The tough 24hr ultra format - tips from the woman who set the world record.

This edition of the Performance Lab comes to us courtesy of 24hr World record Holder, Sarah Webster. Sarah ran 278km to take the women's crown in France in Oct 2025. A veterinarian by trade, Sarah is also an elite ultra runner having proved herself on the track but also the trails, setting a course record at South Downs Way this year.  

Like any ultra, running for 24hours is as much mental and physical.

My first 24 hours was round the track.  No hills, no mud, nowhere to hide and the only change in muscle movement is changing direction every 4 hours.

I made the big step from 100k in 7 hours to 24hours.  Run as far as you can in the time. 

Setting a target: good and bad. This is good as it gives you something to aim for, bad as if you reach the target before the time is up, your mind wants to stop and then your body starts to give up. I broke the world record with an hour to go.  The only thing keeping me going was the race would be lost if I stopped as the other 2 girls were chasing me and, in the end, they broke the record as well.

Training: Keep one speed session per week but the rest of your sessions are slow.  Strength and conditioning are vital to keep injury free and to give your body the strength it needs to keep going.  My first 24 hours I didn’t run double days – life got in the way.  2^nd time I fell and dislocated my shoulder 7 weeks before the race (do not try this at home).  What seemed like a disaster actually worked.  I was back running within a few days – with a sling, my running was unstable and slow.  I also couldn’t drive.  So, I had to run to work, gym, physio etc.  My mileage jumped, my speed was non-existent but very race specific training.

You do need to do long runs as well: to practice the mental game some of them need to be round a track or a short lap (2km or less if possible). And the goal is time rather than miles.

Practice fuelling in training.

Have a race plan and a crew: having a good crew can increase your performance by 10% apparently.  My first 24hours my 16-year-old daughter crewed the entire thing on her own.  She did incredibly well, she stayed positive the whole race even when things were going wrong for me.  You will have highs and lows in any ultra, the good thing is you have time to recover and come back up to pace during the race. Just take things easy for a few laps/hours!

I had the British team crewing for me at the world champs which was amazing.  They thought what else I might need especially when I wasn’t following the plan anymore.

Pace: this is a hard one.  You will slow down.  You need toilet breaks (very good excuse to sit down but not long!). If you have a target, then you can work out pace.  But remember your stoppage time.  First time I had a plan to walk a bit every hour to have a break: didn’t work as I was too fresh in the beginning and then my back went and I ended up walking for 4 hours.  2^nd time: the plan was not to walk at all. I stopped every 4-5 hours and did a few assisted squats which become more frequent as I became more tired, but it helped ease the pain in my legs.

My first 24hours: the aim was to still be moving at the end of 24hours unless I was unconscious or the medics stopped me.  I walked for 4 hours and then began to run again for the last 90minutes (yes, it hurt). The 2^nd time I realised that if I didn’t spend 4 hours walking then I had a chance of breaking the word record.  I had to ignore the fast pace and just run my own race.  It worked!