I have been spending the last few weeks reading two books that, in different ways, sit inside the modern Norwegian training conversation.

The first is Marius Bakken’s The Norwegian Method Applied, which traces the logic behind threshold-controlled endurance training and the now-famous double-threshold model. The second is James Copeland’s Norwegian Singles Method: Subthreshold Running Kept Simple, which takes some of the same principles and adapts them for runners with normal lives, normal schedules, and no realistic desire to turn every training week into a laboratory experiment.

Both books point in the same general direction: controlled sub-threshold work matters.

Not heroic tempo running. Not “smash yourself just below threshold and hope for the best.” But disciplined, repeatable work in the space below the point where the session starts to run away from you.

Then, almost perfectly timed, Matti Rowe’s Gravel God Cycling article “Sweet Spot Training Isn’t That Sweet” appeared in my Substack feed.

Rowe’s piece is sharp, funny, and deliberately provocative. The tagline more or less tells you what you are getting: Sweet Spot is “made up,” “makes you slower,” and “science hates it.” That is good internet writing. It is also, I think, deliberately overstated.

His real target is easier to agree with: the over-marketed version of Sweet Spot training, where athletes are sold the idea that enough “comfortably hard” work can shortcut the long, unglamorous process of building endurance. He also points to a genuine problem in cycling: if your FTP is set too high, what you think is Sweet Spot may actually be threshold work in disguise.

So yes, there is a critique here worth taking seriously.

But “science hates it” is where the argument becomes too neat. Bakken’s entire threshold model is built around controlled intensity, lactate feedback, and repeatable sub-threshold work. Copeland’s book is an attempt to translate that logic for normal runners. Steve Magness has also written repeatedly about the danger of turning training models into rigid camps rather than understanding the underlying stimulus.

In other words, science does not hate the middle.

Bad coaching should hate the uncontrolled middle.

So there I was, reading Bakken and Copeland making the case for controlled sub-threshold work, while Rowe was making the case that Sweet Spot is largely a trap.

At first glance, those views seem completely opposed.

One says the middle is central.

The other says the middle is the problem.

But the more I thought about it, the more I realized they are not really arguing about the same thing.

Rowe is attacking the uncontrolled middle.

Bakken and Copeland are describing the controlled middle.

That distinction is everything.

Because the problem is not that athletes train in the middle. The problem is that they live there without control. Their easy sessions are not really easy. Their hard sessions are not really hard. Everything becomes moderately uncomfortable, and over time that creates fatigue without clear progression.

But that is not an argument against the middle.

It is an argument against an uncontrolled middle.

The more interesting question is not whether moderate training is good or bad. The better question is:

Can we control this intensity precisely enough to make it repeatable, productive, and recoverable?

That is where the debate changes.

Because when you look past the labels, the lesson from Bakken and Copeland is not “avoid the middle.” The lesson is almost the opposite: learn how to use the middle properly.

Bakken’s work frames threshold training around control, lactate measurement, repeatability, and durability. Copeland’s contribution is to take that threshold-control logic and turn it into something more usable for runners who are not training twice a day or testing lactate after every interval.

That is what this article is about.

Not Sweet Spot as a marketing slogan.

Not polarized training as internet dogma.

But the controlled middle: when it works, why it works, and why the so-called black hole is usually not a zone problem, but a control problem.

Polarized training became popular for a good reason.

Most athletes need protection from themselves.

Left alone, many runners and cyclists drift into the same pattern: easy days become a little too ambitious, quality sessions become survival tests, and recovery days become disguised aerobic workouts. They are never truly fresh, but they are also never training with enough clarity to move the needle.

So the polarized message was useful:

Slow down. Make easy easy. Stop racing every session.

That advice has helped a lot of athletes.

The problem comes when a useful guardrail becomes a rigid ideology. Somewhere along the way, “most of your training should be easy” turned into “the middle is bad.” That is a much weaker argument.

The research picture is more nuanced. Reviews of elite endurance training show that many successful athletes spend a very large proportion of their time below the first threshold, but their overall distribution often looks more pyramidal than a simple internet version of polarized training would suggest. A large low-intensity base is usually there, but so is a meaningful amount of controlled moderate work.

That does not mean polarized training is wrong.

It means polarized training is a useful guardrail, not a universal ban on the middle.

The middle is not automatically a black hole. It becomes a black hole when it is too hard, too frequent, poorly placed, and not controlled by pace, power, heart rate, lactate, RPE, or common sense.

Part of the confusion comes from language.

“Sweet Spot” can mean very different things depending on who is using the term.

In cycling, it often refers to work around 88 to 94 percent of functional threshold power. In running, people may use it to describe anything from marathon effort to half-marathon effort to “comfortably hard” tempo running.

In practice, many athletes interpret Sweet Spot as:

That is where the trouble starts.

If an athlete repeatedly pushes close to their upper threshold, the cost rises quickly. Lactate accumulates. Breathing becomes forced. Muscle tension increases. The nervous system takes a hit. The session may look controlled on paper, but the body experiences it as a serious stressor.

Do that too often and the internet critics are right: the middle becomes a hole.

But bad Sweet Spot is not the same as controlled sub-threshold training.

That is the key distinction.

Rowe is right to attack the lazy version of Sweet Spot: the idea that you can live in a moderately hard zone and somehow bypass the need for proper endurance development. But the Norwegian-style sub-threshold approach is different.

The goal is not to prove how hard you can train without calling it hard.

The goal is to accumulate meaningful aerobic work while staying below the point where the cost of the session starts to escalate.

That is a very different idea.

The middle is not magic.

And it is not poison.

It only works when it is controlled.

Polarized training is not wrong. For many athletes, it is the first lesson they need. Slow down. Stop turning every session into moderate mush. Protect the easy days. Create contrast.

And Rowe’s Gravel God critique is useful because it attacks a real problem: the over-marketed, poorly controlled version of Sweet Spot training that convinces athletes to live permanently in “kind of hard.”

But polarization is a guardrail, not a complete philosophy.

The question is not whether the middle is good or bad.

The question is whether you can control it.

In Part 2, we will look at what that control actually looks like in practice, using Copeland’s Norwegian Singles model and his sub-threshold pace table.