Race Hub · First-timer's guide
IRONMAN 70.3 Bolton
Sunday 6 June 2027, Bolton. A lake swim at Pennington Flash, a genuinely hilly loop through the Lancashire countryside, and a multi-lap run into Bolton town centre. Here's the real course, and a pacing plan built against its actual elevation, not a flat-or-hilly guess.
The Bike Course
The hills are the whole story.
The bike is a single loop out of Bolton into the Lancashire hills, with 840m of climbing across 90km. There is no single mountain here; it is repeated, honest climbs, and it is the drip-drip of them that catches first-timers out. We pace you against the elevation from the official IRONMAN bike GPX, not a flat-or-hilly guess. Ride the hills within yourself early and you will still have legs for the run.
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 Bolton 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.
Bolton in early June is usually mild but can be cool or wet, only nudge to Warm if it is genuinely warm on the day.
Power-to-weight body composition
Bolton is a climber's course, honest hills all day, and on those climbs your speed is governed by power-to-weight: the watts you can hold for every kilo you carry up the road. Same power, less weight, and you go up faster, which is why body composition matters more on this course than on a flat one.
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