Utilizing and Understanding Quadrant Analysis, Pt. 1 - Set Up

Thursday, July 12, 2012 | By Jim Vance
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If you’re using a power meter, chances are you understand that power is simply the product of how hard we push down on the pedals (force), and the speed at which we turn the pedals (cadence).

Athletes can increase power output (watts) by pressing harder on the pedals, pedaling at a higher cadence, or both. But which of these should one do and when? The answer to that question is as varied as the different events in cycling and triathlon alone. However, using the Quadrant Analysis feature within TrainingPeaks and WKO+ can give athletes and coaches a better idea of which cadence and force relationship is the right one for their specific event or goals; as well as what their tendencies, strengths and weaknesses are.

In TrainingPeaks, Quadrant Analysis (QA) is available in the Maps & Graphs window. But the information and data needs to be specific to the athlete, so that the inferences made on the data will lead to better training and racing.

So how do you find the Quadrant Analysis in TrainingPeaks? When in the Map and Graphs window, there’s a drop down menu in the top right. Select QA.

Once you open the QA for the file, you can expand the view to full screen to see the items better.

The QA has cadence on the bottom, (Circumferential Pedal Velocity, or CPV), measured in meters/second, (m/s), and force on the left, (Average Effective Pedal Force or AEPF), measured in Newtons, (N). The threshold wattage of the athlete is the curved line going thru center, set in the user settings for the athlete. This chart and the different quadrants, (I, II, III and IV), was explained very well in a series of posts here on the TrainingPeaks blog by Hunter Allen. (You can read about the basics of quadrant analysis in Part 1.)

But it is important that athletes set this up properly, in order to keep the information accurate for analysis. One of the ways to do this is make sure your bike equipment is set up in TrainingPeaks correctly, because the bike you ride makes a difference.

In the equipment tab in your athlete settings, enter the information for the bike you ride. You should be sure to include the measurement of the crank arms, (likely somewhere between 165-175mm). The crank length (CL) is important, because this is the lever you use to apply force. Longer levers may allow athletes to push with more force, but they tend to move slower than shorter levers. Longer levers also require a greater arch speed at the pedal than shorter levers, for a given cadence.

When you log your ride in TrainingPeaks, your bike measurements for the crank arm are the basis for the settings in the QA, so be sure the information is accurate. Now you can see where the relationship of cadence and force begin, and how your ride was distributed across this spectrum.

The other main setting which needs to be addressed for this chart is the athlete’s threshold cadence (T-cadence). This is simply the cadence that the athlete rides at when riding at threshold. This is an important setting because it helps set the basis of the neurological cost of cadence for the athlete. For example, if during a 40K TT you tend to ride at 100 rpm, and another athlete does it at 90, a cadence of 95 rpm is below threshold effort for you, but above threshold for the other.

If you are unsure what your cadence tends to be when you ride or race at threshold, you can review a 40K TT you did either in an Olympic distance triathlon or standalone TT. If you don’t have one of those, just review some workouts where you did threshold intervals, and see what the average cadence was for ALL the intervals you did at that intensity.

Finally, be sure that your Functional Threshold Power (FTP) is up to date within your settings. You can find FTP under the "Zones" tab of your Account Settings. Click on "Power" and be sure your Threshold Power is accurate. The discussion of FTP is a topic and of itself, and we assume that most readers interested in QA have an understanding of FTP, but if not a great place to start would be to read Andy Coggan's article on FTP here.

When you manipulate these values, (FTP, crank length, and T-Cadence), it moves the center point of the graph. Since most of the samples in the graph tend be centralized, a small shift in a certain direction can dramatically change the distribution of the samples in the quadrants.

Now you can start viewing the QA section with the data specific to your equipment and fitness level, to better understand how you ride, and how to adjust your training to match the specific needs of your races and goals.

In the next post, I will show how we can use the QA to assess a finish sprint in a race, how the athlete did, and what is needed to improve. 

Read more of Jim's tips on how to use TrainingPeaks to track and further your fitness, including how to use Peak 30 Minute Power values for fitness tracking (formerly known as CP30 values), and how to use Peak Power or Peak Pace charts (formerly known as Mean Max Power or Mean Max Pace). You can also read more about Quadrant Analysis in the series Jim references by Hunter Allen.

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