Kilian Jornet posted on social media an explanation for why he dropped out of his 24-hour running record attempt after just 10 hours of running loops. “It didn’t go as I thought. I was expecting to enter that pain zone to push my body but I broke in another way,” he said on Instagram. Jornet, 33, is best known for his mountain running, but he swapped the mountains for flats in an attempt to set the record for the furthest distances covered in 24 hours. He did continuous loops around a track in Norway, hoping to eclipse 303.506km, set by Yiannis Kouros in 1997. “The race started well, went all normal, with its small ups and downs, some small but normal pains, but as planned until just after 10 hour when I suddenly felt two consecutive sharp oppression pain in my chest,” Jornet wrote. View this post on Instagram A post shared by Kilian Jornet (@kilianjornet) “I got very dizzy and get medical attention, thanks to the doctor who was in the race (sorry I forget your name) for your help the ambulance took me to the hospital where I’ve been doing tests and in observation this night. All seems OK now! No big problems but will be good to do some further tests.” Jornet is considered the best mountain runner of all time. He has won every major trail and ultra mountain race, including three victories at the Ultra Trail du Mont Blanc, four Hardrock titles including one when he set the race record and another with a dislocated shoulder, and six 31km Sierre Zinal titles setting the record on his latest win in 2019. He also won the Western States in 2011. He holds seven 42km Zegama-Aizkorri wins in Spain. A MESSAGE FROM KILIAN "Racing is unpredictable, sometimes even with great preparation things happen, but races and mountains will still be there...And the 24h are still on the list ;)" - @kilianj pic.twitter.com/cRlk6S2ryK — Salomon (@SalomonSports) November 28, 2020 But Greek Kouros is Jornet’s equal in the world of flat ultra running. Along with the 24-hour record, he also holds the 48-hour record on a track (473km) set in 1996, and the six-day record (1,036km) set in 2005. He won the 246km Spartathlon four times – all under 22 hours, a feat no other athlete has achieved since it started in 1983. Switching from mountains for flat running was ironically destined to be an uphill struggle for Jornet. Jornet wrote: “Now I will take a break, try to rest a bit. Racing is unpredictable, sometimes even with great preparation things happen, but races and mountains will still be there … and the 24 hour are still on the list.”