Race Rewind: The Tactics That Led Casper Stornes to an IRONMAN World Title
Casper Stornes is the male 2025 IRONMAN World Champion, prevailing out of a pack of five men that left T2 all together to start the marathon on Sunday. Marten Van Riel, Sam Laidlow, Gustav Iden, Kristian Blummenfelt, and Stornes ran together through the opening miles of the run, with Nick Thompson less than a minute behind. It was arguably one of the greatest run battles we’ve ever seen at an IRONMAN World Championship.
One-by-one, athletes started to fall away. The first to fall off the hot pace was Van Riel, who had battled injury during the summer months that significantly impacted his run training. Laidlow was next to start paying the toll, with the gap opening up over the second lap. And it looked like Stornes would be next; Iden surged, with Blummenfelt coming forward with him, and Stornes suddenly was 35 seconds behind the lead with 15.5 miles to run.
After the race, Stornes told us this was by design. “I needed to be smart if I wanted to beat them,” he said. “Gustav put on quite a heavy pace and I was like, ‘Is he going for a 2:25 [marathon]?’ “I felt actually quite good. But it’s easy to feel good at the start of a marathon also, so I didn’t take anything for granted that I would feel like that the whole way.”
Surging forward, Stornes caught Blummenfelt and Iden to begin the third run lap, and started putting time into them. And he wouldn’t be caught. The 2:29:25 marathon brought Stornes the world title, and with Iden and Blummenfelt sweeping the podium for Norway, it also made it the first time that all three podium finishers had an IRONMAN world title to their name.
Stornes’ masterclass in run pacing was the critical component to his victory on Sunday. Not many athletes would have the discipline to allow Iden and Blummenfelt to run up the road with that little time left on course. Yet Stornes trusted the plan, and executed it to perfection. But it was just one piece of the overall puzzle that fell into place. There were at least two other critical components to his victory.
Swimming in the Front Pack
By most accounts, Stornes is not one of the elite swimmers in long-distance triathlon. To be clear, he’s not someone who is giving up a large deficit in the water. But Stornes is typically in that second-tier swim level; he’s around Blummenfelt, which means he’s going to be giving up somewhere between 30 and 60 seconds on the leaders.
In Nice, though, Stornes held onto the front pack of the swim. He was the back of the leading swim pack, led by Andrea Salvisberg (pictured above) and which featured athletes like Jamie Riddle, Van Riel, the typically dangerous Antonio Benito López, and Jonas Schomburg. He was 40 seconds clear of some typically front swim-bikers like Blummenfelt, Magnus Ditlev, and Matthew Marquardt. And he was two minutes up on Iden.
It meant that, with firepower on the bike behind him, instead of in front of him, Stornes could tactically ensure he waited for the right moment in the ride to start executing. That came roughly a quarter of the way into the bike.
Laidlow’s Charge to the Front of the Chase
Sam Laidlow had, by his standard, a terrible swim. He, like Iden, was in the third group of swimmers, two minutes down to the leaders. It’s a far cry from how he typically executes a race; like Lucy Charles-Barclay, he’s an athlete that gets to the front early and tries to stay there all day. Sometimes it works brilliantly, like it did in Kona 2022 and when he became IRONMAN World Champion here in 2023. And sometimes, it ends disastrously, as he came unglued on the run last year in Kona.
As Laidlow told us after the race, he had cramps in both hip flexors that he found debilitating, nearly pulling the plug on the event before it had really gotten started. “I had to stop and stretch it out,” he said. “It was a long swim. I couldn’t wait to get out of the water, to be honest.” (Editor’s Note: you know you have incredible swim talent when you have to stop to stretch and you still clock a 47 minute swim.)
Laidlow originally had made plans with Van Riel and Riddle to swim hard, and then make an elite level bike group up front. Tactics like this aren’t uncommon — Chris McCormack famously goaded some of the then-elite bikers to try and ride away from Craig Alexander at the 2010 IRONMAN World Championship, and then won the race because of it. Of course, Laidlow missed that group, whereas Van Riel and Riddle forged onward with Schomburg to stay away.
It meant when Laidlow caught up, there was an opportunity to hang with him. Stornes, Blummenfelt, and Iden took advantage of it, forming an elite chase group. Also along for the ride was Ditlev and Thompson. They dropped Rudy Von Berg in the process, meaning the Von Berg would not be able to use his familiarity with the course and the descent as an advantage in the same way he did in 2023.
That group mostly stayed together until the halfway mark, when Laidlow and Blummenfelt put in a concerted effort to close down the gap to the leaders. Thompson, Iden, and Stornes stayed back, but kept the gap to under two minutes. It took forever for Laidlow and Blummenfelt to bridge to the front, only finally making contact with Van Riel after thirty miles of chasing. By the time the race was back in Nice, proper, the six leading men were spread across 35 seconds — setting up for the run battle to come.
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I’d argue this was an easier decision than this article might imply. Stornes is quoted earlier as saying he thought they were going for a 2:25 and made the call he wasn’t able to do that. The tactic in this case was simply that he knew he’d blow up if he went with them.
Counterpoint: you have two world champions pulling away from you with 15 miles to run and you’ve seen them set run course records all over the world.
Think there’s a lot of athletes that may have rolled the dice on going with those two guys.
I wonder if you could have made more of his bike tactics, similar to Iden, of rarely putting his nose in the wind, accepting that if athletes went away, as Laidlow and Blummenfelt did, then fine, they are burning matches and we’ll catch them later.
I have not rechecked but think that Thompson and Iden were the drivers to catch the leading (now) trio with MvR caught by SL/KB on the descent and flat 12km back to Nice. Did Stornes do any work? Well done him.
If KB had let SL go, which is what he should have had the confidence to do, and rode as a Thompson plus Norges quartet, that last third of the marathon might have been different.
On the run, Stornes had really equal 10km splits (35:20 plus or minus 10 seconds) but maybe this disguises the rise in pace which dropped KB and I need more granularity. Stornes must have wasted 20 seconds in T2 which meant he had to work to catch up - why? And he had to do that before the turn to have draft in the headwind return leg: he just made that catch at 5km.
Same with Iden and Blummenfelt running at too fast a pace, downwind. Stornes was measured and confidently prepared to let the gap go, but not too far. I’d like to know how each of these athletes judged their two peers in terms of risk level: you’d think they’d know who would be best when the chips were down after halfway. Did Iden and Blummenfelt race one another too much for two laps?
Loved the echelon and thought: put them in the gutter, and seconds later MvR did just that.
Thousands of spectators had a roadside seat watching these battles. What a pity they will never get the chance again to see the pack running, gaps, splits, recoveries, breaks ever again. But, hey, the Energy Lab is iconic and athletes, pro and amateur, appreciate the solitude and ‘suffering’ away from the pesky noisy plebeians. Sure they do.
It is almost never that this many people get off the bike together and anyone who is ‘dropped’ comes back and does a ‘re pass’.
In an interview that Bob Babbit did with Mark Allen , Mark mentioned that coming from a swim background if someone pulls away they are gone for good. When he got into triathlon he thought that is how it just works but he did some races where he got dropped and came back and realized this sport is different.
But largely in Ironman running it is a game of attrition. Either someone is out front solo and gets caught, tries to keep up and gets dropped after a hundred meters or a couple of athletes start together and when one gets dropped the game is over.
I can’t think of an Ironman where a large group came together off the bike and things did not instantly explode and rather a pack ran together deep into a race eventually going to a game of attrition…
The race that comes to mind was Ironman Melbourne 2012, when To Crowie, Cam Brown Freddie Van Lierde, Eneko Llanos and came off the bike together. If I recall correctly the pack went through 21km in around 1:19 which at that time was unheard of. Crowie was the only one who kept the pace. I think Cam Brown fell off to a 2:41 and Van Lierde did 2:42. Crowie did a 2:38. That was all in the pre supershoe times but there was no dropping back to tune into ones pace and coming back as no one had confidence they could reel Crowie back in and at that point Crowie had never run a sub 2:40 Ironman just like Blu and Iden have never run sub 2:25. The other guys tried to keep up and lost via attrition of a hot pace
Had the other guys backed off to go at their pace in Melbourne saying to themselves ‘Crowie never runs sub 2:40 let him go and blow up’ they would have lost the gamble.
But Stornes either won the gamble that the guys can’t run 2:25 or it was a personal reality check that running 1:12 half marathon pace would result in an implosion to 15th place and he took the safer route not out of intelligence of knowing his mates would blow but out of self preservation fear (not a bad thing )
100% agree with this. Although, he did say in the pre-race press conference that the person he was most scared of was Sam. Easy to say and much harder to do. Watch the athlete you view as the biggest threat ride away and have the confidence that you will catch him later. He’s had such a great season, he should have trusted in himself. But Im sure its a very hard thing to do.
But Blummenfelt KNEW that he could surely take 6 minutes of Laidlow (PB difference). As you say, he should have trusted his plan. On ProTriNews (I think) the suggestion was made that he had a Plan A and a Plan B, but failed to stick to Plan B and confused himself by partial reversion to Plan A.
I can envisage Laidlow well up the road if only he’d swum ‘normally’ (with the Whatsapp group ‘Attackers’). Blummenfelt would’ve had to ride, as opposed to his normal wheel sucking (IMWC not any old IM). Who else would’ve helped pull (to keep the gap down)? Iden probably. Noone else. Ditlev, except he never made it up there, and was sick/ill. (Gutted it out for two run laps before DNFing.)
Watch the athlete you view as the biggest threat run away and have the confidence that (he/they) are overdoing it and you will catch him later. Stornes trusted himself; once on the bike and once (or twice) on the run.
Everyone here is throwing out this or that theory on what some should have done or not done, but who do you think was even thinking about Stornes during the race as a threat? How many here had him winning, or even in the top 3? Guys were keying off of racers who they knew were going to be there, or should have been. It is a guessing game and you guess based on past experience. Believe me, Stornes was well down the list of guys anyone was going to change their tactic for mid race…
My question on tactics is why do guys continue to go to the front of the run and set pace, when they know they are not the strongest runners? I saw Martin, Sam, and Blu all playing Quienes es max macho up there, when they should have been hiding in the back and just hoping to hand as long as possible. Poking the bear, sticking a stick in the hornets nest, what comes of that strategy, you just get dropped sooner…Now for Iden I get it, he was feeling good, like his old self, and he has run everyone off his back before many times. It sure looked like all the others were all on the rivet, so hide until you know you can take the lead, like Casper maybe???
His splits were pretty consistent.
This video is a great watch too, in order to answer some of the tactical questions going through the Norwegians’ minds during the run as well as the race nuances during the bike.
Iden feared Kristian’s final 10km on the run so much that he got lured into running too fast. As noted above, Stornes just did his own thing, sticking to his 3;30km pacing plan.
“Believe me”, Blummenfelt and Iden will surely have “thought” Stornes was a threat, as soon as he managed to catch them at the first turn. And that would have been a very informed “guess”.
Who was “changing their tactics for, mid race”? Mid race when Laidlow pushed, do you think Blummenfelt thought Laidlow was the main threat? If so that was irrational: hubris, perhaps. And not just with 20-20 hindsight. He had to know how well Iden and Stornes were running.
Yep. Stornes let them go by as much as 35 seconds at circa 10 miles (gutsy but sticking to pace). But with Iden and Blummenfelt trying to get the other to take some wind on Lap 2, their pace dropped and, within 8 minutes, Stornes caught them before end Lap 2 and all three together downwind for a mile.
A mile later Stornes on the front, downwind on Lap 3, Iden dropped at about 15 miles and then Blummenfelt ‘let go’ at 17 miles.
Really very little pace change from Stornes (see graph).
Cramps in the hip flexors during the swim. Hope I never feel that, that is a really key connection in the body!
Ya it seems very weird for such a good swimmer to get cramps at the start of the swim.