You've committed. You've written it on the first page of your brand-new notebook. It's a notebook with swim, bike and run graphics on the front, along with some inspirational quote. Something along the lines of 'It's supposed to be hard. If it wasn't hard, everyone would do it... The hard is what makes it great.' 

You've yet to decide if it's great or not. 

You've yet to decide if it's hard. You've yet to decide which event you're signing up for. All you've decided is you want to call yourself an Ironman, and nothing is going to stop you. 

However, before you dip your toe in the water, or clip into your bike shoe, or squeeze into your trainers, you need to enter an event. Training is easier with an incentive. You need a goal to chase. 

And so here you are. Clicking between various races on the Ironman website. Will it be Ironman Nice? Co-host of the World Championships, but a hilly route. How about Ironman Barcelona? A flatter option, and oh the opportunity for travel afterwards. Or Ironman Switzerland? You can't get much more iconic than a marathon against a backdrop of glaciers. So many options. It's all a little overwhelming and you haven't even got there yet. 

Whatever event you chose, it needs to be right for you. It goes without saying, these races are costly. The average Ironman entry will put you back £500, and that's before travel, hotels and insurance. It also goes without saying you'll be out there for a while. The average Ironman completion time is 13 hours ... you don’t want to be trailing around a course you hate. You want to feel inspired and motivated. This is the culmination of months of hard training. It is a day you'll remember forever. 

So, choosing the perfect event is crucial. It needs to motivate and excite you, both in training and on the day. Alas, worry not. We have you covered. Here's our top ten Ironman events of 2025. Take your pick. 

1. Ironman Kalmar 

Swim: Ocean. Bike: Flat. Run: Flat. 

A friendly course tickled with seaside charm. Typically, almost half of competitors are first-timers – a whooping 41% in 2019. And it’s no wonder why. Spectators out in full force. A staggering Scandinavian landscape. Crossing the spectacular 6km-long bridge to the island of Oland. And after all of that? One of Europe’s biggest finish line parties. You’ll be cheered on from start to finish and then encouraged to celebrate in style.  

Will Kalmar be where you make your debut? 

2. Ironman Nice. 

Swim: Ocean. Bike: Hilly. Run: Rolling. 

 As the co-host of the Ironman World Championships, you’d expect to find the big guns here. But as well as the top-level age groupers and professional athletes, you’ll find A LOT of hills. 2400m worth.  It’s a course set to test your fitness, especially on the bike. But as you pant and wheeze and question why you didn’t choose something flatter, your eyes will be treated to some amazing scenery. The gorgeous villages of the Parc Naturel des OreAlpes d’Azur are a standout for most.  

 Will Nice bring out your best? 

 3. Ironman Barcelona 

Swim: Ocean. Bike: Flat. Run: Flat. 

 I don’t think anyone can call Ironman gentle. But on the spectrum, Barcelona is probably nearer the gentle end. A sea swim in a bay on Spain’s eastern coastline. A fast bike course. A flat run. It isn’t surprising this course has racked up many sub-8 hour finishes over the years. But as you whizz and zoom, take a glance up from your power meter every once in a while. Barcelona hosts incredible architecture galore. Gaudi’s unfinished cathedral – La Sagrada Familia – is a real highlight. And we can’t not mention the nightlife. If you want a good afterparty ... 

 Has Barcelona tickled your fancy?  

 4. Ironman Switzerland Thun 

Swim: Lake. Bike: Hilly. Run: Flat. 

 Back in the day, Ironman Switzerland took place in Zurich. But no one has disputed the change of location. You can’t argue with the opportunity to race under the shadow of glacial mountains. You begin in Lake Thun, then whined through Spiez and into the Gurbe Valley. This course really is a favourite with athletes from around the world. And Thun’s got the credentials to prove it. They’re rated ‘the world’s #1 bucket list race’ on Ironman’s social media accounts. Thun must be doing something right.  

 Is Switzerland calling? 

 5. Ironman Frankfurt 

Swim: Lake. Bike: Rolling. Run: Flat. 

 A Mediterranean masterpiece created by some skilled route planners. Frankfurt isn’t a bad bet if you’re looking for a shot of a personal best with a side-serving of Mediterranean sun. The waters of the swim course wash onto 900 meters of golden sand beaches. The bike course treats you to scenic villages and views of the impressive ‘Mainhattan’ city skyline. The run course is flat and fast, propelling athletes down the paved promenade of the Main River. Frankfurt has been the site of hundreds of PBs.  

Will it be where you set yours? 

 So, what will it be? 

 Flat and fast or steady and scenic? Under the shadow of mountains or against a city skyline? Popular with the pros or bustling with first-timers? Share your thoughts in the comments. 

 Once you've signed up to your Ironman, it REALLY is time to start training though. That swim, bike, run isn't going to complete itself.