I think the ISM method is different - lower intensity and higher volume than Steve’s closer to sweet spot HR governed “tempo”.
I think Steve is brilliant but I also suspect that all of his metabolic testing and LBP is pseudo science.
I did Steve inspired training - a January-March build. I built out to 4x20minutes which was 2 hours on the trainer and a enough for me. (Yes, I know some guys build out to 4x30min or more.) I hit my highest numbers and felt like I had my best fitness ever in June after adding some intensity.
Why does it work for lower volume athletes?
I suspect that Steve’s methods are more akin to Nowegian lactate controlled training. In sum, it’s threshold training light but you can do more of it with the HR limiter or lactate control (Norwegian). And, I think it all comes down to training load - Steve’s method produces the highest sustainable training load for a low volume amateur. Remember that this started in his indoor cycling gym. He would not train an elite with 20 hours a week in this fashion (I don’t think). It would look more traditional.
Whilst Pog is an incredible talent, one of the reasons for him being on a completely different level at the moment to Remco and Jonas is how much training time the they have lost over the last 18 months or so due to injury and illness compared to him. At least for the Grand Tours that is.
I hope you don’t mind but I asked Chat gpt for an explanation. I’ve absolutely no idea whether its correct or a complete fabrication so please make of it what you will. Have a laugh or take note.
Key point up front
Fatmax and LT1 are not supposed to coincide, and in some athletes they can be very far apart.
Your numbers suggest:
High LT1 (good aerobic capacity, strong mitochondrial density)
Relatively low Fatmax power (fat oxidation peaks early, then drops sharply)
That combination is not contradictory — it reflects how substrate use shifts, not aerobic capability.
Why Fatmax can be much lower than LT1
1. Fatmax = peak fat oxidation, not “aerobic threshold”
Fatmax is the power where absolute fat oxidation (g/min) is highest, not where fat is still dominant.
As intensity rises:
Fat oxidation initially increases
Then carbohydrate use rises faster
Fat oxidation peaks and declines, even though metabolism remains aerobic
So:
LT1 = “still metabolically steady”
Fatmax = “sweet spot for burning the most fat per minute”
These are measuring different things.
2. High carbohydrate reliance despite strong aerobic fitness
In some endurance athletes:
Glycolytic flux ramps up early
PDH activation is strong
Carbohydrate oxidation displaces fat early
This can happen with:
Long history of high-intensity training
Frequent carbohydrate availability
Strong sympathetic response to exercise
High type IIa fibre recruitment even at moderate powers
Result: Fatmax occurs at surprisingly low watts LT1 remains very high
3. INSCYD specifically tends to show lower Fatmax
INSCYD often estimates Fatmax conservatively because:
It models fat oxidation based on lactate kinetics
Any early lactate rise suppresses modeled fat oxidation
Athletes with steep lactate curves get lower Fatmax outputs
So if lactate begins rising even gently by 160–170 W:
Fatmax will be pushed downward
Even if physiologically fat use remains substantial above that
This is a known artifact, not necessarily a flaw — just a modeling choice.
4. High LT1 + low Fatmax often means “fat efficiency, not fat power”
You can think of it this way:
Metric
What it reflects
Fatmax (W)
Where fat oxidation peaks
LT1 (W)
How much power you can sustain aerobically
Gap between them
How quickly carb metabolism dominates
A large gap often means:
Excellent aerobic machinery
But fat oxidation doesn’t scale well with intensity
That does not mean poor endurance — it means fuel preference shifts early.
Why your Z2 confusion makes sense
You’re intuitively spotting a real issue:
ISM Z2 just below LT1 → 210–215 W
Steve Neal “low Z3” → 230–235 W
Fatmax → 155–165 W
That feels wrong because people often assume:
“Z2 = fat burning”
But in reality:
Fat is still used above Fatmax
It’s just no longer maximal
Z2 can be predominantly aerobic but carb-heavy
So Z2 ≠ Fatmax
Z2 = metabolic stability, not substrate preference
When this pattern is common
This exact profile is often seen in:
Highly trained cyclists
Riders with good FTP/LT1 but “carb-leaning” metabolism
Athletes coming from threshold / VO₂-heavy blocks
Riders who fuel aggressively (which isn’t wrong)
Practical implication (no advice, just interpretation)
Such an athlete typically:
Can ride long and hard aerobically
Will burn more carbs than peers at the same %FTP
Benefits more from fueling strategy than from chasing Fatmax watts
Should not anchor endurance rides to Fatmax power alone
Using Fatmax as a training ceiling here would underload the aerobic system.
Bottom line
There is no contradiction in:
High LT1 (210–215 W)
Much lower Fatmax (155–165 W)
They describe different aspects of metabolism, and the gap actually tells a useful story:
Aerobically strong, but fat oxidation peaks early as intensity rises.
If you want, next we can:
Map this profile to durability over 4–6 hours
Explain why some pros show the same pattern
Or reconcile this with Seiler / ISM / Neal zone models without hand-waving
Maybe I just have too much fast twitch fibres type IIa. Also genetically more of an explosive athlete, rather then an endurance. But with lots of cycling already build some ok endurance fitness. But with an inefficient fat/carb engine under the hoods…
Oh god, please leave the AI chat crap in its box. Anyone wants to ask an AI, they can do it themselves, but no post it here in what should be a human to human forum.
Already asked another user in this thread to stop copy-pasting AI spam.
It’s not helpful or accurate unfortunately for this subject area.
This is also a public discussion board. As a general rule, you will find other people are not interested in hearing about conversations you had with an LLM.
Copy-pasting LLM answers into group discussions is generally not helpful for anyone, and is already viewed by many as a social taboo.
Well the person who asked the question didn’t seem to mind and hopefully was vaguely amused by it. So instead of advising me about social taboos perhaps you could point him in the right direction to satisfy his curiosity.
A more succinct answer though would have been something like “LT1 is not the same thing as fatmax.”
That would have answered their question while also not also creating a 3-page long essay everyone else needed to try and read, or at least scroll through
The main problem with these LLM copy-pastes are their length/verbosity, coupled with frequent inaccuracy.
Nothing wrong with using them if you like. The problem is they clutter the conversation for others. You can get around that by summarizing it in your own words instead
I have the same answer about Fatmax and LT1 from ChatGPT
For my case I have 2 Fatmax ~170-180W / ~200-210W
LT1 is around 240-250W now and the gap that is around 40W is good. (strong aerobic).
Training now is focus on moving LT1. (By doing only 2-3 hours per week at 235-245W / 3 sessions and around one hour per session) other training is consolidate 2 days and recovery 2 days.
I asked ChapGPT where is this method comes from. The answer is not clear but from his point of view as my coach. I will improve from this training in 4-6 weeks. (My LT1 will increase, if not it he will change the training)
Steve Neal also prescribes a moderate carb diet to encourage fat max which I’m sure would be controversial in 2025 if he was a big name. (I say that with love. I used Steve’s methods to achieve my highest fitness ever in recent years but I don’t agree with all of his ideas.)
Fatmax occurs at surprisingly low watts
. Thx 
