due to a traumatic brain injury (TBI) and a seizure on the pitch during pre-season training. Following the injury, he faced severe fatigue, light sensitivity and cognitive issues for months.
It took him seven years post-injury to run his first-ever marathon. Now working as a breath coach with his company Pro Breathwork, he is dedicating his miles to raising £1 million for brain injury charities Headway UK and Head for Change.
“Mission IN-possible has not been easy and has been a huge stress on the body- but it is nothing compared to the brain injury that I recovered from back in 2013,” said Jacko. “The overall goal is to change lives; to help those affected by brain injury, to change the recovery process for someone in the future. The world record only matters if it helps change the awareness and understanding of brain injuries.”
According to Headway UK, someone is admitted to a UK hospital with a brain injury every 90 seconds, and the cognitive, emotional and behavioural effects can be devastating.
How You Can Support Jacko's Mission IN-possible
GB Ultra Runner community, if you want to support Jacko on his historic push to 100 days, here is how you can get involved:
- Donate: Contributions toward his £1 million goal can be made via his Givestar page.
- Track & Join: View his live GPS tracker at https://thebreathrunningcoach.com/mission-in-possible to see where he is running next.
- Follow the Journey: Keep up with daily updates on Instagram at @thebreathrunningcoach.
- Cheer Him On: He is expected to break the world record on August 17 at Sivo Wellness (Unit 7, The Stables, Leigh Court, Bristol, BS8 3RA).
