My Max HR on the bike is about 185-190. I have it set to 188 in my training software. If you do the standard Karvonen formula for heart rate percentages then Roth was 62% and my Australian Ironman races around 69%. My planned racing heart rate of 135-145 gives a percentage range of 64-71%.

If I just calculate a raw percentage of maximum heart rate, then Roth was 70%, Australian Ironmans were 76% and the 135-145 range is equivalent to 72-77%. Not sure which is the most useful way to consider it. Probably more important just to be consistent in how you compare your figures to mine.

I also decided to have a look at the percentage of FTP I was considering working at for power. In Roth my average power was around 70% of my FTP. The sort of range I’ve been talking of working in of 220-250 watts would be about 73-83% of my FTP. One caveat to note is it’s been a while since I tested FTP- I’m not sure of the accuracy!

I’d consider working above 80% of FTP to definitely be too hard for an Ironman, so whilst it might seem reasonable in heart rate terms I would likely pay the price. I think I’m well enough trained to work in the 75-80% FTP region for power and still run well, so I can approach the higher powers, but have to be cautious.

HR figures certainly may seem low, but the aim is to have the fastest bike split that enables me to run well. I could ride 180km faster than I do in an Ironman. If I rode at that pace though my run will fall apart though. Lanzarote was a very practical demonstration to me of how significant time loss on the run portion is. Whilst not a consequence of pushing too hard not being able to run well lost more time than any other part of that race.

Russ