DFA alpha 1 is a heart rate variability (HRV) metric that allows tracking of the aerobic and anaerobic threshold. We explain the breakthrough potential of this new metric and how you can track your DFA alpha 1 thresholds with the AI Endurance app, Garmin and Zwift.
TLDR: In short, DFA (detrended fluctuation analysis) alpha 1 measures the noise spectrum of your heart. As you ramp up the intensity of a workout and your heart has to work harder, the kind of noise - which the value of DFA alpha 1 represents - changes. Recent research has shown that DFA alpha 1 crosses below 0.75 at your aerobic threshold [1] and below 0.5 at your anaerobic threshold [2]. For a more detailed explanation, check our in-depth blog post about DFA alpha 1.
DFA alpha 1 might prove to be a groundbreaking advancement to correctly set our training zones and track fitness. It only requires you to wear a heart rate monitor that tracks HRV (Polar H10 recommended). This way, you will be able to
Imagine being able to detect your fitness level during most activities that are hard enough to cross either threshold, without even thinking about fitness testing. This is what AI Endurance does.
You can use real time logging of HRV data as well, see for example the HRV Logger by HRV4Training (Android and iOS) or FatMaxxer (Android). Your DFA alpha 1 data is available for each activity under "View Analysis" for your past activities in the AI Endurance Dashboard.
We attempt to automatically detect your thresholds for any activity with HRV data if the ramping is sufficiently slow. For the aerobic threshold this means at least 4 min of continuously decreasing DFA alpha 1 past 0.75. For the anaerobic threshold, we need at least 6 min of continuously decreasing DFA alpha 1 past 0.5.
We also detect thresholds via clustering: a cluster threshold is the average of all pace/power values recorded during the first 30 minutes of an activity with DFA alpha 1 values close to 0.75 (0.5). Generally, cluster thresholds are more abundant than ramps.
Our AI automatically takes into account the detected thresholds from ramps and clustering for your performance predictions. No more fitness testing anxiety and fatigue - focus on your training plan and we’ll detect your thresholds automatically over time and keep your digital twin up to date.
We have also created dedicated ramp tests for cycling and running in the AI Endurance app. These make it as easy as possible for you to accurately test your DFA alpha 1 thresholds with Garmin and/or Zwift. Simply go to your AI Endurance Apps page and either
In both cases, you need Garmin Download to be connected to AI Endurance.
The aerobic threshold sets the upper bound of your Endurance training zone. Conversely, the anaerobic threshold sets the upper bound of your Threshold zone [4].
We automatically keep track of your training zones over time. As your fitness evolves, we notify you if your DFA alpha 1 data indicates an update to your zones might be warranted.
There are different options on the market for optimized AI training plans that are based on applying machine learning to your individual data. In this post, we compare the different options and their features.
by Grant Paling. In my last blog, I closed the chapter on my European Championship race in Portugal. It definitely was an intense period leading up to, during and after the race. So many emotions, so much effort invested and then…what’s next?
by Stefano Andriolo. Building on previous work, we refine a method to accurately determine the relationship between DFA alpha 1 and power. This method can be used to track fitness and thresholds of an athlete. We find in some cases ramp detection tends to overestimate thresholds, a finding mirrored in recent physiological papers. On the other hand, thresholds based on clustering of DFA alpha 1 values tend to agree well with this new method. We propose a hybrid lab and everyday workout experiment to further study the relationship.
In this post, we give a short introduction to the running training zones and cycling training zones we use to structure your training. We use 5 training zones defined by pace for running activities and by power for cycling activities. AI Endurance calculates these zones for you individually based on your past training data.
