Blog
News, research, and training insights.
Updates on TrueZone development, validation studies, and insights from exercise physiology and metabolic health research.
We tested 297 cyclists. Here's what FTP gets wrong.
FTP assumes every rider can sustain their lactate threshold for 60 minutes. We tested 297 cyclists and found that's only true for a narrow slice of the population.
3 parameters vs 270,000 runs: how TrueZone matches Apple's model
Apple trained a deep neural network on 270,000 runs from 7,465 users. TrueZone matches their accuracy with a physiological ODE and three parameters.
The parameter that no wearable measures
Every fitness tracker estimates VO2max. None of them measure endurance. That's a problem, because endurance is what actually determines how far you can go.
What GPS vests miss about your players
Every professional team tracks distance, speed, and sprint counts. Almost none of them track the physiological cost of that work — and the data to do it is already there.
Your zones are wrong — and it's not your watch's fault
Fixed-percentage heart rate zones ignore the one variable that determines where your thresholds actually fall: endurance.
Metabolic fitness: the health metric hiding in your heart rate
Cardiorespiratory fitness is the strongest predictor of all-cause mortality. It's also almost never measured — because the test requires running to exhaustion in a lab.
Why maximum speed is a limiting factor for endurance performance
Maximum speed has not been widely used as a fitness metric and especially not for endurance athletes but is in fact, instrumental in dictating performance.
Why endurance matters for your training zones
Heart rate zones are important to know if we want to train efficiently. Unfortunately it can be difficult to know our true heart rate zones.
The Discovery of Endurance
If you are reading this blog then surely you must have witnessed Eliud Kipchoge's epic breaking of the 2-hour barrier in the marathon in Vienna in 2019.
Your True Exercise Thresholds
Exercise thresholds have been defined as boundaries between different domains of exercise intensity. They are used by medical professionals to clinically assess patient physiological function or dysfunction, such as heart failure, diabetes, peripheral artery disease, and suitability for surgery or transplant.
Cracking the Heart Rate Code
Wow, 3.6 billion! In years, that‘s about the entire history of life on Earth. In people, that‘s about the coverage of Zuckerberg’s Metaverse. But in your chest, that's about the number of times your heart might beat should you be so blessed to live into your old age!