This was the hardest thing I’ve ever done. Running 100 miles non-stop, pretending I can cycle and swim, Marathon des Sables.. none of them as tough as running on a treadmill against the clock to beat a world record.

Having already run 50 miles on a treadmill to take part in research at Kingston University - without sounding too arrogant - I found it quite easy. It took 8 hours and I hopped off feeling quite fresh. When a friend pointed out that if I had kept going I would have broken the world record. Together with the Sports Science department at Kingston University we hatched a plan to give it a go.

Fast forward 6 months and with the green light and a huge list of rules from Guinness World Records the date was set. Dr Hannah Moir and PhD researcher Chris Howe got everything together. We needed two independent witnesses and two time keepers every four hours to satisfy GWR. Some very cheery students had volunteered. The first on the rota had got up at 4am to get there! Incredible! I would have a team of friends running next to me at various points to help spur me on. The existing official record sat at 60.26 miles and there was an unofficial record of 66.79 miles. I had picked up some niggly injuries over Xmas and was not fully fit, but the great thing about endurance running is that it stays in your legs. The plan was to get past 70 miles - I felt comfortable with my goal.

We decided to announce it during the week before the event and that’s when things started to escalate. By Thursday hundreds of messages were coming in wishing me luck. I was beginning to lose my nerve, it suddenly seemed like a big deal. After all, it was me running on a treadmill, for a long time; I needed to relax. How on earth top athletes deal with the pressure of the race of their life in something like the Olympics I will never know.

So 12 hours on a treadmill. 12 hours of exactly the same thing. Here are the good and the bad things that happened:

GOOD

THE SUPPORT TEAM – attentive, kind, encouraging, positive. Kingston University Team really looked after everything. The organisation was so smooth. I didn’t have to worry about anything. It was sorted.

FELLOW TREADMILL RUNNERS – A fantastic team of volunteers who ran alongside me for hours. They did it in shifts. I began to lose all powers of conversation by about half way, but so grateful to my fellow treadmill runners for helping me through.

THE OUTSIDE SUPPORT – social media was plastered in front of me for 12 hours. Twitter, YouTube, Using the hashtag #susieWRrun, Instagram and FB messages were being fed to me non-stop. The messages (some from as far away as USA, India and Singapore!) the cheers, the funny GIFs, the sheer BELIEF everyone had in me - like visual EPO spurring me on. When I became too dizzy to focus on the screen the team read them out to me. People came into to cheer and watch too. It was heartwarming.

PAULA RADCLIFFE – Paula Radcliffe tweeted me. I mean, PAULA RADCLIFFE!

BAD

THE BUCKET – Nearest loo is a few minutes walk away. The quickest most expedient option was a bucket in a cupboard. Oh yes.

THE SAME SPEED - my pace only varied by just 45 seconds a mile for the whole 12 hours. Running outside you have natural fluctuations. You might run an overall 9 minute mile, but every step won’t be at the same pace. That didn't happen on the treadmill. I was locked in to the same speed for hours. It was relentless

THE WALL – it was around 2m in front of me and after about 6 hours I was feeling dizzy as the view was flat. My depth of field remain unchanged. Like motion sickness on a boat my eyes went squiffy. It was making me feel quite unwell by 8 hours.

THE BUCKET – it was far too low to the ground. I needed help onto/off it towards the end. Sexy.

MY OWN MIND – The most important tool in endurance running. It turned against me: Hmm, my ankle hurts a bit. Oh now my shin. Is that a twinge in my knee? OW. Achillies hurts. This is not good. This will get worse. Repeat these thoughts for 12 hours. Whilst running facing a wall.

THE BUCKET – Stomach issues hit me from about 30 miles. It was not fun. Energy was low and the bucket visits were much less fun.

THE FEAR – Once again my own mind made things harder. Would I cock this up? I mean, I knew I could do it.. but anything could have gone wrong. If I fell over that would have been it as the treadmill readings would have been wrong. I worried about falling over more as I got tired. I worried a lot about missing the record. I was not feeling on top form and exposed. I was on schedule for 70 miles in 11hrs15min for quite a long time. Over 3000 people had watched on line, everyone was rooting for me. The pressure got to me and things started to drift perilously close to failure. It was mentally so very tough.

All my loo stops amounted to 11 minutes so I spent 11hrs 49 minutes running at almost exactly the same speed. It became excruciating. Added to the wall staring it was so hard. So so hard. You’ll notice the BAD list is longer than the GOOD list.

However the BAD list is less significant. Those few things on the GOOD list outweighed the BAD list by far. I’ll admit THE FEAR really got to me, but what got me more were the wonderful, funny encouraging messages. The sheer faith people had. The people coming into the lab to cheer, bringing their kids in to write encouraging posters which were stuck on THE WALL (thank you kids!) The YouTube support was almost overwhelming. Kind words. Funny words. Uplifting messages. My dear friends who ran next to me. Hannah and Chris who had worked so very hard all day, the KU students telling me how well I was doing, even though I must have looked awful. My devoted wonderful husband, by my side all the time, whilst simultaneously being everywhere and sorting everything out.

The truth is I was disappointed to not make 70. But the bigger truth is, it still happened. A world record, an actual world record. It was a huge team effort. Everybody played their part in it. I just did the running bit.

Everyone else made it happen.

Thank you all. Xx

THANK YOU’S:

SUPPORT TEAM Kingston University – Scientists Dr Hannah Moir & Chris Howe. Witnessess: Sally Tesfu, Luke Morton-Holtham, Josiah Obeng, Latisha Forbes, Marthe Solberg, Josh Carter, Jack Brotchie, Tom Payne, Simone Benedetti, Christof Leicht, Anna Kosciuk, Carla Molinaro & the media team. Huge thank you.

RUNNERS: James Warren, Stuart Williamson, Tim Jones, Neil Ambrose, Charlotte Hanson, Sophie Raworth, Cyra Parks, Rob Gilchrist, Shaun Marsden, Jane Mezzullo, Alan Chan, Tom Garrod. You lovely wonderful people. Nearly giving me a heart attack when some of you tripped on your treadmill.

OTHER: Farnham Runners, Duncan Hards for fixing my achillies in the nick of time. Dassi Bikes.

KIT SPONSORS: WAA Ultra, Injinji, Ultimate Direction. Beta Climbing Designs. Thank you to Hoke One One also.

On top of all of the above I want to say a huge thank you to all who sent me a message of any sort. Extra special thank you to Hannah and Chris for the huge amount of work on the day, and just when you thought it was over, coming on a 500 mile round trip straight after to the BBC in Manchester. Charlotte Hanson for literally lending me the clothes she was wearing to go to Manchester, being a chauffeur and keeping my secrets. Lastly but no means least Shaun Marsden. The most selfless wonderful man. Sorry about the whole ‘bucket’ thing xx

Photo credits: Shaun Marsden, Romilly Lockyer, Kingston University.