A Smarter FTP Alternative: Why Our Physiological Testing Beats FTP or Lab Testing
- Jake Hollins
- Mar 5
- 4 min read
Updated: 5 days ago
For years, FTP (Functional Threshold Power) has been cycling’s default performance metric. Ride all-out for 20 minutes, take 95% of the average power, and you have your number. From that single figure, your training zones are set.
Simple. Standard. Yet incomplete.
Our free physiological testing replaces that single estimate with a full profile built from how your body actually produces energy. It’s done on your own bike, on familiar roads, using your real training data. And within the Topp Cycling platform, the model is updating continuously, every time riders upload training data.
Why We Need an FTP Alternative
FTP estimates the highest power you can sustain for about an hour; your threshold. That’s the point where your aerobic system (oxygen-based, sustainable energy) and anaerobic system (fast energy that produces lactate) are in balance.
Below threshold, lactate clears. Above it, lactate accumulates quickly.
So FTP gives you one number on one day. Useful, but limited.
FTP also doesn’t tell you your VO₂ max, your anaerobic production (VLa max), where fat burning peaks (fat max), or how your physiology shifts with training.
For example, two riders can have the same FTP, yet completely different engines. They might produce identical 20-minute power, but one could be burning far more glycogen to do it. In racing, that fuel efficiency difference often determines results.
Our Bodies are Hybrid Engines
Performance is the interaction between the two systems, like a hybrid car with two engines.
Your aerobic system determines how efficiently you sustain effort, burn fat, and clear lactate.
Your anaerobic system provides explosive energy for sprints and attacks, but it also produces lactate and increases carbohydrate reliance. Athletes with high anaerobic output are powerful, yet often endurance isn’t there.
Threshold power is simply where these two systems intersect. An athlete with a large aerobic engine with low anaerobic production typically produces a strong, durable threshold. A highly anaerobic athlete may reach the same FTP number in a very different, less efficient way. FTP alone cannot see that distinction.
What FTP Misses, And How Our Model Fills the Gap
FTP tells you how much power you can hold for roughly an hour. What it doesn’t tell you is how you’re producing that power. That’s where real performance insights live.
Take lactate, for example. Your anaerobic system produces lactate, and your aerobic system can use it as fuel. At threshold, lactate production and clearance are balanced. Push harder and production outpaces clearance, fatigue builds quickly, and you’re forced to slow down.
FTP identifies the tipping point. But it doesn’t explain what’s happening underneath.
It doesn’t show:
When your body shifts from primarily burning fat to relying heavily on carbohydrates
The intensity where fat burning peaks
How much your anaerobic system is contributing
Whether you’re efficient or strong
Our physiological model (based on the work of Alois Mader), maps these interactions.
One of the most important markers we identify is fat max, the intensity at which fat burning is highest and aerobic development is strongest. For many riders, this sits slightly higher than expected, often closer to upper endurance than easy spinning. Train below it and the stimulus is too small to drive adaptation. Train above it and you begin stressing the anaerobic system instead.
FTP cannot locate this point. Our FTP alternative can. This enables training to target the exact system you’re trying to improve, rather than relying on broad percentage-based zones.
When Faster Doesn’t Mean Higher FTP
If your 20-second sprint improves dramatically, your anaerobic production has likely increased. That can actually suppress threshold power, meaning FTP might drop slightly despite clear performance gains.
FTP would only show the lower number. Our model explains the why.
We also measure anaerobic work capacity (AWC) — effectively the size of your battery. VLA max determines how powerful your surge is; AWC determines how long you can sustain it. FTP ignores this completely, yet it’s crucial for racing and repeat efforts.
Why Lab Testing Isn’t the Answer Either
Lab testing uses gas analysis masks and blood lactate samples to build a profile. While accurate, it’s expensive, infrequent, and still just a snapshot.
Our system builds your profile from real-world riding (your own bike, familiar roads) and updates it continuously. Instead of being perfectly accurate once a year, you get a model that evolves with your training.
The Bigger Picture
A sprinter and an Ironman athlete can share the same FTP while being physiologically really different. One relies on explosive anaerobic power and fatigues quickly (think cheetah); the other is fuel-efficient and can sustain effort for hours (think migrating goose). FTP compresses both into a single number.
And we know performance isn’t one static metric, it’s a dynamic system.
Our free testing delivers a full physiological profile, identifies VO₂ max, VA max, AWC and fat max, explains your threshold rather than estimating it, and continuously adapts using your own riding data.
FTP was a useful shortcut. But if you want to understand how your engine truly works, and train with precision rather than best guesses, it’s time to move beyond it.
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