Power Analysis - Manual
'Edit activity' Actions
These actions are available in the "Daily Activity" view 
and the "Reports" view 
of
SportTracks.
When you select one or many activities, only those actions are displayed that are applicable to the selected
activities.
Analyze Power
Only displayed when: one of the selected activities has a power track and a heart rate
track
This actions calculates the data that will be displayed on the plugin's activity detail page, based on the current
configuration values and saves the data with the activities.
You need not necessarily call this action, because the activity detail page will call it implicitly, when necessary.
Compare Power
Only displayed when: you have selected more than one activities with a power track and a
heart rate track.
This action pops up a power-over-time diagram that shows how your fitness develops over time.
Each line represents your power output at a given heartrate.
Improving fitness is indicated by ascending lines.
Note: You should have called "Analyze Power" for these activities before.
Note 2: This feature is still in development.
Activity Detail Pages
Power Analysis Activity Detail Page
This page consists of three major parts
- An upper part that shows several figures
- A line chart that shows heartrate, power and elevation over time
- A power vs. heartrate correlation chart
Power vs. Heartrate Correlation Chart
The rainbow colored bar inbetween this dot chart and the line chart above indicates the
color coding for the dots in the correlation chart. E.g. points taken at approx. 1:40h of this ride are coded in blue color,
dots at 2:50h in reddish tones.
The chart shows:
- An X-axis representing power and an Y-axis representing heartrate
- A cloud of points that each represent power and heart rate at a given point of time
during the activity.
Points are printed "Point distance" seconds apart.
The points are color coded. When you see that reddish points have a relative high heart rate
for the same power compared to blue points, you can see that your heartrate at the end of the ride has increased, e.g. due
to dehydration or excessive heat.
- A black line which is the best linear approximation of your heartrate vs. power
correlation.
The closer the points are grouped around this line the better the approximation (i.e. the higher the value of R^2).
-
Histograms that indicate the distribution of power and heartrate.
- The background shows colored bands that correspond to your heart
rate zones and power zones.
The zones labels show the zones' names and how long you stayed in the particular zone (percent, time and distance).
One last thing: click on the chart and you see that every click toggels the display mode: points only, points and lines,
lines only. Chose what you like.
Line Chart
This is a normal SportTracks line chart. You can zoom and pan both axes as usual.
When you select a time range in the chart by click and drag, only points in the selected time
range will be displayed in the correlation chart.
Figures
This part contains three columns:
-
Power Heartrate Correlation
These are the key parameters of the diagram below:
-
Heartrate(Power): this is the equation of the linear approximation of heartrate vs.
power
This is the thick black line in the diagram below.
In the example below, your heart rate will rise by 0.11 bpm for every Watt of additional output.
Your "dynamic resting heart rate" is 135 bmp (the heart rate at a power output of 0 W).
The lower both values are, the better your fitness.
-
Heartrate Delay:
When you increase your power output, e.g. start sprinting, your heartrate does not rise immediately but with a certain
delay. The plugin automatically detects the heart rate delay which results in the best linear approximation.
-
Averaging Interval:
Power and heart rate should be averaged over a certain interval to remove "signal noise": This is the value as configured
on the settings page.
-
Point Distance:
One point is drawn on the diagram every n seconds of "Point Distance".
-
Stability Index (R^2):
A statistical measure how good the linear approximation is.
A value of 0 indicates an arbitrary "cloud of points" with no significant linear relationship.
A value of 1 indicates a perfect linear relationship - all points reside on the line.
The value of 0.2663 below is rather bad. You should not trust diagrams with a R^2 value of less than say 0.4 too much.
-
Heartrate vs. Power
These are some key points of the thick black line below, i.e. the power that you output at given heart rates.
The higher, the better.
-
Training Intensity
These are measures, how intense your training was:
- Average Power (absolute and in Watt per kg of body weight)
- Average Heartrate
- Calories Spent
- Intensitiy Factor and Training Stress Score
- Threshold Power (as configured in the plugin settings)
Settings Pages
Power Analysis Plugin
This settings page allows you to configure parameters that determine how the power vs. heartrate correlation is calculated
and displayed:
- Averaging Interval
The linear approximation calculation averages heartrate and power values over this interval to remove "signal noise".
- Distance Between Points
One point is drawn every n seconds.
- Heart Rate Axis:
The lower and higher end of the heartrate axis (Y-Axis)
- Power Axis:
The lower and higher end of the power axis (X-Axis)
- Power Clipping:
Power values outside of this range will not be considered.
The default values are a reasonable start. When you understand what these values mean, you should try and play with
them.
Editing Your Threshold Power
When you click on the 
"Power Zones" button, a
dialog pops up:
You can view your power zones in this dialog and edit your threshold power.
Note: Previous versions of SportTracks did not support a concept of power zones. You had to edit your power zones in this
dialog. Since SportTracks now supports power zones, you no longer edit your power zones here.
When you've used older versions of this plugin before and start this verson for the first time, a message box might pop up
that reminds you to transfer your power zone definitions to the SportTracks settings.
Plugin Information
The "Plugin Information" panel is standard for all my plugins. See the General Features page for details.
Donation Wallet
The donation wallet is standard for all my plugins. See the "Donation Wallet" section on page General Features for details.
See page Validate your Donation for a step-by-step explanation how to validate your
donations.
Miscellenaous
The plugin adds three new documentation components to the Activity Documentation Plugin:
Documentation Components for the Activity Documentation Plugin
-
Power Heartrate Correlation
-
Performance Indicators
-
Training Intensity
Glossary
Training Stress Score (TSS)
A measure how strenuous a workout was (originally published by Andrew R. Coggan).
The following scale can be used as an approximate guide:
- Less than 150: low (recovery generally complete by following day)
- 150-300: medium (some residual fatigue may be present the next day, but gone by 2nd day)
- 300-450: high (some residual fatigue may be present even after 2 days)
- Greater than 450: very high (residual fatigue lasting several days likely)
cited from 
http://www.cyclingpeakssoftware.com/power411/defined.asp
Note: some cite "TSS" with a trademark sign, but I could not find a trademark registration for this.
Should anybody know that "TSS" is a registered trademark please let me know.
Intensity Factor (IF)
A measure for the intensity of this workout (originally published by Andrew R. Coggan).
Workouts with a constant heart rate at your anareobic threshold
will yield a value of 1.0 (100%).
Typical IF values for various training sessions or races are as follows:
- Less than 0.75 recovery rides
- 0.75-0.85: endurance-paced training rides
- 0.85-0.95: tempo rides, aerobic and anaerobic interval workouts (work and rest periods combined),
longer (>2.5 h) road races
- 0.95-1.05: lactate threshold intervals (work period only),
shorter (<2.5 h) road races, criteriums, circuit races, longer (e.g., 40 km) TTs
- 1.05-1.15: shorter (e.g., 15 km) TTs, track points race
- Greater than 1.15: prologue TT, track pursuit, track miss-and-out
cited from http://www.cyclingpeakssoftware.com/power411/defined.asp
Note: some cite "IF" with a trademark sign, but I could not find a trademark registration for this.
Should anybody know that "IF" is a registered trademark please let me know.
Threshold Power
The power that you can deliver at your anareobic threshold
(link to German wikipedia).
Further
Reading
tbd.
Send me interesting links or references to books and I'll publish them here.