Question: what power zones/levels should I be targeting during my Ironman® training?

Rich Strauss: The power training world speaks the power language described by Coggan and Allen in “Training with Power,” the WKO+ software, etc. This is based on Functional Threshold Power (FTP), or your average watts for a 60′ time trial effort. Training and racing zones are then prescribed as a percentage/fraction of this power.

In my experience, the zones described in the book above and in WKO aren’t very descriptive and are too broad. This is how we work the issue with our athletes. Below are percentages of FTP.

• 70-75% = Ironman-flavor intensity. Per my earlier post on this thread, we spend more time here closer to the race, as this is where you’re going to race at.
• 80-85% = Half IM intensity, spend more time here closer to an HIM. It’s also the default training zone of our athletes, as it really, really racks up the training stress of a ride very quickly. Very time efficient place to sit. It’s described as “Sweet Spot Training.”
• 95-100% = “make you faster” intensity. We do lots and lots of intervals here, in order to drive up FTP, making the athlete faster at all intensity.
• 120% = Vo2 Max intensity that we usd for very special purposes in our off-season.

In short, the answer to your question is “it depends on what you’re trying to achieve, where you are in your season plan.” You dial in different zones to achieve different effects and you target different effects depending where you are in the your season.