Slaying the dragon: Our top tips for conquering Ironman Wales

Ironman Wales, renowned for its challenging course and breathtaking scenery, is a formidable test of endurance. 

Finishing the Tenby-based course calls for physical fitness, mental fortitude and astute race-day strategy. The DNF (did not finish) rate of 8-12% in recent years is relatively high. 

We consider it one of the world’s toughest Iron distance triathlons, so a good triathlon time will be slower than usual. The median finishing time was 13:55:25 in 2024 with a 17-hour cut-off. 

From navigating the turbulent Irish Sea to conquering the relentless hills of Pembrokeshire, here are the best tips to help you tame the Welsh dragon.

The Irish Sea swim

The 2.4-mile, two-loop swim from North Beach can be a daunting start. The key is to ensure your have the requisite skills and confidence. 

Prepare for the chop

Sea conditions can range from millpond calm to significant chop. Be prepared for rough water. 

Practise open-water swimming in various conditions to build confidence. 

Bilateral breathing is a crucial skill to develop, allowing you to breathe away from incoming waves.

Pick the right gear

You’ll need one of the best triathlon wetsuits since the average water temperature in Ironman Wales’ late September slot is 61 degrees Fahrenheit / 16 degrees centigrade. 

Because the swim starts early, the best swimming goggles for race day will have a clear or light-enhancing lens. 

See clearly

With a long course and potentially large swells, frequent and effective sighting is vital. Identify prominent landmarks on the shoreline during your warm-up to aid navigation.

The Aussie exit

A unique feature is the “Australian exit” – a short beach run between the two laps. 

Use this opportunity to regain your composure and receive a boost from the cheering crowds.

The long run to T1

Be prepared for the approximately 1,000m run from the swim exit to the first transition (T1). 

Many athletes opt to have a dedicated pair of shoes waiting to make this journey more comfortable. 

Don’t rush this section. Bring your heart rate down and steel yourself for the bike leg.

The Wild Welsh bike

The 112mi / 180km bike course is where Ironman Wales earns its reputation.

With over 8,000ft / 2,500m of elevation gain on buffeting side winds, proper pacing, bike handling and gearing are paramount.

Climb and descend steadily

The course is a relentless series of climbs and technical descents both with gradients as sharp as 15-25%. 

Pace yourself on the ascents, especially on the notorious “Heartbreak Hill” in Saundersfoot.

It’s a steep, crowd-lined climb that you’ll tackle twice. 

Avoid the temptation to push too hard here; save your legs for the marathon. 

If you use a power meter, try to stay below Functional Threshold Power (FTP) on the climbs where possible. Once you exceed FTP, you use much more carbohydrate, which could drain your glycogen stores and make you more likely to bonk on the run. 

Descend with care, as some roads can be narrow and technical. An Ironman training camp could help you perfect pacing on the hills and improve your descending. 

Go big at the back

A standard road bike cassette may not be sufficient. 

Use a cassette with larger sprockets to allow for a higher cadence on the steepest climbs, saving your leg strength. 

Shimano road groupset users could pick an 11-34t or 12-34t cassette while SRAM road groupset users could go as low as a 10-36t. Before doing so, make sure your rear derailleur has sufficient capacity. You’ll probably need a long-cage option.

At the front, age-groupers will be better off with a double chainring, so you can drop down to the easier gear afforded by an inner chainring. 

Cheat the wind

The coastal sections of the course are often exposed to strong winds. Be prepared for crosswinds and headwinds that can sap your energy. 

Hold as aerodynamic a position as possible in to the headwinds and economise your power output. 

When you have a tailwind, you can afford to sit up slightly and put more power down. 

Make a nutrition strategy 

The demanding bike leg requires a well-practiced nutrition and hydration plan. 

Start fueling early and consistently throughout the ride. 

The aid stations are well-stocked, but be sure to have trained with the on-course nutrition or carry your own preferred fuel, such as energy gels. 

Beforehand, a carb-loading strategy will certainly help. 

Save weight

Due to the elevation of the Ironman Wales bike leg, the weight of your triathlon bike will be influential. 

While one of the best road bikes could be quicker up the climbs, out west and north, the course presents several opportunities to rip along in the tri bars and gain time on the most optimised road bike set-up. 

Therefore, if you have a tri bike, your best bet is to drop weight off it. Cheap ways to do this are upgrading the inner tubes (if using) to TPU or latex inner tubes and switching to lighter tyres. 

Don’t go too light though. The grippy Pembrokeshire roads make mincemeat of fragile, time-trial tyres. A fast rolling, all-round road bike tyre will be less likely to puncture, especially when set up tubeless.

It sounds obvious but if you have any unused storage or hydration system or bottle cages on your bike, don’t forget to remove them. 

The best triathlon bike wheels for the course will be mid-depth, lightweight hoops – leave the deep-sections rims at home!

You could also save weight by upgrading from an alloy to carbon cockpit.

The Tenby run

The four-lap, 26.2-mile run course through Tenby and its surroundings is anything but flat. You’ll climb 1,640ft / 500m in total. 

However, the incredible spectator support can carry you through the toughest moments.

Pace the hills

The run features significant elevation changes on each loop. 

Don’t be afraid to walk or slow your pace on the inclines to conserve energy. 

Use the downhills to recover and maintain a steady rhythm.

Make sure your triathlon running shoes have decent grip, particularly if conditions are set to be greasy. 

Break it down

The four-lap format allows you to break the marathon into manageable segments. 

Focus on one lap at a time and let the buoyant crowds give you a lift each time you pass. 

Due to the undulations, it will be hard to pace yourself by speed. Heart rate training zones and Rate of Perceived Exertion will probably be more insightful. 

Dig in and make adjustments if necessary

After a brutal swim and bike, the marathon will test your physical and mental resolve. 

Pay close attention to your body’s signals and adjust your pace and nutrition strategy accordingly. 

Our writer underlined how important this was to her finishing a very demanding Ironman Leeds. 

Soak in the atmosphere

As tough as Ironman Wales is, the backdrop (think of Pembrokeshire as a more rugged Cornwall) and passionate support should make it a memorable occasion. 

Remember to soak in the atmosphere on the Esplanade finish line before sampling Tenby’s lively hospitality. 

More general race preparation tips

Do a recce

If possible, familiarise yourself with the course beforehand. 

Driving or cycling sections of the bike course and walking parts of the run course can help you develop a pacing strategy and draw attention to any course hazards. 

If you can’t do a recce, it’s worthwhile to input the course into online software like My Windsock or Best Bike Split.

Prepare for rain and shine

The weather in Pembrokeshire can be unpredictable. 

Be prepared for rain, wind, and sunshine and pack appropriate gear. 

Include triathlon sunglasses and a lightweight waterproof cycling jacket in your race bag. 

If you’ve entered or plan to in future, follow 220 Triathlon contributor Matt Baird’s training diary for Ironman Wales.