Jim Walmsley set a 50-mile world best on Saturday, May 4th, at HOKA ONE ONE’s Project Carbon X 100k. By running 80.4672 kilometers in 4 hours, 50 minutes, and 7 seconds (unofficially), Walmsley covered the distance 14 seconds faster than Bruce Fordyce’s unratified world-best split of 4:50:21 during the 1983 London-to-Brighton run, 44 seconds faster than Bruce Fordyce’s ratified world-best time of 4:50:51 from the 1984 AMJA 50 in Chicago, and 1 minute and 18 seconds faster than Barney Klecker’s American record of 4:51:25 set in 1980, also in Chicago. The IAAF, the sport’s international governing body, does not recognize the 50-mile distance for record purposes, and it’s for this reason that Walmsley’s newly established time is considered a world best, not a world record. Interestingly, both Klecker and Walmsley were 29 years old when they ran the above-mentioned times, while Fordyce was 28 when he set his ratified 50-mile world best.

Alongside Toni Reavis, Carrie Tollefson, and Juli Benson, I provided live commentary during Project Carbon X from a lead vehicle. As such, I had a front-row seat to witness a result that hadn’t been approached in nearly four decades. Yes, I am his teammate but here are my impressions from the front…

Tyler Andrews, lining up for his first race beyond the 50k distance, planned to run 5:38 per mile from the gun. Doing so for 62.1 miles would have netted him a 100k finish time of 5 hours and 50 minutes flat—nearly 20 minutes faster than the current world record of 6:09:14—although Andrews, like Walmsley, was targeting the 50-mile world best first (and perhaps exclusively). That intended pacing plan was likely revised by the start of the race, for Andrews seemed content to run about 5:45 per mile with Walmsley for the first three miles. But as the course moved from the roads of Folsom to the bike path along the American River – just shy of mile 3 – a small gap developed between Andrews and Walmsley on the small, undulating hills through the winding, tree-lined path. Ultimately, on the roughly 18-mile point-to-point stretch from Folsom to Sacramento, Andrews would average about 5:41 per mile to manufacture a lead of about 90 seconds over Walmsley. Meanwhile the two-time IAU 100k World Champion, Hideaki Yamauchi, feeling comfortable in the cool, early morning air that hovered around 50 degrees Fahrenheit for the first two or three hours of the race, kept the early miles honest and stayed within 20 seconds of Walmsley on the 30-kilometer stretch from Folsom to Sacramento. During these early miles, Andrews was accompanied by two pacers, Walmsley had three, and Yamauchi navigated the course with Tim Freriks by his side. All pacers were officially entered in the race and would start with their respective runners from the gun.

From my vantage point in the lead vehicle, it appeared that Walmsley was determined to run separately from both Andrews and Yamauchi. He briefly went to the front of the pack early in the race but as soon as Andrews pulled alongside him, tucked behind his pacer, Walmsley seemed to slightly withdraw his effort and disappear into the back of the small group. Likewise, as Andrews would drift left and right to take the course’s tangents, it seemed Walmsley would nearly do the opposite to remain disconnected. This general approach by Walmsley was confirmed when I later spoke with Walmsley’s pacer, Will Baldwin.

Baldwin said that when Jim took a quick bathroom break around mile 18, Yamauchi covered the gap and briefly moved ahead of Walmsley as Jim resumed his effort. (I did not see this since Andrews was over a minute ahead and I was in the lead vehicle in front of Andrews). Then, Baldwin said, Walmsley put in a surge to move ahead and disconnect from Yamauchi. In this way, Walmsley seemed intent to allow Andrews to cause his own demise, and to show Yamauchi that he ought not to try to keep up.

Andrews did indeed succumb to the early pace. After maintaining his early pace for the first of nine 4.71-mile loops, now almost 23 miles into the race and leading by nearly two minutes, Andrews began to slow. Walmsley told me before the race that if Andrews stuck to the intrepid splits he set out for himself, Walmsley would catch him about 70 kilometers (43.9 miles) into the race. It was thus surprising to see Walmsley move into the lead just before the halfway point in the race.

I yelled to Walmsley from the lead vehicle, voicing my surprise. He shrugged with a meager smirk that seemed to suggest, I couldn’t help myself. Walmsley had surged to low-5:30 per mile pace to quickly make up the gap on Andrews between miles 20 and 30. He seemed to gain strength as the miles stacked up. Not so for Andrews.

Andrews seemed to earn every 5:40 mile by paying back just a little too much each time. He slowly started to look less smooth. Although his pace was the same at the 22-mile mark as it had been at mile 3, the pace began to look faster because he appeared to be working harder. Eventually, his stride looked different and his face tightened up and he was running noticeably slower. He would eventually drop from the race soon after 50k. His was the gradually noticeable and then swift decline that I’ve both experienced and witnessed many, many times in ultrarunning. Not so for Walmsley.

From the moment the race started until the 60-kilometer mark, Walmsley looked entirely at ease. His bouncy stride looked effortless as he tore through mile after mile. His body language exuded the confidence and swagger that he’s displayed during course-record wins at the Western States 100, the Tarawera 100k, the Lake Sonoma 50 Mile, the JFK 50 Mile, and a dozen other races. He looked practically immortal. But after the 60k mark, even though the bouncy stride remained and the pace slackened only slightly, Walmsley finally looked decidedly mortal.

The first signs of fatigue were verbal. Just before 60k (37.3 miles), I asked Walmsley how he was feeling. He said, “Just okay”. The last time he responded that way to that question during a race, it did not go well. That was at the 2018 Ultra-Trail du Mont-Blanc, where he went out with the leaders and then wilted to a near standstill before dropping out.

Then, shortly after the 60k mark, when he was informed that he was almost three minutes up on the 50-mile world best, he simply grunted. But it didn’t sound like a grunt of approval, it sounded like a grunt of dismay or indifference—not what you’d expect if he was still feeling good.

As Walmsley slowed to around 6-minute per mile pace after 60k, his stride hardly looked the worse for it, but other signs of duress began to pour in. Around this time, he inquired about Andrews, wondering how far back he might be. The last time I heard him ask about his nearest competitors during a race, it was at the 2017 Western States 100 and he was on the verge of a hellacious bonk and eventual DNF. Then the guttural noises began.

The 4.71-mile loop that constituted the majority of the race required runners to pass under two overpasses with each circumnavigation. In each instance, the path would quickly descend below the bridge above and then rise rapidly to return to the previous elevation. Ascending one such section for perhaps the tenth or twelfth time of the day, and with more than 40 sub-6-minute miles behind him, the incline must have felt tortuous to Walmsley. He bellowed in agony, his head tilted down, and his gaze fixed on the incessant pavement below him. His arms swung swiftly to keep his bouncy stride fluent, and miraculously his stride did not break, and his pace hardly slowed. But at this point in the race, there was no hiding the fact that Jim Walmsley was suffering enormously. His barbaric cries confirmed what the race clock was telling the audience: Walmsley had been running at world-best pace for the better part of the morning, and now he was paying for it.

Watching the last 10 miles from the lead vehicle was much like watching a forest fire rip through a dry mountainside. I was fixated on the suffering in front of me, and I very much wanted to end that suffering on behalf of its unfortunate recipient, but I remained completely impotent, unable to do anything at all. It was difficult to watch yet I couldn’t stop watching. Walmsley seemed more tormented with each step. The concept of continuing the pace for another 100 meters, not to mention another handful of miles, seemed inhumane if indeed it was possible at all.

And yet he continued to clip off 6-minute miles. He continued to grunt…and curse…and spit. He continued to suffer immeasurably, and yet it hardly slowed him down. This is ultrarunning’s greatest challenge: to continue at a pace that was easy at first but is now excruciatingly painful. It’s easy to flinch in the face of that challenge. It’s easy to throw in the towel after the miles add up and the fatigue sets in. It’s easy to blame the conditions as unconducive, to say that the heat precluded a world-best time. It’s easy to slow to a walk when your body threatens to shut down. But to continue despite all this? That’s difficult. To continue on world-best pace despite all this? That’s almost unfathomable. But that’s what Jim Walmsley did.

The Watt Street bridge would be the final bridge before Walmsley made it to the 50-mile mark. He was just past 48 miles now and he had gone somewhere very deep and very dark to find the courage and determination to continue. He no longer looked like Jim Walmsley, the Western States 100 course-record holder, or Jim Walmsley, the three-time JFK 50 Mile winner. He looked as though he had lost some part of himself in the depths of his conscience, where he had been toiling at great cost for the past hour. Yet there existed a glimmer of that confident runner, just below the surface, gasping for air in deep breaths between the onslaught of discomfort that relentlessly thrashed his being like a storm-ravaged battleship.

Walmsley turned right and accelerated down into the start/finish line area for the seventh time of the day, now less than two miles from covering 50 miles on foot faster than anyone before. He needed to find one last gear now. He seemed to retreat into himself a final time in search of a few more drops of fuel in an otherwise empty tank that had brought him this far. I’m not sure there was anything left but he didn’t need it. Walmsley was running on an infinite fuel source in these late stages of the race. He was fueled by his dreams in those final, seemingly infinite minutes. His dream to break Klecker’s 50-mile American record. His dream to break Fordyce’s world-best time. His dream to prove, once and for all, that he is the world’s greatest ultra-distance runner.

When he crossed the 50-mile barrier at 4 hours, 50 minutes and 7 seconds elapsed, Walmsley did not celebrate. There wasn’t any energy left for that. He simply split the time on his watch and slowed to a jog. I’m not sure the record meant much to him at that moment. He said things like “My back hurts” and “I’m fucked” and “It might be a long afternoon”. He had another 12 miles to complete before his day was over. Five hours earlier, he had hoped to usurp the 100k World Record but by now he knew that dream would have to live on. He would simply need to finish this race. He did so in 6:55:24. (Writer’s note: Other media outlets have listed Walmsley’s time as 7:05:24. That’s incorrect. There was a relay as part of Carbon Project X and that race started at 5:50 am, 10 minutes before the individual 100k race. The clock at the finish line reflected the 5:50 am start time, not the individual 100k start time.) Yamauchi would win the race in 6:19:54.

The significance of Walmsley’s achievement can’t be overstated. Klecker’s American record for 50 miles was established 39 years ago and was the longest standing record of all USATF American open road records. Fordyce’s world best was set some 35 years ago, and the 9-time Comrades Marathon champion’s time has long been touted as one of ultrarunning’s stoutest performances. In some circles, the decades-old record was revered as nearly unbreakable. The sport of ultrarunning took a significant step forward with Walmsley’s result.

As always, Walmsley’s performance won’t put an end to many debates. Analysts and onlookers and basically anyone with access to the internet will debate the significance of Walmsley’s run. They’ll debate whether the 50-mile world best even matters (it’s not recognized by the IAAF, after all). They’ll argue that some five dozen Africans could run much faster if they cared to try. They’ll say a whole lot of things.

But there’s one thing that’s indisputable: Jim Walmsley ran 4:50:07 for 50 miles. That is now a world best.