MPA Analysis and Fitness Signature Extraction
Xert takes a very different approach in establishing your fitness numbers. By analyzing your regular activity data and performing MPA Analysis, your Fitness Signature can be extracted from the data. This includes not just your Threshold Power, but also your High Intensity Energy and your Peak Power too – all three of which define your individual power profile. Fitness Signature extraction establishes your fitness by identifying those maximal efforts in your activity and uses a regression algorithm to determine a fitness signature that matches these points. You’ll find that whether you perform a specific test or whether you use a club ride, if the power data includes time spent doing a maximal effort, Xert can extract your signature. For example, take this 20 minute FTP test data:
You can see that the athlete’s MPA (blue line) starts at their peak power and slowly moves down until it reaches the power output (red line) at precisely the point that the athlete’s gives up (green diamond). The fitness signature that is representative of the athlete’s fitness signature at the time of this test is displayed at the bottom: Threshold Power = 328W, High Intensity Energy = 32.7kJ and Peak Power = 1460W. This same athlete also entered a local criterium, where their fitness was put to the test. Here is an MPA chart of the race. Where MPA dips towards the athlete’s power and eventually meets the athlete’s power, is representative of a point of maximal effort:
If we zoom in to this section:
You can see that athlete was close to MPA for quite some time. This was a tough race for them. At the moment their power reaches MPA, they get dropped. Signature extraction for this race data is shown below the chart. It is representative of their fitness at the time of the race and it is the same as the fitness signature from the 20 minute test.
Using Regular Activity Data for Signature Extraction
Xert enables you to upload your activity data and will perform signature extraction automatically when you upload your ride. This process determines your fitness signature parameters – Threshold Power, High Intensity Energy and Peak Power at the time of the activity. The key benefits to using Xert for fitness testing are as follows:
- Use regular activity data that contain maximal efforts;
- Avoid having to know in advance what your fitness numbers are in order to set your pace;
- This is especially useful if you are new to training with power data.
- Use variable efforts, including those containing periods of rest;
- Conduct your tests in a shorter amount of time;
- Obtain your Threshold Power and your Peak Power and High Intensity Energy;
- Test more often, even at the end of rides;
- Test before an event to know your numbers and confirm the event strategy;
- Avoid testing altogether if your regular training/group activities include time spent at maximal effort.