London calling: Alex Yee’s London Marathon training

When Alex Yee took the finish line tape cross-armed and fixed a steely gaze down the camera lens, it caused a bit of a stir. Just as at the Olympics a month earlier, Yee had outsprinted Hayden Wilde. This time to win a Supertri event in Boston, but unlike in Paris where they had embraced on the blue carpet, now there seemed to be an edge.

Was Yee’s longtime friendship with the Kiwi starting to turn a bit fractious? Not really. In the clamour for a post-race news line, too much was made of Yee’s celebration, but in contrast to the broad grin that marks him out as one of the most easy-mannered triathletes in the world, it was a visceral reminder of his determination.

For all of Yee’s natural talent and flowing running form, he hasn’t become the most decorated Olympic triathlete in history (two golds, one silver, one bronze… and counting) without the attitude to win.

Both the smile and the work ethic will be present when he steps up to his next big challenge this spring as Yee takes a departure from the competitive rigours of swim, bike and run to hit the streets with 50,000 plus other nervous entrants in this year’s TCS London Marathon.

To manage expectations, this isn’t about winning the race. It’s an exciting opportunity to see how triathlon’s best shapes up against the world’s best, and while Yee has said somewhere between 2:07 and 2:10 might be attainable, he’s well aware that even such an impressive debut (sub 2:08 would put him in the all-time GB top five) is only likely to put him among the ‘also-rans’ coming down the Mall.

• Why Alex Yee’s plan to tackle this year’s London Marathon is so intriguing

Short-course success

If Yee needed any further reminders of that, then a 28:07 clocking over 10km on the roads of Valencia on the second Sunday in January, placed him 29th. He’s stepping into a different game here in the competitive running world, with new threats emerging, chiefly from east Africa, almost every race.

But Yee, who grew up competing for Kent Athletic Club and has proven himself to be the best short course runner in triathlon, also wants to show his worth while he has chance. The furthest he has run competitively is 10km and it is more than six years since he took the GB 10km title on the track in 27:51 at the joyously curated Night of the 10,000m PBs in London.

“I don’t really feel I have moved my running on over the last few years and 2025 is the year to do it,” Yee says, explaining his reasoning. “Having a run focus opened up the chance of running a marathon, and London is a special place for me. It’s a place that gave me so much as a child. London Marathon Day, especially, was such a big part of my life growing up, I have great memories of racing the mini-marathon for Lewisham and seeing the city come alive around the race. So it was a no-brainer.”

That’s where the smile will be even broader. Even as the race gets tough into the closing stages, the crowds lining the streets like no other marathon will save a special cheer for their local favourite.

The organisers are also relishing the first time an Olympic triathlon champion has started amongst the elite field, and distance running legend and four-time London winner, Eliud Kipchoge has stated he’d be happy to give Yee some advice.

Yee’s spectacular triumph on the Pont Alexandre III in Paris was also voted Team GB’s Moment Of The Games and led to a worthy nomination for BBC Sports Personality of the Year (SPOTY). “It was a fantastic year and to finish it with SPOTY was a surreal experience,” he adds “It was an honour to have been shortlisted alongside some incredible names.”

Increasing the distance

Now it’s all about 26.2 miles, and a choice that makes sense. It’s four years until the Los Angeles Olympics and while that will fly by, racing triathlon around the globe, either on the World Triathlon Championship Series – where he became the first British men’s world champion for 12 years in October – autumn’s Supertri series, or even potentially the T100 World Tour, takes a toll. Now is a limited window to try something different in the knowledge that there’ll be no shortage of swim, bike and run offers when he returns.

Yee and his support team in Loughborough headed up by coach Adam Elliott are under no illusions at the size of the task, and while there was an element of tongue-in-cheek fun, Yee’s Strava post on January 17 titled ‘Yeah.. marathon is gonna be hard’ suggested the training is bringing that home.

In that session Yee ran 29km in 1hr 52min at an average pace of 3:52/km and quickened to 3min/km at peak – almost the exact pace he’ll need to run to hit the upper end of his target. It’s mind bogglingly fast to mortals, but while Yee is no ordinary athlete, some things about marathon training don’t differ: it’s about patience and managing risk.

“My training structure won’t actually change all that much,” he explains. “I’m still committed to developing as a triathlete over the longer term, so swimming and cycling will be part of my regular training throughout the week. However, there will be an obvious need to increase my run volume and do longer marathon-specific sessions.”

Training as a triathlete is another intriguing angle to this experiment. Such is the level at the top of triathlon, that Elliott believes cutting swimming and cycling out of the programme completely for four months could leave Yee having to play too much catch-up when he returns.

Particularly, when it comes to swimming, where, as the coach explains, he’s dedicated himself to the improvements to make the front pack. The other benefit of cross-training is it reduces the risk of injury, particularly to the lower leg, if Yee tops out at around 130km per week rather than closer to 200km like most elite marathon training programmes.

Load is something that all athletes need to manage. Various studies have been undertaken to try and ascertain the extent of injuries in first-time marathon runners, and while the figures differ, data from a study on the New York City Marathon suggested one in ten runners (9.5%) picked up an injury serious enough to stop them starting or completing the race, and an additional 49.2% had minor injuries that interfere with training or performance.

Monitoring fitness

“I don’t have any concerns around the marathon or the training, it’s actually very exciting,” Yee says. “And like I said, it’s all part of a bigger plan of being a better triathlete.” One benefit Yee has over amateur athletes is that he has a team monitoring his workload, alongside his own perception, which might be the most important factor. Coach Elliott will analyse the results of each session to see how he’s absorbing training.

For example, is Yee’s heart-rate too high for a particular pace? Or how are his lactate thresholds changing? Yee also has a partnership with COROS, whose Pace Pro multisport watch helps him monitor both his fitness and his freshness as well as everything else you’d expect from a sports watch.

“The first thing has always been how light in weight it is, I’m still surprised today, and often forget I’m wearing the thing 24/7,” he continues.

“Battery life and the COROS Training Hub are other standout features for me, being able to analyse the raw data after I train or perform in a race is particularly important. To see what’s been done has been really beneficial for my progress.”

Yee can also pair it with the COROS Heart Rate Monitor and COROS Dura power meter. “As I mentioned, swimming and cycling will still form a large part of my training, and the COROS DURA is great when out on the bike and looking at power,” he explains. “When it comes to running though, I’ll focus on the usual three elements; pace, distance and heart-rate. I’ll make sure I wear my COROS heart-rate monitor as it means my data is more accurate, and checking my heart-rate is vital to ensure I’m staying in the right zones.”

One athlete who believes Yee can rise to the challenge is Tom Bishop, one of the leading GB elite triathletes of the past decade, who is now mixing racing with coaching. “I’ve trained and raced with Alex since 2017 and have admired his rise to global success,” Bishop says. “It was clear from the first day I met him that this lad could run.

“But also his tenacity and determination were what truly struck me. These traits will see him thrive in the marathon world. With the expert team, training partners and mentors around him, I do not doubt that Emile Cairess’ British debutant record will be under threat.”

It’s jumping a long way ahead, but should Yee’s marathon debut go to plan, would he consider an audacious bid at doubling up for the triathlons AND marathon in Los Angeles 2028? While USA’s Taylor Knibb competed in both the cycling time-trial and triathlons in Paris, the attrition of Yee’s potential events – totalling over 54km of hard-running – is some ask. USA’s Morgan Pearson has also hinted he might attempt the triple.

Even if the athletes are game, so much depends on the schedule. While the LA28 format hadn’t been finalised, World Triathlon were among the sports lobbying to be one of the first medal events of the Games. While track and field is being flipped with swimming to feature in the first week, if the men’s marathon is held back until the final weekend, it would perhaps provide the only schedule where it could possibly be considered.

“There are lots of factors that would need to go into that decision but my focus for LA 2028 is firmly to be in the best shape possible to defend my triathlon title,” Yee says. “I haven’t considered anything else.”

Elliott is in agreement: “It would be incredibly challenging. Not going to say no, but it would be an immense challenge to race at the sharp end of both at the same time.” One thing Yee won’t be doing is getting too far ahead of himself. Even the rest of the eyes on London on April 29th and a fascinating race in prospect.

Is running a marathon a good idea for triathletes?

Tom Bishop is a professional triathlete and BTF Level 2 qualified coach and part of the Tridot Coaching Community. He gives his advice on marathon training and cross-training as a triathlete:

Running a marathon is a great idea for triathletes. The fitness and discipline it takes to train and race a marathon will give you some great benefits for your triathlon season, especially if you choose a springtime marathon like London.

It will keep you focused throughout the winter months when it is more difficult to get out on your bike and could be used as a B race as you plan your Ironman preparations. Just give yourself enough time to recover from the marathon before you race again.

Additionally, all the hard work you’ve put in for the marathon build will set you up for a great run in a triathlon. The strength gained from the long run and marathon sessions will help to lift your goal pace for long-distance racing and you’ll have the confidence that you can get

How can triathletes cross-train for a marathon?

Marathon training doesn’t all have to be running. Plan with your coach the key run sessions you have in a week, like a long run, marathon pace intervals and strength work. Then use your recovery days to off-load the legs, like an easy swim or spin on the bike. Long rides will still give you the endurance fitness and physiological gains for the marathon.

Don’t forget to keep you swimming up as you enter the triathlon race season. It’s easy to neglect when focusing on a single discipline and you don’t want to lose all the gains you’ve made over the years. It doesn’t take many swims to retain the skills and fitness you have.

Also consider heading to the gym. Get strong and robust for the long hard runs you have, the last thing you want is to pick up an injury while preparing for a marathon before the season.

Inspired to up your running endurance with a new challenge? Take a look at our run training advice for more.