Race Hub · First-timer's guide
IRONMAN Wales
Sunday 13 September 2026, Tenby. The full one: a two-loop 3.8km sea swim off North Beach with the famous zig-zag climb to transition, two laps of Pembrokeshire with 2,369m of climbing, and a four-loop marathon through the medieval walls that climbs over 500m itself. Widely rated one of the toughest IRONMAN courses anywhere. Here is the real course, and a pacing plan built for the full distance, not a doubled-up 70.3.
The Bike Course
Pembrokeshire never lets you settle.
Two loops and 2,369m of climbing across 178.3km on the official GPX, with no single mountain to point at: the toll comes from an endless chain of 60 to 75m climbs, and the sharpest of them stack up in the second half of each lap. On a full-distance day you ride all of it at a discipline that feels almost too easy, because the marathon that follows is hilly too. We pace you against the real elevation at full-IM intensity, not 70.3 effort, so there are still legs left to run on.
Pacing Calculator
How do your numbers stack up right now?
Built for first-timers. You don't need to know your FTP. A couple of honest inputs and we'll model your day against the real Wales course.
Your Critical Swim Speed. We add for open water & wetsuit.
Don't know your CSS? Click HereUsed with your weight for a power-to-weight read. Not stored anywhere.
Average km/h on a recent long ride, of similar race distance and terrain, at race pace effort.
Your standalone half time, h:mm:ss.
Tenby in September has raced between 1 and 19°C in recent years. Cool / mild is the honest default, and pack for cold.
Power-to-weight body composition
Wales climbs from the first hour to the last: over 2,300m on the bike and another 500m on the run, and on every climb your speed is governed by power-to-weight: the watts you can hold for every kilo you carry up the road. Body composition matters more here than on almost any course in our library.
These are just mathematical outcomes from your height and weight, not a judgement on your body, and the maths can't tell how much of your weight is muscle. Any change should come from better fuelling and training, never restriction or dropping weight for its own sake, under-eating to chase "race weight" costs you more fitness than it buys. Whether it applies to you at all, and what a healthy target looks like, is exactly what our coaching team, with Adam on nutrition, work out with you 1:1.
Don't go it alone.
These headline numbers are a great start, but race day is bigger than a set of splits. What gets you to the line ready, and across it in the best possible shape, is a coaching team in your corner: mapping and running the whole journey with you across training, strength and conditioning, nutrition and race-day strategy, built around your life and adjusted as you go. That is exactly what Team TC does.
Apply for 1:1 coaching with TomBefore race day