Challenge Henley in 10 hours? The Plan

I will be doing Challenge Henley this weekend, with a goal of doing it in 10 hours. This is an Iron distance race (3.8km swim, 180km bike, 42.2km run) and I am reasonably comfortable with what I’m able to do at the moment, having 2 recent Ironman races fresh in my memory – Ironman Switzerland July 10th (11:02) and Vineman July 30th (10:18). I will be taking some learnings from both those races into this one in order to try and take another 18 minutes off my time. I’m not going to swim much faster so I will need to gain time on the bike and the run. Here’s the plan – it will be interesting to look at this afterwards and see how close I get! If you happen to be online on Sunday you can track the progress of athletes in real time using the Challenge Henley Athlete Tracker.

Swim – 1:10 (may be lucky and do it a few mins faster)
Transition 1 – 2mins
Run – 3:25 (this is best case if all goes to plan)
Transition 2 – 2 mins
Bike –  5:20 (see plan below)

Total: 09:59

The swim and the run are pretty constant, but the bike offers the opportunity to ride more strategically. By saving energy on the bike, you set yourself up for a good run. There is no way that I will run a 3:25 marathon if I go too hard on the bike. Having said that, I know I have a little more in me on the bike based on my recent races, the questions is will I overdo it? Well, there is only one way to find out and that’s to do it! My plan for the bike is below. This is based on riding at specific power outputs and being pretty disciplined in not going too hard, especially in the beginning.

[You can scroll around the embedded spreadsheet below if you need to see the whole thing]


I will allow myself some flexibility in the 2nd half to push it a bit harder if I’m feeling good. The idea is to put in extra effort on the hills, where wind resistance does not play as much a role as on the flats & downhills. When you are going 40kph+, extra power output does not translate into a significant amount of extra speed.

As you can see, this plan has to be executed perfectly if I want to go sub 10. However, I will not stick to this plan “at all costs” for example if something goes wrong on the bike (something usually does), I just accept that and adjust the plan on the fly, in order to do the best that I can. After all, the main reason I do this is because I enjoy it, breaking 10 hours would just be a bonus!

If you’re also racing this weekend – good luck and enjoy it!

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