Every triathlon forum on the internet has the same thread. Someone posts a breakthrough race result, everyone asks what they did, and within a week half the group is trying to replicate the programme. The sessions get shared. The weekly structure gets copied. And almost nobody gets faster from it.
This is not because the plan was bad. It is because the plan was built for someone else.
The Plan Is a Solution to a Specific Problem
A training plan is not a universal recipe. It is a specific response to a specific athlete's physiology, training history, lifestyle constraints, and current fitness profile. Every decision in that programme, from the session structure to the intensity targets to the weekly volume, was made in context. Remove the context, and you are left with a list of sessions that may or may not address anything your body actually needs.
Two athletes with identical threshold power can have completely different metabolic profiles. One might be aerobically dominant: a high first threshold, compressed upper zones, and limited capacity above the second threshold. That athlete needs targeted high-intensity work to raise their ceiling. The other might be glycolytically dominant: a low first threshold, rapid hydrogen ion accumulation, and a wide gap between their two thresholds. That athlete needs the opposite. More sub-threshold volume. More time developing oxidative capacity so the aerobic system can support what the top end is already producing.
Give both athletes the same plan and one of them gets worse. The sessions that develop one athlete's weakness actively neglect the other's. This is why understanding your metabolic profile matters, and it is why the plan someone else succeeded on tells you almost nothing about what will work for you.
The Programme Changes Because the Athlete Changes
Olav Bu, the sports scientist behind Norway's Olympic triathlon programme, has made this point directly. When asked about the programmes he designs for athletes like Kristian Blummenfelt and Gustav Iden, his answer is unambiguous: the programme is never the same twice. It changes and it changes and it changes, because the athlete is changing. Different experience, different race data, different physiological responses all feed back into the next iteration of the plan.
Bu describes what he calls the "individual performance signature." When an athlete truly performs at their best, there is a specific combination of metabolic, mechanical, and physiological factors that is unique to that person. The coach's job is to identify that signature and build training around it. You cannot import someone else's signature any more than you can import their genetics.
This applies at every level, not just the elite. The principles of the Norwegian programme, like sub-threshold emphasis, intensity discipline, and long-term aerobic development, are broadly transferable. The specific prescription is not. A professional doing 30 hours a week with laboratory-guided sessions is solving a fundamentally different equation to an age-grouper training eight hours around a full-time job.
Why the Internet Gets This Wrong
The appeal of copying a plan is obvious. If someone ran 28 minutes faster in their half Ironman, the implicit assumption is that the training plan holds the answer. Replicate the plan, replicate the result.
But training outcomes are multi-factorial. The plan is one variable. Sleep, nutrition, total life stress, years of aerobic development, genetic predisposition, and execution quality are all variables too. You are looking at the output of an equation with a dozen inputs and trying to recreate it by copying just one.
This is also why your fitness is better understood as a curve than a single number. Two athletes who look identical on a threshold test can have completely different shapes to their fitness when you examine the full power-duration or velocity-duration curve. The ratios between short-duration and long-duration capacity tell a story that no single number captures. Two athletes with the same threshold need very different training if their curves look different underneath.
What Actually Matters
The training that makes you faster is the training that addresses your limiters, respects your lifestyle capacity, and is structured around your physiology. Not someone else's.
That starts with knowing where your first and second thresholds sit and understanding the relationship between them. It means building a picture of your fitness across multiple durations and using the shape of that picture to identify where the gains are. For one athlete, the answer is more aerobic development below the second threshold. For another, it is targeted work above it to raise the ceiling. The solution depends entirely on the problem, and the problem is different for every athlete.
It also means accepting that the right plan changes as you change. There are no magic workouts. A session that drives adaptation in March might become maintenance by August because your body has responded and the limiter has shifted. What matters is not the session on paper but whether that session addresses what your physiology currently needs.
The Uncomfortable Truth
Most athletes do not want to hear this. They want to believe there is a secret session or a hidden programme embedded in someone else's success story. It is easier to follow a plan, or hand the job to an app, than to do the messy, iterative work of understanding your own physiology and adjusting as it evolves.
But that iterative work is exactly what separates athletes who plateau from athletes who keep improving year after year. The plan that works is the one built for you, tested against your data, and updated as you change. Everything else is someone else's solution to someone else's problem.
Training plans are answers to specific questions. If you do not share the question, you will not share the result.