Monday, October 01, 2007

"Body" -> Part II: Modern Tools For Training

In the first installment of this series of posts, we discussed the idea that you need to track your workouts. Not only do you need to do this from a chronological standpoint, but you should also track this from a effort standpoint. However, distance alone (or time) is probably not sufficient to capture the state of your training body.

In cycling circles Andy Coggan (exercise physiologist and national age grouper bicycle time trialist) has derived what he calls a Training Stress Score or TSS. While having good success in using this formula for his own training, Andy released the formula in 2003 on the Wattage mailing lists.

While the Wattage mailing list has a small following, it is a powerful following. Very soon there were many people looking to use this TSS idea, and commercial implementation was not far behind.

The most widely used package using Coggan's formula is the CyclingsPeak WGO+ package. The user must have a powermeter. Now, bicycle powermeters are worth a post of their own, but for simplicity, there are at least three commercially available systems on the market. I happen to own the Powertap model for my racing bike and I also have a Polar model for my commuting bike. (I will do a post on this later.)

A Powermeter for a bicycle allows you to do your workout, and it tracks and logs the effort (power) that you are putting into the back wheel.

After the training is done, the user downloads his data to WGO+ to see his TSS. You can also use an Excel spreadsheet on Powertap data, which is found here. However, the spreadsheet is a bit old, and may not work with all versions of the Powertap.

As already mentioned, the easiest way of getting this information is to buy the WGO+ package. On the left is an example of the ride that I did this weekend with my Powertap computer. After my ride, I took the Powertap computer, which is the size of a normal bicycle computer, to my computer. Hooked it up to a USB port, and downloaded my training session of 63 miles. As you can see, part of the summary data is a TSS score. In this case, my TSS was ~277 at an intensity factor of .811. This means that I went far, but I didn't go all that hard.

~277 is still quite stressful, and I can always feel it after my 63 mile loop. I'm tired! Now, once you have the TSS, you can start tracking this in all of your workouts. What you'll quickly learn is pretty obvious: shorter hard workouts have a bigger impact per training minute than long workouts.

By monitoring your workouts in this fashion, you get a much better external feedback into your training methodologies. This method of training is being implemented by all levels, and you can find the professional bicycle racer is even tracking his (or her) output in races.

The one part that I've skipped over in all of this is the "relative starting point." If you are superfit, a hard workout might be 120 miles of hammering on the bicycle. If you are just starting out, maybe a 10 miler may leave you sore. To get the base level for fitness, you are required to take a time trial (or race pace). While there are many ways of getting this information, the easiest method is doing a 25 mile (40 km) time trial. Once you have this data, you can then base all other workouts against this key workout. The key statistic in determining your base fitness is figuring the power that you can generate for roughly one hour. There is a place in the software to insert this data.

However, this is a blog about triathlons. We know that bicycling isn't the only sport in the triathlon. Has there been any work on other sports?

The question of how to do this for running has been, in some sense, solved by Philip Friere Skiba with his GOVSS (Gravity Ordered Velocity Stress Score). You do need to have a GPS for running and Garmin with their Forerunner series of GPSs have pretty much cornered the market on this application. You must have a GPS that logs the running data! A few of the cheap Garmin units do not log this data.

Once you have your GPS, you load it into TopoFusion, which has a free demo package of their software and decide to implement Skiba's formula. Once you have selected your run, you can do an analysis on your run, and you will see a box like the following.

Now, similar to the TSS of bicycling, the software needs someway of figure out what your base fitness level is. Therefore, you also need a time trial to establish base fitness. Once you have done this, then you can analyze any run in the package to get an "average power."

How do you do this? Average power is calculated for every run, and you'll use this calculated figure to set the base.

Similar to the bicycle methodology, you take a very hard run (or time trial), and it will give you an average power. Now you'll use this as the GOVSS base.

In this case, I generated and average power of 345 watts in a 6.5M time trial in my local area a few months ago. If you look at the box above, I then inputed 345 watts into the "input" box. This now becomes the calculated score.

I'll leave the average power there for a long time. However, if I got a lot more fit, I should take another trial to establish a new base.

With my svelte 200 lb frame on my 8 mile run last night, I had a GOVSS score of around 114. The lactate score is a prediction of the power that I would generate for a 1 hour run. The average showed what I did last night. Now, while my peak power was 345 Watts for my time trial, I "only" generated 286 Watts during my run. However, I went for a long time, thus while I went at a lower intensity, I went longer. Thus the stress score was pretty high.

Also, note that the Kcal expended is post conversion. The software shows calories as work, not calories burned in the body. When you do work, 80% of calories get lost as heat! Now you know why exercising makes you so warm. Working out at 200 watts is like having 800 watt heater on you.

If you keep in mind that the body conversion to work is around 4-5:1, my calories burned was around 1312-1640. Considering I climbed almost 700 ft in elevation during the run, and the 1312 calories doesn't sound too far off.

What is interesting, is that last night's training running is almost exactly the same GOVSS as as my 6.6M time trial, which took 52 minutes. So, it I was doing the same number of GOVSS per week, I could do it as 3 sessions of my 6.6M time trial or as 3 session of 8.1M longer run with more hills.

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