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GOVSS: Power Training for Runners

Written by Dr. Skiba

For a long time, runners and triathletes have looked at the promise of the power-based training options available to cyclists and thought, "Why can't I apply similar principles to running?"

The answer was, "You can't calculate power output for running athletes without very expensive laboratory equipment."

This has changed. After extensive research, Dr. Skiba developed a system to do exactly this utilizing the latest GPS technology. This systen also allows the quantification of your training load utilizing a system called GOVSS(TM) (Gravity Ordered Velocity Stress Score). Essentially, it generates a number that tells you how much stress a workout placed on your body. You can read a more in depth explanation at http://www.topofusion.com/govss.php .

Finally, this work was recently presented at a major medical conference, and the abstract published in a medical journal (Arch Phys Med Rehabil 87:29. Nov. 2006). A full length scientific paper is being prepared for publication. You can rest assured that GOVSS(TM) represents a fully thought out and developed system for measuring the physiologic training stress of running.

How Do I Calculate GOVSS?
Download the free demo of TopoFusion at http://www.topofusion.com. Follow the instructions on the website and you are good to go. You fill in some boxes in the software, download your GPS, and voila. You can record the power output and GOVSSTM score in your training log. The full version of the software will run you $40...well worth it, considering all the other cool stuff TopoFusion does. Our software, RaceDay, also does this. Click on the Software link for details.

How Does It Work?

Warning: Scientific mumbo-jumbo below...

This algorithm was inspired by previously validated energetics modeling, and works on the premise that it is possible to accurately model (r^2=.99) the energetics of running distances between 800M-42KM.

Translation: Scientists developed math that allows us to figure out power output for distances from 800M-42KM.

The above models were validated for flat courses, and for hilly courses, but not downhill mountain running races.

Translation: The math works great for most running, not quite as well for long downhills run all-out.

First of all, the energy cost of running changes with the grade of the road...it takes more energy to run uphill at the same speed than it does to run on the flat. So, we obtain the energy cost of running using a polynomial regression, which calculates the energy cost of running based upon the gradient of the road surface. The calculator also takes into account the energy cost of overcoming aerodynamic drag as well as the energy cost of changes in velocity during the run.

Translation: It takes more energy to run uphill, overcome air resistance, and change speed. The math takes this into account.

Now, the next thing to understand is this: Efficiency is calculated linearly ...the faster you run, the more efficient you become and the more of the power requirement is met by the elastic rebound of your muscles and soft tissues. In other words, going faster takes more power, but less than you would think because your muscles and tendons give you more bounce per step. This brings us to the next point: This model calculates the external contractile power output of your muscles. In other words, it "subtracts out" the power you generate through the elastic rebound of your tissues. In the purest sense, you are putting out WAY more power than this thing calculates...but all of that extra power is from the previously mentioned "spring" of your soft tissues, and not something "active" that you are doing.

Translation: You get more efficient by running faster, because your muscles and tendons "spring" like rubber bands. The math corrects for this.

Now, for the assumptions of the model:

1. The model assumes still air...i.e. no wind, and does not take into account barometric pressure or temperature changes, which we may address later.

Translation: It takes more energy to run on a very windy day. The math does not yet adjust for this, but it does not make a huge difference.

2. Because of the averaging required, this worksheet is really is not appropriate for instantaneous measurements of power output in the same way a power meter does it for a bicycle. There are models for 100M running that have been developed that consider running on an instantaneous basis, however, they would overestimate certain things and are not appropriate to for application to longer distances.

Translation: The math looks at the "big picture", smoothing out small bumps in pace, etc.

3. This model considers the horizontal and vertical energy cost, power output, and efficiency together.

Translation: The math looks at the "whole you", and does not attempt to adjust for how high you bounce during your stride versus how far that stride carries you forward.

You Need The Following to Continue:

TopoFusion (Demo): www.topofusion.com
The development of the GOVSS algorithm

Thanks and have fun with this!