Reasoning behind the various intervals at just above ftp

I was curious what the goal was behind the use of the intervals that have you riding at around 102-105%
I see these across various plans. Is it just a way to get a more intensity in that single hour or something else?

From my own understanding and own training I was under the assumption going above your FTP would train a different energy system than training right at threshold or even a couple % below. You could miss out on the adaptions you’re after by going over that threshold. Obviuosly there is a reason to train above FTP, but I’m more specifically interested in this supra threshold level not vo2 intervals.

So… What gives? and why would they exist in Long Distance Tri specialty plans?

If you have a look at the workout description it’s usually pretty good for explaining the purpose of the session. In the case of working just above threshold it’s basically trying to gently stretch you beyond what you can currently do and thus raise your FTP. Plus it’s getting you accustomed to quite an uncomfortable intensity both mentally and physically - if you can handle longish intervals just above threshold then cruising along at ~75% for an IM bike leg will seem like a breeze :wink:

From an energy system perspective things aren’t shifting that much going from 95% to 105% FTP. It’s not like the moment you go above threshold one system shuts down and another kicks in. If all your sessions were like this then yes you would be missing out on some adaptations - for long distance tri then specifically you’d be missing out on building the fatigue resistance to do multiple hours at a high % of FTP. But that’s why there’s variety on the training plan, to maximise the training adaptations you get. If you decided to train the way you’re going to race for example, and just do all your sessions at 70-80% of FTP, then you’d have a ton of fatigue resistance and endurance but you’d be missing out on all the training adaptations you get from working close to and above threshold.