Get ready for Ironman: Conquer the swim
You can't win the race on an Ironman swim, but you can certainly lose it. Here's how to prep – and quell your nerves – for the 3.8km starter on your 226km day of destiny.
Eight-six, 85, 84… log onto the website of any Ironman event and you’ll see a countdown to race day. Even with nearly one hundred days to go until the 2025 edition of Ironman Wales, it’s a reminder that time is ticking and – with three disciplines to train for – every day counts when you’re preparing to face the world’s toughest endurance sport.
Not forgetting the strength and conditioning sessions, transition practise and time spent looking at shiny bike upgrades online…
This month, we’ve tapped up the 2023 Ironman Wales winner, Nikki Bartlett, and a host of top coaches and age-groupers for their proven tips on making swim training fun, how to prep for the open water and what to do come race-day, whether that’s Ironman Wales, the Outlaw or any other major race you’ve entered this season and beyond.
Before that, let’s whet our appetite for what awaits on race day for anyone racing Tenby. “The Ironman Wales swim is so spectacular because Tenby’s elevation over the start line adds an atmosphere that other venues can’t compete with,” says Graham Wadsworth of the Bristol-based personal trainers, My Life PT.
“Even famous starts such as Ironman France in Nice don’t have the cliffs, the beach or the waves that make Tenby so special.” Inspiration rising, let’s move onto the expert tips for taming that 3.8km swim…
Here’s how to conquer your Ironman swim
Head to the sea
“It’s cliche that you can’t win an Ironman on the swim, but you can 100% lose it,” says Graham Wadsworth, who completed Tenby in 2023 in a time of 10:25:40 to finish fifth in the M40-44 age-group.
“At Ironman Wales, many athletes don’t make it to T1 on a rough sea year. For the first discipline at Tenby, focus on open-water swimming and training in the sea before race day.
“Take the time to practise in the sea somewhere in the summer. Go out on days that aren’t flat conditions and get familiar with sighting in rough water, currents, waves, beach entries and exits.”
Go in with confidence
Tenby’s North Beach might be a natural bay, but it’s still exposed to the whims of the Atlantic Ocean, as thousands of athletes will recall since the race started in 2011, including British pro star and Rouvy-sponsored athlete Nikki Bartlett, who won the 2023 edition of the race.
“The sea at Ironman Wales can literally throw currents, swell and waves on race day. My biggest tip is to get practising in similar conditions, even if it’s a sea that’s more local to where you live or on any family holidays you have coming up.
“Even getting used to the taste of sea salt for over an hour. The best preparation is going in with confidence that you can tackle and get through whatever race day looks like.”
Know your course
The ‘Australian exit’ in Tenby is certainly a blessing, the chance to get out halfway through for a breather and a lowering of the heart rate.
This two-lap swim format is also in operation at Ironman Leeds but with an in-water lap that keeps you in Waterloo Lake for the entirety.
The Outlaw has an out-and-back swim course, meanwhile, and there’s a handy four laps at both The Northumbrian and the UK Ultimate Triathlon, which is where I faced my one and only Iron-distance race in 2018.
Race-day advice
That swim was a largely serene 1:37hr in the water, but for Ironman Wales I know that my success at Tenby will also depend on the weather gods – all I can do is physically and mentally prep for every eventuality come September.
“Knowing you have been in similar race day conditions ahead of the race is so important and helps build your confidence,” adds Bartlett, the Cheltenham-born sports science graduate who didn’t wholeheartedly convert to triathlon until she was 25.
“A good tip is to look online or YouTube for visual images of the sea swim course and start looking at landmarks you can sight. When it’s choppy, it’s really hard to see the swim buoys so use the famous lighthouse in Tenby as a sighting option.”
Pool practise
Staying at the back and to the side has long been my advice for mass open-water starts, but there other swimmers can’t be avoided altogether on pinch points such as buoys. “If you struggle with people around you, get used to this in training,” advises Bartlett.
“You can do this in the pool by starting three abreast in a lane and all start together. This will get you used to being hit and the process of keeping calm and carrying on.
“You can practice a lot of open-water skills in the pool, including sighting a couple of times per length, arm cadence work to help with choppy conditions and drafting on feet and hips.
“Another tip on swim starts, if you get really nervous – and this helps me a lot – is counting to 10/20/30 on repeat until you start to feel calmer.”
Build those bricks
“The swim/bike brick is often the brick session that is hardest to replicate or often missed,” adds Bartlett, who progressed from being an age-grouper to finishing fifth at the 2024 Ironman World Champs in Nice.
“But, if you can perform it, it’s a really good brick session to stimulate and is maybe easier than you thought. It doesn’t need to be a ‘strict’ brick, more just getting used to getting out of a lake or pool and going into a hard bike.
“You can take your bike to the pool or lake and try to minimise faffing in between. If it’s unsafe to leave your bike, sometimes I do a ‘loose’ brick where I go for a hard swim session then drive home and have my bike all set up on the turbo.
“If you’re using a platform such as Rouvy, have the app ready to go with the course picked and workout uploaded. Bricks also allow you to practice race nutrition at race pace.”
Bring the fun
Indoor pool swimming has always bored me witless, which might explain why I’m always one of the last athletes to exit the water come race day. To bring both fun and focus, Wadsworth recommends adding descending time sets into your swim sessions.
“For example, do 50 metres off descending recovery – 50m off 75sec, 50m off 74 sec, 50m off 73sec… keep going until you can’t make the going time.
“Much of the set might be at a comfortable pace, allowing you time to focus on technique and achieve a base of aerobic development.
“Towards the end it’ll get very, very hard, however, pushing you to your current limit and spiking all those happy hormones you get from feeling like you’ve challenged yourself.”
Sight for success
My sighting on the swim – or ability to swim in a straight line – has long been one of my many multisport malfunctions, so much so that I nearly swim around a third longer than I need to in races.
For a 750m sprint-distance race, that’s frustrating. For Ironman, in battle against both the 2:20hr cut-off and waves of Tenby, that could crush my day before it’s really begun.
“Snaking or banana-ing in the water is often due to your hands crossing at the front and pushing the water slightly outwards on each stroke rather than straight backwards,” says 220 Triathlon’s editor and qualified open-water swim coach, Helen Webster.
“You can diagnose this yourself as you swim: if you are curving left for example, is your right arm crossing over at the front? Also try not to lift your head as high when breathing/sighting.
“The higher you lift your head, the more your legs will drop and create drag. Think ‘crocodile eyes’… Though if the waves are high in Tenby, you may find yourself having to sight/breathe a bit higher anyway!”
Technique analysis
Getting advice on technique from a qualified swim coach can reap huge benefits on race day, yet it’s something I’ve very rarely done in my tri career. An analysis from Helen gives me plenty to think about, including tweaking some long ingrained habits.
“At the moment, you breathe to the same side on a count of four. Play around with different patterns of breathing to see if you can feel more relaxed.
“Breathing every two would allow you to relax and slow things down as you’re not waiting so long for a breath – this might help in the adrenaline of a big sea swim event.
“Try breathing to the other side sometimes in training too – versatility is useful if the waves start coming at you on your preferred breathing side.”
Slow down to speed up
Knowing that I’ve done the 3.8km Tenby swim before at the Long Course Weekend is giving me some confidence, but that was in relatively serene conditions and I still felt like I’d wrestled with Giant Haysticks before my exit into the embrace of a bag of chips, not an 180km bike leg.
“You seem to be using a lot of energy on the ‘return’ part of the stroke and it looks like you’re fighting the water,” adds Webster during my swim analysis.
“The wetsuit needs to fit so it’s snugly up into the armpits or it’ll feel restrictive and you’ll end up having to work hard to move your arms around.
“Slowing down and not windmilling the arms through the stroke as fast will allow you to focus more on the catch and pull under the water.”
Stop the shivers
“It’s extremely common for athletes to struggle in cold water – I definitely do,” adds Bartlett. “The shock of the cold water can send your heart rate spiking and lead to panicking at the start of the race.
“Finding ways to minimise, prevent or overcome this without stopping is possible, though. You can do a lot of acclimatisation at home with cold showers leading into a race.
“Consider using two swim hats as well, although practise doing this. I hate the neoprene hats that go under your chin, but some people love them.”
Matt’s stats: How our writer has fared in May (and April)
- Swim: 3.5km (1km in April)
- Outdoor bike: 120km (68km)
- Indoor bike: 7.5hrs (2hrs)
- Run: 62km (49km)
- Vo2 Max: 50 (50)
- BMI: 24 (24)
Key swim buys to conquer the Ironman
Here are some of Matt’s major kit buys for a long-distance swim event:
Body Glide
Swimming for two hours in salty water can lead to a painful chafing experience, so don’t forget the pre-swim lube. Body Glide is a proven soother (£11.99 for 22g).
Aphotic Goggles
The low sun on race morning can make sighting even harder on the swim. These photochromatic goggles from Huub (£54.99) help to minimise glare from sunlight.
Travel sickness bands
The motion of open-water swimming can make you feel nauseous. Whether psychosomatic or not, these £2.99 travel sickness bands from eBay have long helped me.
Next month, we’ll be focussing on the Ironman bike, including staying comfortable, aerodynamic wins and how to build core strength ahead of Ironman race day.
Matt Baird
Editor of Cycling Plus magazine 
